Factors affecting productivity and habitat use of Florida sandhill cranes (Grus canadensis pratensis)

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Material Information

Title:
Factors affecting productivity and habitat use of Florida sandhill cranes (Grus canadensis pratensis) an evaluation of three areas in central Florida for a nonmigratory population of whooping cranes (Grus americana)
Physical Description:
xvii, 190 leaves : ill. ; 28 cm.
Language:
English
Creator:
Bishop, Mary Anne, 1952-
Publication Date:

Subjects

Subjects / Keywords:
Sandhill crane -- Nests -- Florida, Central   ( lcsh )
Whooping crane -- Nests -- Florida, Central   ( lcsh )
Genre:
bibliography   ( marcgt )
theses   ( marcgt )
non-fiction   ( marcgt )

Notes

Thesis:
Thesis (PH. D.)--University of Florida, 1988.
Bibliography:
Includes bibliographical references (leaves 179-189).
Statement of Responsibility:
by Mary Anne Bishop.
General Note:
Typescript.
General Note:
Vita.

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 001366485
notis - AGM7974
oclc - 20659034
System ID:
AA00003361:00001

Full Text
















FACTORS AFFECTING PRODUCTIVITY AND HABITAT USE OF
FLORIDA SANDHILL CRANES (Grus canadensis pratensis): AN
EVALUATION OF THREE AREAS IN CENTRAL FLORIDA FOR A NONMIGRATORY
POPULATION OF WHOOPING CRANES (Grus americana)





By

MARY ANNE BISHOP


A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN
PARTIAL FULFILLMENT OF THE REQUIREMENTS
FOR THE DEGREE OF DOCTOR OF PHILOSOPHY


UNIVERSITY OF FLORIDA


1988














A crane calling in the shade
Its young answer it.
I have a good goblet.
I will share it with you.
I Ching


This dissertation is dedicated to the memory of 2 friends: Jim
Chism (1908-1986), former Curator of Birds at the San Antonio
Zoological Gardens and Frank Johnson (1932-1986), former Refuge Manager
at Aransas National Wildlife Refuge, Texas.












ACKNOWLEDGMENTS


Numerous individuals provided assistance throughout my tenure as a

graduate student in the Department of Wildlife and Range Sciences, and

I wish to express my gratitude and extend my thanks.

In particular, I thank my friend and graduate advisor, M.W.

Collopy, for his encouragement and support during my field work and my

coursework. I also thank S. Nesbitt of the Florida Game and Fresh

Water Fish Commission for his invaluable assistance and guidance

throughout this study. For this dissertation he reviewed the

manuscript and attended by defense as an ex-officio member of my

graduate committee. K.M. Portier, also of my committee, has provided

many sessions of statistical guidance throughout this study. G.W.

Tanner, J.F. Eisenberg, and H. F. Percival have contributed valuable

suggestions and assistance both in the classroom and as members of my

committee.

This research was generously supported by several organizations

and individuals. I wish to thank the Florida Game and Fresh Water Fish

Commission and the National Audubon Society for their sponsorhip of my

project. I am grateful to the Florida Game and Fresh Water Fish

Commission, U.S. Fish and Wildlife Service, University of Florida,

National Audubon Society Research Department, the Sierra Club of

Florida, and the Henry L. and Kathryn Mills Charity Foundation for

their generous contributions to the project.

iii







Many individuals also helped make this study possible. P. Eddie

and Florida Game and Fresh Water Fish Commission pilots L. Ham and

J. Wisniewski flew most of the nest surveys. D. Chandler of Fellsmere

Management Farms and R. Clayton also provided airtime to track missing

radio-tagged cranes.

My assistants were invaluable throughout this project. N.

Schaffner and M. Franklin assisted during the breeding seasons and with

the telemetry. I also thank N. Schaffner for her help with the

monumental chore of baiting and trapping cranes. T. Ruth, J. Kappes,

and H. Dinkler also assisted with the telemetry. L. Walkinshaw,

P. Woods, H. Jelks, and K. Williams flew surveys when I was short-

handed. N. Dwyer digitized the vegetation maps and drew most of the

graphics. Many other individuals lent their able bodies during our

crane trapping sessions, and I thank them.

I am most grateful to the following agencies and their personnel

for their cooperation and hospitality over the past 5 years: Webb

Wildlife Management Area, Myakka River State Park, Ringling-MacArthur

Reserve, Three Lakes Wildlife Management Area, Prairie-Lakes State

Preserve, National Audubon Society Kissimmee Prairie Sanctuary, and the

Wildlife Research Lab and the Law Enforcement Divisions of the Florida

Game and Fresh Water Fish Commission.

The success of this study hinged on the goodwill of the private

landowners. I am most grateful to all those ranches who gave me access

throughout my field work. On the Webb Wildlife Management Area study

area I would like to thank the following ranches: L. Hudson Farms,

Pulte, Hitzing, and Babcock. On Myakka River State Park study area I

thank the following ranches: Hawkins, Hi-Hat, Mason (Albritton Fruit
iv







Co.), M. Carlton and Sons, Walton, B.T. Longino, and Carlton Rusty Pot

Ranch. I also thank Drs. A. and M. Jelks for their hospitality during

my stays in Sarasota.

Ranchers on the Kissimmee Prairie were always hospitable and

helpful throughout my field work. I would like to thank the following

ranches for allowing me access: Adams, Mills, Hayman 711, Billy Rogers

7 Lazy 11, Campbell's Escape, Leroy Bass, J. Chapman's Double C Bar,

Bar Seven, Whaley, Rollins, Latt-Maxcy El Maximo, T-Pee Beefmasters,

Bronsons, R. Overstreet, Blue Cypress, Tucker's Far Reach, Willowbrook

Farms, Fellsmere Management Farms, Deseret, River Ranch, R. Clayton,

Crosby, L.J. Harvey, H. Thomas, D. Carlton, Hyatt Farms, B. Geiger, and

Lucky L. A special thanks goes to Billy Rogers 7 Lazy 11 Ranch for use

of their airstrip.

I spent 2 1/2 beautiful years living on the Kissimmee Prairie. I

would like to especially thank Lee and Bud Adams of the Adams Ranch for

the opportunity of a lifetime to live and do field work on one of

Florida's greatest ranches. To the folks of the Mills Ranch: B.

Morris, K. Mills, N. and B. Seymour, I am thankful for their friendship

and assistance during my stay.

I would like to acknowledge and thank those who offered technical

assistance during this study. M. Fleming gave advice during the design

stages. J. Woods, P. Frederick, and B. Stith helped with computer

programs. I also thank J. Smallwood and H. Jelks for their statistical

consultations. R. Noss reviewed portions of the manuscript and offered

valuable suggestions. A special thanks to B. Abt and B. Hubbard for

use of their facilities to print this dissertation. P. and J. Woods
v







both have been helpful colleagues in many aspects of this study and

good friends throughout my years in Gainesville.

As always, I thank my family who have always encouraged my

aspirations. My cousin N. Schaffner has been a loyal supporter of the

project and contributed a year of her life to the cranes. I thank her

for her love and friendship. I am most grateful to my parents and my

sister Barb who have encouraged me at all times. To my old friends, L.

and S. Wren, my "sisters" in Texas: Rebecca, Pam, Cathy, Bride and

Lois, and especially P. Foster-Turley, I am grateful for your

support and friendship all these years.

Lastly, I would like to thank Larry and Claire Walkinshaw. The

Walkinshaws have been supporters of this project since its beginning.

Larry has always been willing to share his information and vast

knowledge of cranes. Without his pioneering work on Kissimmee Prairie,

this study never could have happened.













TABLE OF CONTENTS

Page

ACKNOWLEDGMENTS. . . ... iii

LIST OF TABLES . . ..

LIST OF FIGURES. . . ... .. xiii

ABSTRACT . . . vi

CHAPTERS

I INTRODUCTION . . ... .. 1

Justification. . ... .. 1
Objectives . . ... .. 3

II LAND USE STATUS AND TRENDS OF POTENTIAL RELEASE SITES... 6

Introduction . . ... .. 6
Methods. . . ... .. 7
Results. . . .. 8
C.M. Webb Wildlife Management Area .. 8
Webb Wildlife Management Area Surrounding Land Use
and Potential Threats . ... 14
Myakka River State Park .. . 18
Myakka River State Park Surrounding Land Use and
Potential Threats . ... 22
Three Lakes Wildlife Management Area. .. 25
Management on Three Lakes Wildlife Management Area.. 29
Prairie-Lakes State Preserve. . ... 30
National Audubon Society Kissimmee Prairie Sanctuary. 31
Surrounding Lands and Potential Threats to Three
Lakes WMA/Prairie-Lakes State Preserve and Kissimmee
Prairie Sanctuary . ... 32
Discussion . .. .. 38

III PRODUCTIVITY OF FLORIDA SANDHILL CRANES ON THREE SITES
IN CENTRAL FLORIDA . ... 43

Introduction . . ... ... 43
Methods. . . ... 46
Aerial Surveys of Nests . .. 46
Sampling regime. . ... 46
Areas surveyed . . 52
Detectability. . ... 54







Breeding pair population estimates ...... 54
Environmental Correlates of Nesting Densities 56
Nest Site Characteristics . ... 57
Fall Juvenile Recruitment Surveys ... 57
Results. . . ... ..... 58
Nesting Chronology and Density. . .. 58
1984 Breeding season . ... 58
1985 Breeding season . ... 65
1986 Breeding season . .. 74
Population Estimates and Confidence Limits. 80
Transect Repeatability Between Flights. ... 86
Bias in Aerial Surveys. . 86
Quadrat estimates compared to fixed-strip
estimates. . . ... 88
Front and back seat observer differences 88
Effect of flight speed on nest detectability 89
Environmental Correlates of Nesting Densities 95
Nest Site Characteristics and Evidence of Hatch
Success . . ... ... 97
Wetland characteristics. . .. 97
Surrounding habitat characteristics. ... 98
Ownership status . .... .101
On-site nest visits. . ... 101
Brood Size and Annual Juvenile Recruitment. ... 104
Discussion . . ... 106
Validity of Aerial Survey Estimates ... 106
Length of Breeding Season . 109
Proximate Factors Influencing Breeding Initiation
and Renesting . .... .109
Initiation of breeding . ... 110
Affects of ditching . .... .112
Renesting. . ....... 112
Comparison of Nesting Densities and Annual Juvenile
Recruitment .................. 113
Breeding pair density estimates. ..... 113
Juvenile recruitment rates . ... 114

IV HOME RANGE OF FLORIDA SANDHILL CRANES ON THE KISSIMMEE
PRAIRIE, FLORIDA. . . ... 116

Introduction . . .. ... 116
Study Area . . .. 118
Methods. ................... .... 119
Determination of Home Ranges. ......... 119
Habitat Use . .... 124
Social Behavior . .... .125
Results. ................ .. ... 126
Variations in Home Range Size and Overlap 126
Nest Site Selection . ... 135
Diurnal and Seasonal Habitat Use. ... 138
Habitat Selection. ... . 143
Nocturnal Habitat Use . .... .145
Social Behavior . ..... 146


viii







Discussion ..... .. . ... 149
SHome Range Size . .. 149
Ecological and Behavioral Determinants of Home Range 151
Habitat Selection .... .. 155
Social Behavior . ... .. 156

V CONCLUSIONS AND MANAGEMENT RECOMMENDATIONS .. 158

Florida Sandhill Crane in Central Florida. ... 158
Monitoring Florida Sandhill Crane Population .. 159
Potential for the Reintroduction of Whooping Cranes. 160
Recommendations. . . ... 161

APPENDICES


A MAP OF WEBB WILDLIFE MANAGEMENT AREA .. 165

B MAPS OF THREE LAKES WILDLIFE MANAGEMENT AREA AND
PROPOSED THREE LAKES WMA/PRAIRIE-LAKES STATE PRESERVE
ADDITION . . .. 167

C LOCATION AND OWNERSHIP OF NEST WETLANDS ON 3 SITES IN
CENTRAL FLORIDA. . . ... 169

D SPEARMAN RANK CORRELATION BETWEEN BREEDING DENSITIES
AND ENVIRONMENTAL VARIABLES. . ... 177

LITERATURE CITED . .... . 179

BIOGRAPHICAL SKETCH . . 190













LIST OF TABLES


Page

2-1. Human population growth and forecasts by county for
selected areas in central Florida . .... 16

2-2. Approximate size (ha) of large private and public
landholdings on and near the Kissimmee Prairie, Florida.
Starred ranches border Three Lakes Wildlife Management
Area. . . ... 33

3-1. Total precipitation and departure from normal (cm) on 3
study areas in central Florida for 1 May 1983 30 April
1984 ... ... 59

3-2. Peak nesting date by year as determined from aerial
surveys . . ... ...... 64

3-3. Total precipitation and departure from normal (cm) on 3
study areas in central Florida for 1 May 1984 30 April
1985 .. . .. .... 66

3-4. Estimated crude density (R), and estimated total breeding
pair population for 3 study areas in central Florida.
Estimates based on initial nest sightings on aerial
transects, 1985 and 1986. . ... 67

3-5. Total precipitation and departure from normal (cm) on 3
study areas in central Florida for 1 May 1985 30 April
1986. . . . .. 78

3-6. Estimated breeding pairs (Y) and 95% confidence intervals
(CI) determined from aerial fixed-strip transect surveys
Sat 3 areas in central Florida, Spring 1984. 81

3-7. Comparison of estimated breeding pairs (Y) and 95%
confidence intervals (CI) determined from aerial fixed-
strip transects with estimates from intensive aerial
searches of 3 km x 3 km quadrats at 3 areas in central
Florida, Spring 1985. . . ... 82

3-8. Estimated breeding pairs (Y) and 95% confidence intervals
(CI) determined from aerial fixed-strip transect surveys at
3 areas in central Florida, Spring 1986 .. 84

3-9. Percent of nests on aerial transects observed during more
than one flight, 1985 and 1986 breeding surveys .... 87







3-10. Seasonal Florida sandhill crane breeding pair population
estimate (Y) and +95% confidence interval (CI) based on
initial transect nest sighting for front seat and back
seat observer . .... ..... 90

3-11. Comparison of nests sighted and estimated breeding pair
population (Y) and 95% confidence intervals determined from
fixed-wing aircraft and helicopter surveys of six 3 km x
3 km quadrats for each study area during 1985 .. 92

3-12. Comparison of nests sighted on 6 fixed-strip transects from
a fixed-wing aircraft with nests sighted from a helicopter
the following day, Kissimmee Prairie, 1986. .. 93

3-13. Comparison of nests sighted on 6 fixed-strip transects from
a fixed-wing aircraft on 29 January, 1986 with nests sighted
from a helicopter the following day, Myakka River SP and
Webb WMA. . . ... ..... 94

3-14. Average size, range, and proportion ditched of the nest
wetlands (ha) in which Florida sandhill cranes nested for
3 areas in central Florida. . ... 99

3-15 Percent ownership status of Florida sandhill crane nest
wetlands for 3 areas in central Florida based on nest
and flightless-chick sightings, 1985 and 1986.. .... 102

3-16. Outcome of visits to nest wetlands on Kissimmee Prairie,
Spring 1986 . . ... ..... 103

3-17. Mean brood size and number of juveniles in the population
during August-October road surveys, 1984-1986 105

4-1. Annual home range size (ha) of Florida sandhill crane
paired adults and chicks using 3 methods, October 1985-
January 1987. . ... ..... 129

4-2. Summary of breeding attempts by radio-tagged Florida
sandhill cranes on Kissimmee Prairie, Spring 1986 132

4-3. Seasonal home range size (ha) of Florida sandhill crane
paired adults and chicks, Kissimmee Prairie, Florida,
October 1985-January 1987. . .133

4-4. Annual home range size (ha) of unpaired adult and subadult
Florida sandhill cranes, Kissimmee Prairie, Florida, October
1985-January 1987 . .... .136

4-5. Percent of diurnal locations, and available habitat within
the annual home range (modified minimum convex method) for
4 paired adults and 2 chicks on the Kissimmee Prairie,
Florida, October 1985-January 1987. . 140







4-6. Use of cover types by 4 paired adults and 2 chicks on the
Kissimmee Prairie during October 1985-January 1987. 144

C-1. Ownership and location (township, range, section, and quarter
section) of nests and flightless chicks located during 1985
and 1986 on and around Myakka River State Park study area.
Nests located by local informants are noted by initials 169

C-2. Ownership and location (township, range, section, and quarter
section) of nests and flightless chicks located during 1985
and 1986 on and around Kissimmee Prairie study area. Nests
located by local informants are noted by initials 171

C-3. Ownership and location (township, range, section, and quarter
section) of nests and flightless chicks located during 1985
and 1986 on an around Webb Wildlife Management Area study
area. Nests located by local informants are noted by
initials. . . ... ..... .175

D-1. Rho and P-values for Spearman rank correlations between
densities of breeding Florida sandhill cranes detected from
aerial surveys and environmental variables. .. .177

D-2. Rho and P-Values for Spearman rank correlations between
densities of breeding Florida sandhill cranes detected from
aerial surveys and water levels preceding surveys. All
correlations are significant P < 0.01 ... .178


xii













LIST OF FIGURES


Page

1-1. Locations of 3 proposed whooping crane release sites in
central Florida. . . ... .. 4

2-1. Map of C.M. Webb Wildlife Management Area and surrounding
lands. . . ... . 10

2-2. Habitat composition for proposed whooping crane release
sites in central Florida: Webb Wildlife Management Area
(WMA), 26,455 ha; Myakka River State Park (SP), 11,690 ha;
National Audubon Society (NAS) Ordway-Whittell Kissimmee
Prairie Sanctuary, 2,955 ha; and Three Lakes Wildlife
Management Area (WMA) and Prairie-Lakes State Preserve,
11,920 ha, but excluding the 7,150 ha north of the Florida
Turnpike . . ... 11

2-3. Map of Myakka River State Park and surrounding lands 19

2-4. Map of Kissimmee Prairie study area including Three Lakes
Wildlife Management Area, Prairie-Lakes State Preserve and
National Audubon Society Ordway-Whittell Kissimmee Prairie
Sanctuary. All Florida Game and Fresh Water Fish Commission
Wildlife Management Areas are stippled ... 27

3-1. Florida sandhill crane nesting season and the average monthly
-*p** rainfall (cm) for November through October on the Kissimmee
Prairie, Florida . . ... ... 47

3-2. Layout of a systematic aerial fixed-strip transect survey
using 3 km x 3 km grid mapping on the Webb Wildlife
Management Area, Florida. Boundaries of Management are
shaded . . ... .... 49

4 3-3. Diagram of plane height and observer strip width used during
systematic aerial transect surveys for breeding Florida
sandhill cranes on 3 sites in central Florida (from: Jelks
and Collopy 1987). . .... 51

3-4. Comparison of nesting densities and groundwater-well water
levels at Kissimmee Prairie survey area, 1984-1986 breeding
seasons. (a) Breeding pair densities as determined from aerial
fixed-strip width transect surveys. (b) Daily maximum water
levels from shallow well OS182 on Kissimmee Prairie. 61


xiii







3-5. Comparison of nesting densities and groundwater-well water
levels at Myakka River State Park survey area, 1984-1986
breeding seasons. (a) Breeding pair densities as determined
from aerial fixed-strip transect surveys. (b) Daily maximum
water levels from shallow well 19E on Sarasota County
Ringling-MacArthur Reserve. . 62

3-6. Comparison of nesting densities and groundwater-well water
levels at Webb WMA survey area, 1984-1986 breeding seasons.
(a) Breeding pair densities as determined from aerial fixed-
strip transect surveys. (b) Monthly water levels from
shallow well L-3209 near Webb WMA. . ... 63

3-7. Spatial distribution of Florida sandhill crane nests by 3 km
x 3 km grid cells observed during 8 systematic aerial transect
surveys of the Webb Wildlife Management Area and surrounding
lands, January-April 1985. No repeat sightings are
included . . ... 69

3-8. Spatial distribution of Florida sandhill crane nests by 3 km
x 3 km grid cells observed during 8 systematic aerial transect
surveys of Myakka River State Park and surrounding lands,
January-May 1985. No repeat sightings are included. 70

3-9. Preselected 3 km x 3 km quadrats surveyed for Florida
sandhill crane nests during 8 aerial surveys on Myakka River
State Park and surrounding lands, January-May 1985. Numbers
denote nests sighted . .... 71

3-10. Spatial distribution of Florida sandhill crane nests by 3 km
x 3 km grid cells observed during 7 systematic aerial
transects on the Kissimmee Prairie, Florida, January-May 1985.
No repeat sightings are included . .... .72

3-11. Preselected 3 km x 3 km quadrats surveyed for Florida sandhill
crane nests during 8 aerial surveys on Kissimmee Prairie,
January-May 1985. Numbers denote nests sighted. .... 73

3-12. Spatial distribution of Florida sandhill crane nests by 3 km
x 3 km grid cells observed during 10 systematic aerial
transect surveys of Myakka River State Park and surrounding
lands, January-May 1986. No repeat sightings are included 75

3-13. Spatial distribution of Florida sandhill crane nests by 3 km
x 3 km grid cells observed during 10 systematic aerial
transect surveys of Webb Wildlife Management Area and
surrounding lands, January-May 1986. No repeat sightings
are included . . ... 76

3-14. Spatial distribution of Florida sandhill crane nests by 3 km
x 3 km grid cells observed during 11 systematic aerial
transect surveys on the Kissimmee Prairie, Florida, January-
May 1986. No repeat sightings are included. .. 77


xiv







3-15. Size of wetland (ha) used by Florida sandhill cranes for
nesting during 1985 and 1986. (a) Myakka River State Park
and surrounding lands. (b) Kissimmee Prairie. (c) Webb
Wildlife Management Area and surrounding lands .. 100

4-1. Locations of 7 feeding concentration sites (white stars),
and 1 bait site (black star) where Florida sandhill cranes
were trapped and color-marked, Kissimmee Prairie, Florida,
July 1985 January 1986 . .. 120

4-2. Annual home range of AM1 as calculated by 3 different
methods: modified minimum convex (291 ha); minimum convex
(581 ha); and 50% (92ha) and 95% (1,133 ha) harmonic mean. 127

4-3. Annual home range of AF4 as calculated by 2 methods:
minimum convex (1,139 ha), and 50% (51 ha) and 95% (1,595 ha)
harmonic mean. ... . ... 128

4-4. Three-dimensional plot of annual home range for Florida
sandhill crane AM1, on the Kissimmee Prairie, Florida. The
number of locations was 111, and each grid square is 1 ha. 131

4-5. Annual home range (modified minimum convex method) of 4
radio-tagged Florida sandhill cranes on the Kissimmee
Prairie, Florida, October 1985 January 1987. Numerals
denote individuals .... . .... 134

4-6. Annual home range (modified minimum convex method) of
1 subadult male (SM1) and 1 unpaired adult male (AM3)
radio-tagged Florida sandhill cranes on the Kissimmee
Prairie, Florida, October 1985 November 1986 137

4-7. Diurnal habitat use by time of day for: (a) 4 paired adults
and 2 chicks; (b) 2 subadults and 1 unpaired adult.
Locations on the nest are not included ... 141

4-8. Seasonal diurnal habitat use for 4 paired adults and 2
chicks, October 1985-January 1987 (N=413). Locations on
the nest are not included. .. ... .. 142

4-9. Nonsocial Florida sandhill crane behavior (observations
without nonrelated cranes) by season for: (a) 3 families,
and (b) 2 breeding pairs .... 147

A-1. Map of Webb Wildlife Management Area (from: Florida Game
and Fresh Water Fish Commission leaflet 1987, with
additions. ... . 165

B-1. Map of Three Lakes Wildlife Management Area (from Florida
Game and Fresh Water Fish Commission leaflet 1987, with
additions) .. . 167

B-2. Map of proposed Three Lakes WMA/Prairie-Lakes State Preserve
addition . . . 168














Abstract of Dissertation Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy


FACTORS AFFECTING PRODUCTIVITY AND HABITAT USE OF
FLORIDA SANDHILL CRANES (Grus canadensis pratensis): AN
EVALUATION OF THREE AREAS IN CENTRAL FLORIDA FOR A NONMIGRATORY
POPULATION OF WHOOPING CRANES (Grus americana)


By

Mary Anne Bishop

August 1988

Chairman: Michael W. Collopy
Major Department: Forest Resources and Conservation
(Wildlife and Range Sciences)

Three areas in central Florida, identified as potential release

sites for a third flock of whooping cranes (Grus americana), were

evaluated and ranked as to their priority for reintroduction.

Potential reintroduction sites were ranked as follows: (1) Kissimmee

Prairie including Three Lakes Wildlife Management Area, Prairie-Lakes

State Preserve, and National Audubon Society Kissimmee Prairie

Sanctuary; (2) Webb Wildlife Management Area; and (3) Myakka River

State Park. Primary criteria used to evaluate each area included the

numbers and productivity of breeding Florida sandhill cranes (Grus

canadensis pratensis), and the land use status and trends for each

potential release site and its surrounding lands. In order to

determine the densities of breeding pairs by season and area,

systematic aerial transect surveys for nesting Florida sandhill cranes

were conducted from March through mid-May for 1984, and mid-January
xvi







through mid-May during 1985 and 1986. For 1986, surveys indicated the

highest densities on the Webb Wildlife Management Area (0.52

pairs/km2), followed by the Kissimmee Prairie (0.25 pairs/km2) and

Myakka River State Park (0.22 pairs/km2). Of the three proposed

release sites, the two in southwest Florida, Myakka River State Park

and Webb Wildlife Management Area, face increasing development

pressures surrounding their boundaries. On the Kissimmee Prairie,

relative isolation from major population centers and the presence of

large, undeveloped family-owned and public landholdings provide optimum

conditions for the reintroduction of whooping cranes. On the Kissimmee

Prairie, home range and habitat use was determined for 4 paired adults,

2 chicks, and 3 subadult radio-tagged cranes. Average annual home

range based on the modified-minimum area method was 1.83 + 1.03 km2

(SD) for the paired adults and chicks. Subadults did not maintain a

consistent home range area throughout the year. Long distance moves

(>5 km) usually were followed by temporary residence in an area.

Daytime habitat used most often by monitored cranes was improved

pasture (39-78%) followed by herbaceous emergent wetlands (15-47%).

Within their home range, Florida sandhill cranes used herbaceous

emergent wetlands in greater proportion than their availability.


xvii















CHAPTER I
INTRODUCTION



Justification



The Florida sandhill crane (Grus canadensis pratensis) is 1 of 6

subspecies of the sandhill crane and occurs from Okefenokee Swamp in

southeastern Georgia to the Florida Everglades. This nonmigratory

subspecies is estimated to have approximately 4,000 individuals

(Williams 1978, Logan and Nesbitt 1987). The Florida sandhill crane

currently is designated as a threatened species by the Florida Game and

Fresh Water Fish Commission (FGFWFC) (FGFWFC 1983), indicating that if

current trends continue it is likely to become endangered in the State

within the foreseeable future (Kale 1978). Although no systematic

census or monitoring of the Florida sandhill crane population has been

conducted across its range, the loss of habitat through wetland

drainage and developments coupled with a low reproductive rate are

considered to be the main factors contributing to the low population

numbers and a speculated slow population decline (Williams 1978).

Central Florida supports the greatest concentration of Florida

sandhill cranes (Walkinshaw 1976). Detailed information, however, is

lacking on the populations of cranes throughout this area. There are

no total population, breeding pair, or wintering greater sandhill crane

(Grus canadensis tabida) estimates for the region.

1








Before this study began, most of the available information on

Florida sandhill cranes in central Florida was from 2 studies of

reproductive success. Walkinshaw (1976, 1982, 1987, in press) provided

reproductive data for 1967-1987 on Florida sandhill cranes around the

Kissimmee Prairie, including Osceola, Polk, and Okeechobee counties.

Nest site characteristics, approximate laying dates, and hatch success

were determined for over 150 nests. From 1973-1979, Layne (1983)

monitored Florida sandhill cranes with young during summer and fall

road surveys in south central Florida, primarily Charlotte, DeSoto,

Glades, Hardee, Highlands, and Okeechobee counties.

In 1980, the FGFWFC proposed to the Whooping Crane Recovery Team

that the nonmigratory Florida sandhill crane be evaluated as a

potential foster parent to a third whooping crane (Grus americana)

population (FGFWFC 1981). Subsequently, several sites in central

Florida were identified for possible whooping crane reintroduction.

These sites were initially selected based on the availability of public

lands and their estimated populations of Florida sandhill cranes

(Nesbitt 1982).

The Whooping Crane Recovery Plan (1986) included, as part of its

primary goal, increasing the whooping crane population breeding in Wood

Buffalo National Park, Canada, and wintering in Aransas National

Wildlife Refuge, Texas, to 40 nesting pairs, and establishing at least

2 additional, disjunct populations each with 25 nesting pairs. The

first additional flock of whooping cranes was established in 1975,

using greater sandhill cranes nesting at Grays Lake National Wildlife

Refuge (NWR), Idaho as foster parents.








In cooperation with the Wildlife Research Bureau of the FGWFWC, I

began to evaluate the 3 most promising whooping crane release sites in

central Florida in fall 1983. These sites included Myakka River State

Park (SP), C.M. Webb Wildlife Management Area (WMA), and the Kissimmee

Prairie area, including Three Lakes WMA and the National Audubon

Society (NAS) Ordway-Whittell Kissimmee Prairie Sanctuary (Fig. 1-1).

This study was designed to complement the FGFWFC investigations on

cross-fostering and gentle-release reintroduction techniques being

conducted on the Paynes Prairie and Kanapaha Prairie in Alachua County,

Florida (Logan and Nesbitt 1987, Nesbitt in press).

In addition to the Florida crane studies, 2 additional potential

whooping crane release areas in eastern North America were evaluated

during the course of this study. The Ohio Cooperative Fish and

Wildlife Research Unit conducted work on greater sandhill cranes at

Seney NWR in upper peninsula Michigan and on the wintering grounds in

Florida (McMillen 1987). The Georgia Cooperative Fish and Wildlife

Research Unit studied the Florida sandhill cranes in Okefenokee Swamp

in Georgia (Bennett and Bennett 1987). In February 1988, all 3 studies

presented their results and recommendations to the U.S. Whooping Crane

Recovery Team in Orlando, Florida.



Objectives



This dissertation is a report of a study conducted in central

Florida from September 1983 through January 1987. The overall

objectives of this study were the following:


























KISSIMMEE PRAIRIE


C.M. WEBB WILDLIFE
MANAGEMENT AREA


Figure 1-1. Locations of 3 proposed whooping crane release sites
in central Florida.








1. Evaluate 3 sites (Kissimmee Prairie, Myakka River State Park,

and C.M. Webb Wildlife Management Area) as potential

reintroduction sites for whooping cranes.

a. Characterize the vegetation, land use status and trends for

each area.

b. Estimate the breeding population and annual recruitment of

the Florida sandhill cranes.

c. Determine factors influencing productivity on the 3 sites.

2. Determine habitat use by selected pairs of Florida sandhill

cranes residing on the Kissimmee Prairie.

a. Monitor the seasonal movements and social behavior.

b. Characterize the habitat and patterns of habitat use within

selected cranes' home ranges.















CHAPTER II
LAND USE STATUS AND TRENDS OF POTENTIAL RELEASE SITES



Introduction



Reintroduction, the act of reestablishing an extirpated species,

subspecies or ecotype in an area within its original geographic range

(Grieg 1979), is a conservation strategy that has been used for several

species of animals (Grieg 1979), including Mississippi sandhill cranes

(Grus canadensis pulla) and whooping cranes (Grus americana)

(Derrickson and Carpenter 1987). Reintroduction can be a particularly

useful strategy to reestablish species whose extinction in a particular

habitat were due to factors which have now been controlled (e.g. human

persecution, over-collecting, over-harvesting or habitat deterioration)

(Int. Union Conserv. Nat. Nat. Resour. 1987). While a reintroduction

plan superficially can be an appealing and dramatic conservation

strategy, its ultimate success depends on careful planning.

The International Union for the Conservation of Nature and Natural

Resources (IUCN) position statement on translocations (IUCN 1987)

outlines 4 steps in a reintroduction program. These include an

assessment study, a preparation phase, a release or introduction phase,

and a follow-up phase. The first step, an assessment study, should

include an analysis of factors that influenced the species original

decline. The analysis should include an assessment of sociological,

scientific, and ecological factors associated with reintroduction.
6








Land use patterns and trends are important components in assessing

current ecological conditions and predicting future scenarios for any

potential reintroduction. While public lands can be managed for

reintroduction, the surrounding private land use may determine whether

the reintroduced population can be sustained or expanded.

In 1980, the FGFWFC proposed to the Whooping Crane Recovery Team

that the Florida sandhill crane be evaluated as a potential foster

parent to a third, reintroduced whooping crane population. Following

preliminary survey work (Nesbitt 1982), in fall 1983 the 3 most

promising release sites were selected for further study: Myakka River

State Park (SP), C.M. Webb Wildlife Management Area (WMA), and the

Kissimmee Prairie area, including Three Lakes WMA and the National

Audubon Society (NAS) Ordway-Whittell Kissimmee Prairie Sanctuary (see

Fig. 1-1). These sites were initially selected based on the

availability of public lands and their estimated populations of Florida

sandhill cranes.

As part of an assessment of the suitability of reintroducing

whooping cranes in Florida, the objectives of this phase of the study

were to (1) characterize the land use patterns and status for the 3

proposed Florida whooping crane reintroduction sites, including

surrounding private lands, and (2) evaluate and rank their potential

for Florida sandhill crane population expansion as well as whooping

crane reintroduction.



Methods


A set of criteria was developed to evaluate land use status and

trends for each potential release site and surrounding private lands.








These criteria include acreage, ownership, management, public use,

access, potential threats, and the potential to support an expanding

population of Florida sandhill cranes and whooping cranes. Operational

management plans available for Three Lakes WMA (McCracken 1979), Myakka

River SP (Florida Dept. Nat. Resour. (FDNR) 1987), and C.M. Webb WMA

(FGFWFC 1982) outlined in most cases land use and vegetation types, as

well as the management status and trends for each area. For Three

Lakes WMA and Prairie-Lakes State Preserve, vegetation types were

digitized using Mark Hurd (1:24,000) aerial photographs and from

information provided in the Three Lakes WMA operational management plan

and ground truthing. Vegetation types on the Webb WMA were identified

from maps prepared by the Florida Department of Transportation (FDOT)

(FDOT 1978). Additionally, site managers were interviewed for recent

information on access and public usage.

Ownership of private lands were determined from the most recently

published plat directories and from county courthouse records. Trends

in private land use and potential threats were determined from on-site

visits, interviews with local sources, comprehensive regional and

county policy plans, estimates of population (Bur. Econ. Business Res.

1987) and from recent Mark Hurd (1:24,000) and county tax assessor

(1:4,800) aerial photographs.



Results



C.M. Webb Wildlife Management Area

The Webb Wildlife Management Area contains of 26,454 ha in

Charlotte County, Florida and lies in portions of Township 41S Ranges








24 and 25E, Township 42S Ranges 23, 24 and 25E. It is situated 8 km

southeast of Punta Gorda, 32 km north of Fort Myers, and 30 km from the

Gulf of Mexico. It extends approximately 14.5 km from north to south

and 21 km from east to west (Fig. 2-1).

The area is flat and is characterized by poorly-drained sandy

soils with either a sandy, organic-stained or a loamy subsoil (U.S.

Dept. Agric. 1984). Dominant vegetative communities (Fig. 2-2)

consists of 2 similar types: saw-palmetto (Serenoa repens) prairies

(44%), and pine flatwoods (28%), characterized by South Florida slash

pine (Pinus elliottii var. densa) and an understory of saw-palmetto and

wiregrasses (Aristida spp.). Freshwater marshes, wet prairies, and

intermittent ponds comprise 21% of the land area and are scattered

throughout the WMA (FDOT 1978), especially along the south and

southwesterly periphery. The most common vegetative cover in the

freshwater marshes includes sawgrass (Cladium jamaicense). Other

characteristic plants include pickerelweed (Pontederia cordata),

maidencane (Panicum hemitomon), arrowhead (Sagittaria lancifolia), and

spikerushes (Eleocharis spp.).

Annual rainfall averages approximately 126 cm on the Webb WMA

(U.S. Dept. Commerce 1984). Rainfall is unevenly distributed

throughout the year with a dry season from November to April and a wet

season from May to October. Over 70% of the rainfall occurs during the

wet season. Tropical storms usually occur from August to October and

often bring flooding conditions to the area.

The Webb WMA was acquired in 1941 by the FGFWFC for wildlife

management purposes. At present, all but 1,063 ha is under the control

of the FGFWFC. In the northeast corner, 518 ha have been leased to the






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NYAKKA RIVER SP


HAS KISSINMEE SANCTUARY


marsh & wet prairie


LIJ


pine flatwoods


dry prairie


other


Figure 2-2. Habitat composition for proposed whooping crane release
sites in central Florida: Webb Wildlife Management Area (WMA),
26,455 ha; Myakka River State Park (SP), 11,690 ha; National Audubon
Society (NAS) Ordway-Whittell Kissimmee Prairie Sanctuary, 2,955 ha;
and Three Lakes Wildlife Management Area (WMA) and Prairie-Lakes
State Preserve, 11,920 ha, but excluding the 7,150 ha north of the
Florida Turnpike.


THREE LAKES WMA & PRAIRIE LAKES SP


WEBB WMA








Boy Scouts of America for a scout camp. In the northwest corner,

358 ha of improved pasture is leased to the City of Punta Gorda for a

waste water disposal facility (Appendix A). In the southeast corner,

7 ha is leased as a permanent easement for a television broadcasting

tower. Additionally, there are 18 in-holdings, accounting for 180 ha.

The current operational management plan (FGFWFC 1982) proposes

that 2 tracts on the Webb WMA be leased or sold for commercial value.

These include 463 ha between US 41 and 1-75, and 10 ha lying within the

1-75 interchange at Tuckers Grade (Appendix A).

Since its acquisition as a state wildlife management area, the

primary management emphasis has been on bobwhite quail (Colinus

virginianus floridanus) through habitat manipulation. Quail feeders

have been used to supplement natural food supplies and are frequently

used by the Florida sandhill cranes. As part of a 5 year study on

quail, 350 feeders are serviced year-round (L. Campbell, FGFWFC, pers.

commun., 1987).

Prescribed burning and cattle grazing have been the major

management tools to maintain ground vegetation in early succession.

Semi-annual burning of 65-ha blocks of pine flatwoods and saw-palmetto

prairies is conducted between November and the first week in March.

Cattle are grazed by lease agreement with private individuals on all

but 3,100 ha reserved for bird dog field trials (FGFWFC 1982). There

are two 6,480-ha pastures with 1 and 4 cross fences, respectively, and

one 4450-ha pasture with 1 cross fence. All interior fences are 4-

strand barbed wire (L. Campbell, pers. common., 1987).

In recent years, historic sheetflow patterns have been altered as

a result of the dikes and roads associated with peripheral ranchette








type developments. Sheetflow has become concentrated toward culvert

outlets, bridges, and creeks. On the west side of the Webb WMA,

drainage has been accelerated, whereas on the south side, flooding is

caused by dikes on private property (FGFWFC 1982, Johnson Engineering

Inc. 1983).

In 1983, a water management plan for the Webb WMA (Johnson

Engineering Inc. 1983) included proposed water control structures to

alleviate the seasonal extremes in the hydroperiod and the uneven

peripheral outflow. Since then water control structures have been

installed at 11 locations on the management area. These structures

allow surface water flow to be directed into specific wetland areas and

at the same time create upstream impoundment areas. Another 5-7

structures will be installed in the future as part of the hydrological

plan (L. Campbell, pers. common., 1987).

In 1987 an agreement was reached between the Department of

Corrections and the FGFWFC to install 5 or 6 shallow production wells

as a potable supply source for a new correctional facility 2.5 km south

of the WMA. Plans are underway to monitor the effect of these

withdrawals on water levels and the existing vegetative habitat.

Currently, 4,450 ha on the west side of the Webb WMA is open year-

round for vehicle access and recreation during daylight hours (Appendix

A). The primary non-hunting recreational activities have been fishing

and frogging and use of the shooting range. Non-hunting man-day use in

1986 totaled approximately 25,000 per year (L. Campbell, pers. commun.,

1987).

The hunting season on the Webb WMA begins at the end of October

with a 9-day deer and hog hunt. Typically quail and small game hunting








is permitted from November 14 through mid-February. Although there

have been attempts to improve waterfowl habitat on the Webb WMA,

waterfowl hunting is virtually nonexistent. Instead, most waterfowl

hunting occurs in Charlotte Harbor (Fig. 2-1), west of the WMA. With

the exception of the deer and hog hunt, and the first 6 days of the

quail season, hunting is allowed only Wednesday, Thursday, Saturday,

and Sunday. During the 1986-87 hunting season, approximately 4,288

people participated in management area hunts. Vehicles are allowed

throughout the Webb WMA during the hunting season with the exception of

2 walk-in areas on the north and south end (Appendix A).

The perimeter of the Webb WMA is fenced with woven "hog" wire.

Public access to the Webb WMA is controlled through the Tucker Grade

entrance. Two exceptions are the "40-acre pond" on the north side

which is open during the non-hunting season, and the bird dog field

trial grounds (Appendix A) which are open from October through the end

of January. Three-wheeled vehicles and motorcycles are prohibited from

all parts of the Webb WMA.



Webb Wildlife Management Area Surrounding Land Use and Potential
Threats

Contiguous to the Webb WMA on the east side are 2 large private

landholdings (Fig. 2-1) that are managed for timber, cattle, and

wildlife. Telegraph Swamp, an extensive cypress (Taxodium distichum)

swamp, cuts through both of these properties. The 2,343-ha Hall Ranch

to the northeast is family-owned and operated. The large 36,450-ha

Babcock Ranch to the east extends to the county line and south into Lee

County. This ranch is incorporated but is owned by one family. Both

the Hall and Babcock ranches lease hunting rights to private








individuals. Nesting Florida sandhill cranes have been observed on

both of these areas.

On the southwest side of the Webb WMA there are still some 7

undeveloped parcels ranging in size from 259 ha (1 section) to 1,495

ha, including 2 that adjoin the Webb WMA. Cranes are known to nest or

use at least 4 of these parcels on a regular basis. Given the

proximity to 1-75, US 41, and Ft. Myers, as well as the construction of

a new county jail in the area, development will probably continue into

the future.

While not contiguous, there are 2 other large inland landholdings

within 37 km of the Webb WMA that support crane populations. These

include the approximately 121,450-ha family-owned and operated Lykes

Brothers Fisheating Creek Ranch, 19 km to the northeast and Myakka

River SP-Sarasota County Ringling-MacArthur Reserve, approximately

37 km to the northwest (Fig. 1-1).

To the north, south, and west the Webb WMA is surrounded by

platted developed and undeveloped lands and small (2-4 ha) tracts.

These developments are the result of both a significant population

growth on and near the southwest coast of Florida since 1950 and

accompanying land speculation. Between 1980 and 1986, human

populations in Charlotte and the adjoining Lee and Sarasota counties

increased by 42%, 35%, and 21%, respectively (Table 2-1) (Bur. Econ.

Business Res. 1987). While these populations are expected to continue

growing, the growth rates seen in the past will likely not be as great

(Southwest Florida Reg. Planning Counc. 1987).

Large, platted, undeveloped lands that have minimum street and

drainage facilities are concentrated in the cities of Cape Coral in Lee








Table 2-1. Human population growth and
selected areas in central Florida.


forecasts by county for


County 1980a 1986a 1990ab 2000a,b


Charlotte 58,460 82,968 104,600 155,000

Lee 205,266 277,375 344,000 494,700

Manatee 148,445 175,893 201,500 256,000

Sarasota 202,251 244,634 286,600 382,700

DeSoto 19,039 22,287 26,100 33,800

Okeechobee 20,264 26,564 32,200 43,800

Osceola 49,287 82,554 111,900 174,900


a Bureau of
b Estimates
migration


Economic and Business Research, 1987.
based on high human growth projections similar to large
levels of 1970-1975.








County, North Port in Sarasota County, and in unincorporated coastal

areas of Lee and Charlotte counties. Although large-scale speculation

has slowed considerably since the 1960's, large development projects

continue to be approved. In 1987 Charlotte County approved the 728-ha

Seminole Trail development for 5,600 people. This development is

contiguous to the north side of Webb WMA, across from the "40-acre

pond" (Appendix A) (L. Campbell, pers. commun., 1987).

Development for agricultural purposes is increasing as well as for

human populations. As a result of 4 winter freezes between 1983 and

1986 which damaged or killed groves in central Florida, citrus

production is shifting to southwest Florida at a significant rate.

Most of this increase, however, is occurring to the east and south of

Charlotte County. In Charlotte County, citrus production is

concentrated north of CR 74. As of 1986, approximately 3,550 ha were

in commercial groves (Florida Crop Livestock Rep. Serv. 1986).

In addition to development pressures and increased conversion to

citrus groves, there are 2 other potential threats to cranes in this

area: aerial hazards and tropical storms. Three north-south

electrical transmission lines cut through the study area, (Fig. 2-1),

including 2 adjacent 230 kV lines that diagonally cross the Webb WMA,

and another 230 kV line that runs along US 41. Additionally, there are

electrical distribution lines, especially in the adjoining and nearby

developed areas. Broadcasting towers also exist in the area, including

3 television towers located in the southeast corner and 2 smaller

towers in the southwest corner of the WMA (Fig. 2-1).

Southwest Florida has been identified by the National Weather

Service as one of the most hurricane-vulnerable areas of the United








States. Ft. Myers, 32 km to the south of the WMA, has a probability of

hurricane-force winds (>119 km/h) occurring every 12 years (Fernald and

Patton 1985). Although the Webb WMA lies at least 30 km from the Gulf

of Mexico, high winds and water that accompany hurricanes could

endanger and/or displace cranes.



Myakka River State Park

Myakka River State Park is Florida's largest state park and

contains 11,690 ha in Manatee and Sarasota counties (Fig. 2-3),

including portions in Township 37S Ranges 20, 21E, Township 38S, Ranges

20, 21, 22E, and Township 39S Range 22E. The park is situated 27 km

east of Sarasota, 48 km southeast of Bradenton, and 17 km from the Gulf

of Mexico.

Similar to the Webb WMA, Myakka River SP is relatively flat and is

characterized by poorly-drained sandy soils with either sandy, dark-

colored or loamy subsoils (U.S. Dept. Agric. 1983). Dominant

vegetation communities (Fig. 2-2) are broad saw-palmetto prairie

(>50%), and slash pine flatwoods (15%). Freshwater marshes, wet

prairies, and sloughs comprise approximately 25% of the land. The

Myakka River flows through the park for 13 km, and forms the western

boundary throughout most of the park (Fig. 2-3). Major marshes are

found primarily along the river and its 2 large lakes, Upper and Lower

Myakka (FDNR 1987).

Annual rainfall averages approximately 144 cm on Myakka River SP

(U.S. Dept. Commerce 1984). Between 70-80% of the rainfall occurs

during the wet season (May-October), and much of the park is flooded















































Figure 2-3. Map of Myakka River State Park and surrounding lands.








during these months. Like the Webb WMA, tropical storms usually occur

in the months of August through October.

Myakka River SP was initially opened to the public in 1941. The

main goal of the park is to preserve and maintain a natural setting

while permitting a full program of compatible recreational activities,

both active and passive. It is the philosophy and policy of the

Florida Park Service to manage all state parks as closely as possible

to their appearance when the first Europeans arrived. Consumptive

uses, therefore, including hunting, livestock grazing, and timber

removal are not permitted (FDNR 1987).

There are 2 major management zones in the park: development and

natural. The development zone includes an interpretive center, a food

and boat concession on Upper Myakka Lake, a tram tour, campgrounds, and

cabins. These facilities are all located on the north side of SR 72,

and are confined to a small corridor along Myakka River and Upper

Myakka Lake.

The natural management zone includes 3 areas: a wilderness

preserve, river zone, and all other natural areas of the park. The

wilderness preserve is the 3,036-ha area south of SR 72 (Fig. 2-3).

This area is managed in the same manner as the non-river natural zone;

however, visitation is restricted to 30 persons per day on foot and 12

canoes per day. The river zone includes Myakka River, Upper Myakka

Lake, and Lower Myakka Lake. Water levels and precipitation are

monitored for this area. Water management emphasizes the treatment and

control of exotic wetland invaders, in particular, Hydrilla

verticillata.








The non-river natural area and the wilderness preserve both are

monitored and managed to resemble as closely as possible "original

natural Florida." From 1934-1970 natural fires were suppressed and

controlled burning was not allowed within the park. During these years

there was an accumulation of woody species in historically herbaceous

areas.

Beginning in 1971, controlled burning was used to recreate the

"original natural Florida" in the non-river natural area. Fire-

dependent communities, such as the dry saw-palmetto prairie, the

flatwoods, and marshes are now typically burned at 1-4 year intervals,

depending on their successional state. Late-spring and summer burns

are prescribed for flatwoods and saw-palmetto prairie to approximate

natural lightning-set fires. Freshwater marsh, such as those along the

river, are burned in late winter and early spring (FDNR 1987).

Habitat destruction by feral hogs (Sus scrofa) has become a

management problem on Myakka River SP. The overpopulation of hogs is

due to both the absence of natural predators and a lack of hunting

pressure. Beginning in May 1986, a trapper was contracted to remove

hogs from the park using traps and dogs. During the first year, 668

hogs were removed and a 1200-hog limit was set for 1987 (Myakka River

SP files).

Short-term flooding along the river and the Upper and Lower Lakes

is the major hydrological management problem within the park. The 2

existing subdivisions on the northwest side of the park direct their

drainage into Myakka River causing a rapid rise in river and lake

levels following heavy precipitation. The diking of both Tatum

Sawgrass, a 1,740-ha marshy depression adjacent to the north of the








park, and Vanderipe Slough just south of Upper Myakka Lake also has

changed the historical hydroperiod in the marshes and lowlands adjacent

to the lakes and river. The change in hydroperiod has permitted

hardwoods, primarily Carolina ash (Fraxinus caroliniana) to invade

marshes and has increased the hammocks that border the river zone (FDNR

1987).

In other parts of the park, sheet flow has been impeded by SR 72

and all-weather roads built to permit park and utility line personnel

access during the wet season. At the same time, some fire lines serve

as artificial channels and hasten drainage from other areas. Fire

lines tend to hold water on the sites and will sometimes impede control

burns. Currently, these fire lines are being allowed to become

overgrown to alleviate the problem (FDNR 1987).

Myakka River SP is open year-round to the public. During FY 1987,

there were 254,066 visitors, 20% of whom are from states other than

Florida. Vehicular access to Myakka River State Park is primarily

through one entrance on SR 72. On weekends, a north entrance on CR 780

is open. Within the park, there is a north-south road open to the

public. With the exception of 60 km of backpacking trails, 25 km of

horseback riding trails, and the wilderness preserve on the south side

of SR 72, all recreational activities (picnicking, camping, fishing,

boating, bicycling, and cabins) are concentrated along this one road.



Myakka River State Park Surrounding Land Use and Potential Threats

Immediately bordering the park to the south and portions of the

west are large tracts of undeveloped and ranchlands. In 1984, 6,500 ha

of the 13,200-ha Ringling-MacArthur tract was purchased by the County








of Sarasota as a potable water supply source and additionally as a

recreation and open space area (Sarasota County Ordinance No. 82-94).

These lands were subsequently designated the Sarasota County Ringling-

MacArthur Reserve. Currently, there are negotiations to purchase an

additional 3,300 ha for a total of 9,800 ha in the reserve (Fig. 2-3)

(J. Lincer, Sarasota County, pers. common., 1988). The original

13,200-ha tract is primarily pine flatwoods (42%), saw-palmetto prairie

(16%), and wetlands (29%) (Lincer 1982).

Management on the Sarasota County Ringling-MacArthur Reserve will

be primarily for water, recreation, and wildlife, and must be

compatible with the management on Myakka River SP (Sarasota County

Resolution No. 82-200). There is a long-term monitoring program of the

surficial and subterranean water regimes aimed at assessing the impacts

on and preserving the integrity of the wetlands on the tract. A

significant percentage of the reserve will be designated in the

preservation category to protect the flora, wildlife, and wetlands from

any unnatural changes. The interim burning plan is similar to Myakka

River SP, and focuses on May and June controlled burns. Recreation

uses considered priority are those that are resource-based,

nonconsumptive, and ecologically benign, with a special emphasis on

environmental education. Currently the reserve is closed to the

public. It will not be open until support facilities, including a main

access road, are constructed (J. Lincer, pers. commun, 1987).

North of the Ringling-MacArthur Reserve, the remaining 3,240 ha of

the original Ringling-MacArthur tract continues to be owned by a

private foundation (Fig. 2-3). Through an agreement with Sarasota

County, all of the development rights are suspended on this portion








until 1994, and the county permanently retains all rights to

intermediate and deep waters, but not surficial water. The foundation

leases hunting and grazing rights to a private sporting club (J.

Lincer, pers. common., 1987).

Adjoining both the Ringling-MacArthur Reserve and Myakka River SP

to the southeast and southwest are family-owned and operated ranches

managed primarily for cattle with some timber and citrus production.

Large portions of these lands were cleared several years ago for

improved pasture. A 2,445-ha ranch to the southwest of the park was

recently purchased by Sarasota County for a landfill (Fig. 2-3). Only

a small portion of the parcel will be used at one time for a landfill;

and the rest of the property will be left as is (R. Klier, Sarasota

County, pers. common., 1987).

Along the irregularly-shaped northeast border of the park, small

(<800 ha) ranch operations are most common. Recently, however, a

850-ha parcel adjoining the park was platted for ranchettes. To the

north and northwest, small tracts and 2 established subdivisions also

border the park.

Like the other coastal counties in southwest Florida, Sarasota has

and will continue to experience a relatively high growth rate (Table

2-1). Currently the policy of Sarasota County is to contain high-

density development to the west of 1-75 (Sarasota County 1981). Two

and 4-ha tract developments, however, are allowed in rural-zoned areas

and are a growing trend along CR 780 and other areas east of 1-75

interchanges. Already bordering a portion of the Ringling-MacArthur

Reserve is North Port, a sparsely settled community that includes

81,700 undeveloped lots and 1.2-ha tracts (Fig. 2-3). While its








population, including winter residents, is estimated at only 13,000

people, over 38,000 people are predicted by the year 2000 (Bur. Econ.

Business Res. 1987).

Aside from development pressures in rural areas near Sarasota,

another environmental threat in this area is the phosphate industry.

Seven phosphate companies own large landholdings in eastern Manatee

County for future mining. Thus far, these lands are used primarily for

agriculture (Manatee County 1986). If phosphate mining is initiated in

this area, it would not only eliminate wetland habitat, but could have

negative effects on the Myakka River watershed (FDNR 1987).

Two other potential threats to cranes in this study area are

aerial hazards and hurricanes. Aerial hazards include 4 electrical

transmission lines both near and in the park (Fig. 2-3). Two adjacent

138 kV and 230 kV lines cut diagonally across the park and into the

Ringling-MacArthur Reserve. The other 2 transmission lines include an

230 kV east-west line along the south end of the Ringling-MacArthur

Reserve, and a 230 kV north-south line that runs west of the park.

There are relatively few transmitting towers in the area (Fig. 2-3).

The westernmost part of Myakka River SP lies 17 km from the Gulf of

Mexico. As with the Webb WMA, a hurricane could cause substantial

flooding in the area and displace cranes.



Three Lakes Wildlife Management Area

Three Lakes Wildlife Management Area consists of approximately

19,100 ha in south central Osceola County and includes portions of

Township 29S Ranges 32 and 33E, Township 30S Ranges 31 and 32E,

Township 31S Ranges 31 and 32E. It is situated approximately 40 km








from St. Cloud and over 55 km from the Atlantic Ocean. Three Lakes WMA

borders Lakes Jackson, Marian, and Kissimmee. The Florida Turnpike and

CR 523 divide the property into 3, approximately equal, parts.

Prairie-Lakes State Preserve also divides the area (Figs. 2-4, Appendix

B). Of the total acreage, approximately 7,150 ha lie north of the

Florida Turnpike, and approximately 12,000 ha lie south of the

Turnpike.

Three Lakes WMA is flat and is characterized by poorly drained

sandy soils. Dominant vegetation cover on the 7,150-ha area north of

the Florida turnpike includes cypress (Taxodium spp.) strand swamps and

domes (19%) and slash (Pinus elliottii) and longleaf pine (Pinus

palustris) flatwoods (72%). Suitable crane habitat on Three Lakes WMA

lies primarily south of the Turnpike, where broad saw-palmetto prairie

(55%) and wet prairie and freshwater wetlands (29%) provide the major

vegetative cover for this 12,000-ha area (Fig. 2-2). Long-term

rainfall for Three Lakes WMA averages 131 cm per year (South Florida

Water Manage. District files). Between 70-80% of the rainfall occurs

during the wet season (May through October).

Three Lakes WMA was purchased by the State of Florida in 1974

under the Environmentally Endangered Lands Program. The major

objective of the purchase was to preserve and protect the area and its

endangered or threatened fauna and flora for the present and future

benefit of Floridians. Management responsibility for the original

purchase was divided between the FGFWFC (Three Lakes WMA) and the FDNR

(Prairie-Lakes State Preserve). The management policy of the FGFWFC

for Three Lakes WMA is to protect and enhance the land, wildlife, and

fisheries values, and to manage the land for compatible outdoor






27






ii- fit ift


(8,425 ha)

THREE KES WILDLIFE
S.MANA. G ENT AREA
-(19,07 hMO.
SPR RIE LAKES ...
STA PRESERVE \.l i
332 h.)





(24.800 ha)

I ~r l


1110.111 VI 1 11I::

MI. Ht. AIt
FAIR r. l..;;A





-rini -. -, -* -rs ''^ -. ---- ----
Will s I



(3,300 ha) ADB
~ 1 111 II\



(43.300 ha) ql AUDUBON
SANCTUARY
S1(2,955 ha)

1 7 km
scale fort Arm


Figure 2-4. Map of Kissiimee Prairie study area including Three
Lakes Wildlife Management Area, Prairie-Lakes State Preserve and
National Audubon Society Ordway-Whittell Kissimmee Prairie
Sanctuary. All Florida Game and Fresh Water Fish Commission
Wildlife Management Areas are stippled.








recreational activities (McCracken 1979). Total acreage on Three Lakes

WMA was increased in 1986 when FGFWFC acquired from the U.S. Federal

Government an additional 780 ha along the extreme northeast WMA border.

The Federal Government retained ownership on 750 ha of adjacent lands.

In 1986, the Florida Natural Areas Inventory submitted a proposal

to the State of Florida's Conservation and Recreation Lands Program

(C.A.R.L.) for the acquisition of approximately 22,400 ha as an

addition to Three Lakes WMA and Prairie-Lakes State Preserve (Appendix

B). Since then the proposal and a project design for 20,800 ha have

been reviewed and approved by the C.A.R.L. Committee. At the June 1988

C.A.R.L. meeting, the Three Lakes WMA/Prairie-Lakes State Preserve

addition was ranked 23rd on the C.A.R.L. acquisition list for 1988.

The timing of acquisition will now depend on both this ranking and the

availability of funds.

The proposed Three Lakes WMA/Prairie-Lakes State Preserve Addition

represents the most extensive less-than-fee-simple acquisition

procedure ever used in a C.A.R.L. project design. Only 890 ha of the

20,800 ha are being recommended for fee-simple acquisition. These

include the private lands bordering Lake Jackson and the north side of

Lake Marian. Conservation easements or owner contract agreements are

being recommended for the 2 largest parcels: the 4,000-ha Lucky L

Ranch, north of CR 523, and the 12,100-ha Adams Ranch, south of Lake

Marian to SR60. Access easements, drainage easements, and conservation

easements are recommended for the remaining private lands (FDNR 1988).

Predominant natural communities on the proposed addition are dry

saw palmetto prairie, mesic flatwoods and prairie hammock. Much of the

land has been altered for grazing purposes. The principal reason for








the proposed addition is to assure increased protection for native

wildlife species, particularly birds such as sandhill cranes and bald

eagles (Haliaeetus leucocephalus) that require extensive areas of

habitat to maintain viable populations (Jackson 1986).



Management on Three Lakes Wildlife Management Area

Until recently, cattle grazing and controlled winter burns on a 3-

year rotation were the major management tools for maintaining the dry

and wet prairies and the pine flatwoods habitats on Three Lakes WMA.

Cattle grazing was discontinued indefinitely in 1986 on all but the

Kissimmee River portion. State smoke management regulations requiring

early "fire out" times, coupled with a shortened burn season due to

conflicts with the hunting season, have resulted in fewer hectares

burned per year than scheduled. In September 1987, a new experimental

burn program was implemented using faster, helicopter-initiated fires.

Prior to its acquisition by the State, significant ditching and

canal work was done on Three Lakes WMA and the surrounding areas to

provide improved grazing land for cattle and for flood control. The

primary result of the modified drainage has been a shortened

hydroperiod. A hydrological plan to restore some of the historical

water regime has been written for Three Lakes WMA (McElroy 1977); to

date, however, there has been no money appropriated to implement the

plan.

Currently, Three Lakes WMA is open year-round to the public. The

primary recreational activity has been hunting with deer, small game,

and spring turkey seasons spanning the months of October through mid-

April. Deer hunting, the most popular sport, supported almost 16,000








man-days in 1986. There is a minimum of waterfowl hunting on Lake

Jackson in Three Lakes WMA. While estimates of man-days are not

available, waterfowl hunting on Lake Kissimmee is popular during the

45-day season (F. Johnson, FGFWFC, pers. common., 1988).

The perimeter of Three Lakes WMA is fenced with a 4-strand fence.

Public access to Three Lakes WMA is limited to 3 roads: 1 for each

major section (Appendix B). The 700-ha portion of Three Lakes WMA

along the Kissimmee River (Fig. 2-4) has no public access. Except

during the small game season, vehicles are permitted only on named or

numbered roads. Public camping facilities have not been developed on

Three Lakes WMA, and primitive camping is allowed in designated areas

only during the hunting season.



Prairie-Lakes State Preserve

Prairie-Lakes State Preserve lies between the northern and

southern portions of Three Lakes WMA (Figs. 2-4, Appendix B). In

keeping with the FDNR policy mentioned earlier for Myakka River SP,

this 3,300-ha preserve is managed to resemble its appearance when the

Europeans first arrived. Consumptive uses, including hunting,

livestock grazing and timber removal, are not permitted.

The 3 primary habitat types on the Preserve are dry prairie (65%),

freshwater marsh (11%) and upland hardwoods (16%) (Fig. 2-2).

Prescribed burning on a 1-3 year rotation is the primary management

strategy for preserving the freshwater marsh and dry prairie

communities. Similar to Three Lakes WMA, Prairie-Lakes State Preserve

has suffered from insufficient burning because of logistical problems,

resulting in rank vegetation in many areas. From 1983 through 1985, an








average of only 214 ha was burned per year. In November 1986, an

arson-instigated fire burned almost 900 ha in the area west of Lake

Jackson. Previous to this incident, this area had not been burned in

almost 7 years (Prairie-Lakes State Preserve files).

Prairie-Lakes State Preserve is open to the public year-round

during daylight hours. Fishing on Lake Jackson is the major

recreational use; hiking, nature study, and picnicking are also

permitted. There are no developed camping facilities. Public use of

Prairie-Lakes State Preserve has been relatively low. For FY 1985-1986

and 1986-1987, an estimated 6,079 and 3,872 people, respectively, used

the Preserve (Prairie-Lakes State Preserve files). Public access is

confined to one road running through the eastern portion of the

Preserve, from CR 523 to Lake Jackson. The western portion of the

Preserve has been designated a wilderness preserve. No vehicular

access by the public is allowed in this area (S. Graf, FDNR, pers.

commun., 1988)



National Audubon Society Kissimmee Prairie Sanctuary

Located in Okeechobee County approximately 10 km southeast from

the southernmost portion of Three Lakes WMA, the National Audubon

Society's Ordway-Whittell Kissimmee Prairie Sanctuary comprises

approximately 2,955 ha (Fig. 2-4). An initial purchase of 2,330 ha was

completed in 1980, and since then 624 ha along the southern end has

been acquired.

The sanctuary is located at the head of one of the Kissimmee

tributary watersheds (Seven Mile Slough) in an area where there has

been little water management activity. Water regimes on the site are








still quite natural and the area is generally wetter than other parts

of the prairie. Over 50% of the property is wet prairie or freshwater

marsh; another 37% is dry prairie (Fig. 2-2) (NAS files).

The primary purpose of the Kissimmee Prairie Sanctuary is the

preservation of natural areas and their associated wildlife species.

Public education and research also are management goals for the

Sanctuary, although both have been on a small scale. Prescribed winter

burns have been the management tool used to maintain the prairie

community. Cattle grazing is not permitted on the Sanctuary.

The Sanctuary is open to the public by appointment only. There

are no public roads accessing the property. In the long-term, there

are plans to build a visitor's center on the property and upgrade

existing roads for public access.



Surrounding Lands and Potential Threats to Three Lakes WMA/Prairie-
Lakes State Preserve and Kissimmee Prairie Sanctuary

The majority of the study area includes large (>2,700 ha) family-

owned and operated ranches (Table 2-2). Four of the largest ranches in

the area share borders with Three Lakes WMA: Adams Ranch (12,100 ha),

Latt-Maxcy (42,500+ ha), Bronson (3,100 ha), and Lucky L (4,000 ha).

Private ranches are managed for cattle, sod farming, and wildlife.

Citrus is of minor importance in the area, as the land is generally too

low to be considered prime citrus land. Much of the native rangeland

was converted to improved pasture since the 1960's. In Okeechobee

County for example, 20% (16,200 ha) of approximately 81,000 ha of

native rangeland was converted to improved pasture between 1960-1969.

During 1970-1979, an additional 14,200 ha was converted to improved

pasture (Okeechobee County Soil Conserv. Serv. files). Since then, low









Table 2-2. Approximate size (ha) of large private and public
landholdings on and near the Kissimmee Prairie, Florida.
Starred ranches border Three Lakes Wildlife Management Area.


Private Ranches Size

Adams Lake Marian 12,100

Latt-Maxcy El Maximo* 42,500

Bronson

Three Lakes* 3,100

Kenansville 5,600

Lucky L* 4,000

Overstreet* 2,700

Campbell Escape 2,800

Leroy Bass 5,600

Hayman 711 3,800


Public Lands

Three Lakes WMA 19,073

Prairie-Lakes SP 3,300

NAS Kissimmee Prairie Sanctuary 2,955

Kicco WMA 3,100

Bull Creek WMA 8,425

Upper St. Johns River WMA 24,800

Avon Park Bombing Range 43,300

Total Public Lands 104,953








beef prices and the increased housing demand in other parts of Florida

has made sod-farming of pastureland an increasingly important economic

activity and has increased conversion pressures on the remaining native

habitat.

Wildlife is an important economic activity for the private ranches

that lease hunting rights to private individuals and clubs. Currently,

however, many of the larger ranch owners (Adams, Latt-Maxcy, Campbell,

and Leroy Bass) only allow family and friends to hunt on their

properties. Most ranch owners take an active interest in wildlife,

often planting food plots and maintaining feeders for quail, turkey,

and deer.

Large areas in and around the study site are public lands (Fig.

2-4). On the east side of the study area, the St. Johns River Water

Management District (SJRWMD) is a major landholder, both along and near

the St. Johns River. With monies from the "Save Our Rivers Act", the

District has recently acquired 9,000 ha in the river floodplain

immediately north of SR 60, and 6,000 ha of Ft. Drum Swamp to the south

as part of a restoration program. These lands form the headwaters of

the St. Johns River and were once a broad, expansive marsh. Over the

years, thousands of hectares within the floodplain were converted to

agriculture through extensive systems of canals and levees.

The majority of the public lands in this portion of the St. Johns

River have been designated as 3 marsh conservation areas. Their

purpose is for water conservation and temporary storage of stormwater

before being discharged into adjacent stormwater storage areas. Over

the next 5 years, agricultural lands currently used for pasture and row








crops will be reflooded, and in some areas, should become a herbaceous

or shrubby marsh (SJRWMD 1983, 1987).

While water management is the primary purpose of the public lands

held by the District, secondary purposes include the protection and

improvement of fish and wildlife values and public recreation (Houder

1987). Currently, a continuous 30 km stretch along the St. Johns River

and floodplain between SR 60 and US 192 are managed through an

agreement with the FGFWFC as the 24,800-ha Upper St. Johns River Marsh

Type II Wildlife Management Area (Fig. 2-4). The Type II designation

means that all management activities, including hunting permits, are

handled through the Water Management District.

Access to the Upper St. Johns WMA is almost exclusively by boat.

The area is open year-round for fishing and frogging. Hunting season

is generally October through mid-April and includes deer, small game,

and spring turkey hunts; no trapping is allowed.

Northeast of Three Lakes WMA, the Bull Creek WMA is also owned by

St. Johns River Water Management District (Fig. 2-4). This WMA is

managed directly by the FGFWFC and is operated in a manner similar to

Three Lakes WMA. Prescribed, rotational, winter burns are the major

habitat management tool, and cattle grazing is excluded on the area.

Hunting season is late September through mid-April and includes deer,

wild hog, small game, and spring turkey hunts; no trapping is allowed.

Public access is limited to one entrance south of US 192.

On the southwest side of the study area, the Kissimmee River is

the site of an extensive land acquisition program of the South Florida

Water Management District (SFWMD), aimed at habitat and hydroperiod

restoration. During the 1960's, the originally meandering 157-km








Kissimmee River was channelized by the U.S. Army Corps of Engineers to

facilitate flood control. As a result of the canal, approximately

81,000 ha of river marsh and other wetlands were lost, groundwater

levels were lowered, and water quality in the river was adversely

affected (Florida Dept. Environ. Regulation (FDER) 1987).

Since 1973, restoration of the Kissimmee River has been studied.

In 1984, the SFWMD began a restoration demonstration project along 19

km of the northern reaches of the river to test methods of

reestablishing the natural water regime in the river valley. Land

acquisition is a major necessity in river restoration. Total

restoration will require the acquisition of over 20,200 ha of original

floodplain (FDER 1987).

In addition to the southernmost portion of Three Lakes WMA, there

are 2 large public landholdings on the river. In 1985, 3,100 ha on the

west side of the river, across from the southern extension of Three

Lakes WMA, were acquired by SFWMD through the "Save Our Rivers" funds.

In addition to water management by the district, these lands will be

managed for wildlife by FGFWFC as the Kicco Wildlife Management Area

(Fig. 2-4). Management objectives of the FGFWFC, including a decision

on public access for hunting, have yet to be finalized for this area

(B. Millsap, FGFWFC, pers. commun., 1987).

Adjoining Kicco WMA is the U.S. Air Force's Avon Park Bombing

Range, an extensive 43,300-ha area (Fig. 2-4). In additional to its

use as a bombing range, Avon Park is managed for cattle, timber, and

public recreational use, including hunting. It supports one of the

state's largest range management programs on a public property with

over 37,550 ha leased for grazing (G. Tanner, Univ. Florida, pers.








commun., 1988). Avon Park Bombing Range is estimated to have a crane

population of 30 pairs and was initially considered as a potential

reintroduction site for whooping cranes (Nesbitt 1982).

The Kissimmee Prairie has continued to maintain its rural

character despite the tremendous growth in the northern portions of

Osceola County associated with Walt Disney World/Epcot Center (Table

2-1). Aside from development associated with the small towns of Yeehaw

Junction, Kenansville, and Fort Drum, there are limited developed

areas between Lake Kissimmee, the Kissimmee River and the St. Johns

River, and south to Fort Drum. On the north side of the study area,

there are small housing tracts on and near the northeast side of Lake

Marian. On the southeast side of the study area near Fort Drum, there

are 3 ranchette developments, including a large, relatively unpopulated

development approximately 3 km south of the NAS Kissimmee Prairie

Sanctuary.

A long-term potential threat to the Kissimmee Prairie is the

possible construction of a high-speed rail transportation system

linking Orlando to Miami. While a decision on the system will not be

made by the State of Florida until 1991, the current proposal includes

a rail system that would pass through the eastern portions of the study

area (High Speed Rail Transportation 1987). If any rail stops were to

be approved in towns like Yeehaw Junction, development would probably

occur in the area.

Given the recreational possibilities associated with both Lakes

Kissimmee and Marian, development pressures are likely to surface in

this area. A few years ago, Osceola County approved a proposal to build

an RV park on a site immediately north of Lake Marian. Although the








plans were dropped due to financial problems of the developer, the land

is still zoned for recreational development. West of the Kissimmee

River, and south of SR 60, are a number of retirement villages. Some

of the large private landholdings might eventually be sold for similar

developments.

Aerial hazards on the Kissimmee Prairie include powerlines and

radio towers. There are 2 adjacent north-south 500 kV transmission

lines on the far east side of the study area and a 230 kV transmission

line that crosses CR 523 approximately 40 km northwest of Kenansville

(Fig. 2-4). No transmission lines cross any of the proposed

reintroduction sites. There are several radio towers in the area,

although most are north of Lake Marian, or along the Kissimmee River

(Appendix B).



Discussion



Given the current land use situation, all 3 study areas could

support the reintroduction of whooping cranes. The proposed sites are

all large public landholdings with contiguous private, open lands.

Suitable crane habitat in the form of dry and wet prairie, improved

pasture, and in particular, wetlands, are available in sufficient

quantities.

Although Florida has lost large amounts of wetlands to drainage in

the past, current regulations are aimed at protecting wetlands on

private and public lands. Wetlands falling under the jurisdiction of

the state's regional water management districts, including "waters in

the state", and agricultural and silvicultural water management








systems, are protected primarily through the permitting program for

construction and operation of surface water management systems.

Under the water management districts' jurisdiction, preservation

of existing wetlands is considered the preferred alternative to any

mitigation, destruction, or compensation. Depending on the particular

water management district, regulations adopted in 1987 protect isolated

wetlands >0 or >0.4 ha from destruction or alteration without

appropriate mitigation. Other regulations prohibit ditching, draining,

or any other activities that divert surface flow from agricultural

lands, unless a permit is obtained (Florida Statute 403.927). Wetlands

falling under the jurisdiction of Florida Department of Environmental

Regulation (FDER), "waters of the state" are protected in similar ways

under the Henderson Wetlands Protection Act of 1984 (Florida Statute

403.927) through permitting programs.

Although wetlands habitats are now protected throughout Florida,

the losses of the adjoining upland areas to development decrease the

amount of suitable habitat available to cranes. Of the 3 proposed

reintroduction sites, the 2 sites in Southwest Florida (Myakka River SP

and Webb WMA) face increasing development pressures in and around their

boundaries. Housing developments occur along portions of the western

and northern boundaries of Myakka River SP. All but the eastern

boundary of the Webb WMA has some development.

The high population growth in coastal areas and the completion of

1-75 are the 2 major forces shaping these development pressures.

Forecasts for the future indicate that the human population will

continue to grow in both of these areas (Table 2-1).








While rural zoning ordinances often prohibit development of high

density housing, the result is an undesirable rural sprawl created by

the proliferation of >2-ha ranchettes. Development also potentially

causes disturbance to cranes and other wildlife, due to the activities

of both humans and domestic animals. While cranes will tolerate some

human activity, and in rare instances become relatively tame, for the

most part they prefer large open spaces with minimum disturbance (See

Chapter III). Studies of Florida sandhill cranes on the Kissimmee

Prairie (see Chapter IV) have determined that cranes maintain year-

round home ranges of 1.83 + 1.03 km2 (SD). They prefer herbaceous

wetlands, and open upland areas.

The habitat fragmentation caused by development forces cranes to

either travel longer distances to foraging and roosting sites, or to

temporarily or permanently abandon areas. In particular, habitat

conditions in and around nest wetlands are crucial because breeding

pairs usually stay in the vicinity of the nest pond during both the

nesting and prefledging period.

Activities and land uses outside the boundaries of managed areas

have many undesirable affects on species and ecological processes

within those areas (Schonewald-Cox and Bayless 1986, Noss 1987). While

the Webb WMA and Myakka River SP preserve large tracts of suitable

crane habitat, human populations continue to surround the boundaries

which often impose undesirable restrictions on habitat management and,

in particular, on prescribed burning practices. Smoke from prescribed

burns frequently is objectionable to the public. And at the same time,

the proximity of houses to public land boundaries forces site managers

to be very cautious to prevent fires from spreading across boundaries.








Population growth in the Webb WMA and Myakka River SP areas also

has increased the demand for potable water. Because desalinization is

still an expensive method to treat water, there is an increasing demand

for fresh water sources. Recent approval to install 5 shallow wells on

the Webb WMA for the future county jail is an example of this trend.

In all 3 areas, steps should be taken to assure that no habitat

degradation or undesirable decrease in the hydroperiod occurs as a

result of pumping on or nearby the proposed reintroduction sites.

Given the future prospects for continued development around the

Webb WMA and Myakka River SP, the Kissimmee Prairie should be ranked as

the first priority site for the potential reintroduction of whooping

cranes in Florida. In addition to the proposed reintroduction sites on

the Kissinmee Prairie (Three Lakes WMA and Kissimmee Prairie

Sanctuary), there are large public landholdings in the immediate area.

These public lands and the surrounding large, private landholdings

provide optimum conditions.for the expansion of both the Florida

sandhill and whooping crane populations.

At this point in time, the Webb WMA should be ranked as the second

priority site for the reintroduction of whooping cranes. The Webb WMA

represents the largest public-owned area of the 3 sites considered

(26,454 ha), and is managed by only one state agency, the FGFWFC. It

supports a large population of resident Florida sandhill cranes (see

Chapter III), and manages for crane habitat with its active controlled

spring burn program.

Myakka River SP should be ranked as the third priority site. When

combined with the Sarasota County Ringling-MacArthur Reserve these 2

properties include 21,500 ha of public lands. Until the remaining








3,240-ha inholding on the Ringling-MacArthur Reserve is purchased,

however, there is still the possibility of future development. While

habitat conditions on Myakka River SP have improved with the controlled

burn program, in some parts saw-palmetto is still rank.

Important to the future of any reintroduction scheme is the

continued existence of large tracts of undeveloped private lands. My

breeding surveys and home range studies on the Kissimmee Prairie have

indicated a strong preference by cranes for herbaceous emergent

wetlands and improved pasture (see Chapters III and IV). While most of

the private landowners on all 3 areas have a strong appreciation for

wildlife, economic constraints may, in time, force them to maximize

their financial gain from their lands in order to pay taxes and to

profit during periods of declining beef prices. Insufficient funds are

available to purchase open lands; therefore, some alternative

strategies should be examined to encourage the continued existence of

these large undeveloped lands.















CHAPTER III
PRODUCTIVITY OF FLORIDA SANDHILL CRANES
ON THREE SITES IN CENTRAL FLORIDA



Introduction



Aerial surveys using either photography or trained observers can

be an effective method of censusing crane populations. When a species

or its nest is large or conspicuous, and the census area is large and

not readily accessible by ground, aerial surveys may be the only

practical means to obtain the necessary information. Choice of the

aerial censusing technique to be used, visual-count or aerial

photography, will depend on the spatial distribution of the crane

population being studied. When cranes are concentrated in large flocks

such as migratory staging areas and wintering grounds, visual counts by

observers may be impractical. Blackman (1979) estimated Brolga crane

(Grus rubicundus) populations in Australia by photographing

concentrated and dispersed flocks during the non-breeding season.

Techniques combining aerial photography and visual counts have been

used successfully to estimate numbers of sandhill cranes staging in the

central Platte River Valley in Nebraska (Ferguson et al. 1979, Benning

and Johnson 1987), and for wattled cranes (Grus carunculatus) in Zambia

(Douthwaite 1974).

Population estimates of breeding cranes from aerial surveys

traditionally have relied on visual counts. Seasonal breeding pair
43








estimates usually are determined from total coverage of an areas) over

a 2-3 day period each year. Examples were the simultaneous aerial

surveys for breeding red-crowned cranes (Grus japonensis) conducted in

Japan (Masatomi et al. 1985), the People's Republic of China (Ma and

Jin 1987, Feng and Li in press), and the Soviet Union (Shibaev 1985,

Smirensky et al. 1985).

While a total count of a crane population using aerial techniques

may be a desired objective, it can be difficult and expensive to

achieve because total counts require good maps, complete coverage of

the census area, and an assurance that all animals are counted (Norton-

Griffiths 1975). A preferred and less expensive alternative to a total

population count is aerial sampling. There are 3 basic aerial sampling

methods: quadrat, block and transect. In quadrat sampling, a census

zone is divided into quadrats that usually are square shaped. During

the census, the entire sampled quadrat is intensively searched and all

animals within the quadrat are counted. Block sampling is similar to

quadrats; however, the boundaries are physical features identifiable on

the ground. As in quadrat sampling, each sampled unit is entirely

searched, and all animals counted (Norton-Griffiths 1975).

Transect sampling, counting animals while flying in a straight

line from 1 side of the sampling unit to the other, is the most popular

method and offers several advantages. It is cost effective, physically

comfortable for the observer, and easy to navigate and orient. With

respect to statistical analyses, transects produce a lower variance and

sampling error than blocks or quadrats. This is because transects tend

to reduce the effect on sample error caused by animals clumping

together (Norton-Griffiths 1975).








From 1984 to 1986, I conducted aerial transect surveys for nesting

Florida sandhill cranes in central Florida. The Florida sandhill crane

is a nonmigratory subspecies in the United States that occurs from

Okefenokee Swamp in southeast Georgia south to the Florida Everglades.

In central Florida, this subspecies has a long nesting season,

extending from January through the end of May.

Previous to this study, most of the available information on

productivity of sandhill cranes in central Florida was derived from 2

studies. Walkinshaw (1976, 1982, 1987) reported productivity data from

over 150 Florida sandhill crane nests on the Kissimmee Prairie during

1967-87. Layne (1983) monitored Florida sandhill crane pairs with

young during 1973-79 summer and fall road surveys in south-central

Florida.

Nest surveys coupled with fall roadside juvenile recruitment

surveys were part of a larger study designed to evaluate 3 Florida

sites proposed for whooping crane reintroduction. The revised edition

of the Whooping Crane Recovery Plan (U.S. Dept. Interior 1986) has

identified several biological criteria that all third whooping crane

population studies need to address. One of these criteria includes

determining which aspects of the biology of the resident sandhill crane

populations would be affected by reintroduction of whooping cranes.

The objectives of the nest surveys were to (1) map the seasonal

distribution of nesting Florida sandhill crane pairs on the 3 sites and

their surrounding areas, (2) estimate the density of the Florida

sandhill crane breeding population on the 3 sites and their surrounding

areas, (3) determine what factors are influencing breeding, and








(4) characterize the nest sites selected, and (5) subsequently

determine annual recruitment of fledged juveniles and brood size.



Methods



From 1984 to 1986, field studies were conducted on 3 sites in

central Florida. These included the Kissimmee Prairie in Osceola and

Okeechobee counties (including Three Lakes Wildlife Management Area and

the National Audubon Society Ordway-Whittell Kissimmee Prairie

Sanctuary), Myakka River State Park (SP) in Sarasota and Manatee

counties, and the C.M. Webb Wildlife Management Area (WMA) in Charlotte

County (see Fig. 1-1). Study areas included not only the potential

whooping crane reintroduction sites but also the surrounding areas.

See Chapter II for descriptions of locations and habitats.

Rainfall occurs unevenly throughout the year on all 3 areas.

Florida sandhill crane nesting occurs during the dry season, November

through April. During the wet season, from May to October, 70-80% of

the rainfall occurs (Fig. 3-1).



Aerial Surveys of Nests

Aerial sampling for Florida sandhill crane nests was considered

the most accurate and efficient means of estimating the size of the

local breeding populations due to the long breeding season, the large

size of the proposed release sites, the great distances between sites,

and the heterogeneous terrain.

Sampling regime. Aerial surveys were conducted in all study areas

approximately once every 2-3 weeks (range 8-34 days). Surveys began in


















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mid-January and were completed by mid-May, except in 1984 when surveys

began on 1 March. All regular surveys were conducted from a Cessna 172

Skyhawk flying at a speed of 145 km/h.

For the 1984 season, parallel east-west transects, approximately

1.6 km apart, were flown at a height of 75 m across each study area. A

strip width was not defined for each transect; however, most

observations occurred within 0.2 km on each side of the plane. The

pilot looked for nesting cranes out the port side of the plane while I

observed out the starboard side.

For the 1985 and 1986 aerial surveys, systematic aerial fixed-

strip transects were developed. Compared to random sampling,

systematic sampling is the more efficient means of mapping the

distribution of animals and making comparisons of the numbers observed

on a specific site over time. Systematic sampling also avoids the

navigational problems associated with random transect sampling

(Caughley 1977). When this study began, systematic aerial fixed-strip

transect sampling already was being used successfully in the Everglades

National Park (South Florida Research Center 1985) to estimate the

population size and distribution of wading birds.

With systematic aerial transect sampling, predetermined and

consistently-spaced parallel transects are flown across the study area.

Initially, a grid system is established, then east-west flight lines

are spaced to bisect each row of grid squares. For this study, a 3 km

x 3 km grid system was established for each study area (Fig. 3-2).

Transect flights were accurately repeated using a Loran-C navigation

receiver that had been previously programmed with each transect's

starting and ending points, and calibrated at the beginning of each









49









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flight at a predetermined location. Transect lengths varied within and

between each study area as most latitudinal starting and ending points

were landmarks such as powerlines, roads, or lakes.

For 1985 and 1986 aerial surveys, a field assistant replaced the

pilot as the second observer. Each of the 2 observers, 1 in the front

with the pilot and the other in the back seat directly behind the

pilot, recorded all active nests detected within a 160 or 200 m

interval. Thus, 12-13% of each study area was sampled during each

survey. The fixed-strip width for each observer was established by

maintaining a constant plane height of 91 m and defining each

observer's visual boundaries (Fig. 3-3). Each observer's strip width

was defined by that area viewed between 2 streamers attached to the

wing struts and marks on the windows. The exact position of the

streamers and window marks were calculated using a method outlined by

Pennycuick and Western (1972).

Florida sandhill cranes in central Florida generally build their

nests with emergent vegetation in relatively shallow wetlands <1 m deep

(Walkinshaw 1981, this study). Nests in upland habitats are rare and

have been reported on only a few occasions during this century.

Although sandhill cranes are difficult to observe from fixed-wing

aircraft because of their cryptic coloration, their nests usually are

large and conspicuous. Because the cranes often construct more than 1

nest platform, I recorded observations as a nest only if (1) a crane

was present, (2) an egg was visible, but no crane was present, or (3)

adult cranes and chicks were on the nest.

During the 1985 and 1986 flights I was able to identify individual

nests by recording Loran-C locations and making diagrams of the













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wetland's shape and the nest's position in it. In this study, I found

that nautical distance to the end of the transect was faster and less

confusing to determine and record than the longitude. After each

flight I pinpointed the nest using a combination of 1:24,000 Mark Hurd

aerial photograph maps and U.S. Geological Survey (USGS) topographic

maps.

Areas surveyed. The Webb WMA survey area included approximately

405 km2. Flight transects began at the northwest corner of the Webb

and ended 3 km south of the Webb (see Fig. 2-1). During 1984, between

9 and 12 transects were flown per flight for a total of 204-240 km.

For 1985 and 1986, 6 transects were flown per flight for 135 km.

Transects were 20-25.8 km long, and traversed the entire width of the

Webb from 1-75 to SR 31 during 1984, and from US 41 to SR 31 during

1985 and 1986. Three transects extended approximately 4 km east into

Babcock Ranch during 1985 and 1986.

The Myakka River SP survey area included approximately 597 km2 in

1984 and 1985, and 694 km2 in 1986. Areas surveyed included Myakka

River SP, Sarasota County Ringling-MacArthur Reserve, and surrounding

private ranches. For 1984 and 1985, flight transects began at Sugar

Bowl Road, approximately 11.3 km north of SR 72, and ended

approximately 2.5 km north of 1-75 (see Fig. 2-3). For 1986, 2

transects were added at the north end of the study area, accounting for

approximately 35 km. Transects oriented east-west extended

approximately 24.5 km from Sugar Bowl Road to a major north-south

powerline. South of SR 72, transects were extended on the east side

approximately 6 km. For 1984, between 7 and 12 transects per flight

covered 172-295 km, respectively. During 1985, 7 transects usually








were flown, totalling 188 km. With the exception of 1 helicopter

flight, for 1986 surveys, 8 or 9 transects were flown for a total of

219-229 km.

The Kissimmee Prairie survey area included 1058 km2 in 1984 and

1985, and 1,182 km2 in 1986. Areas surveyed included the portions of

Three Lakes WHA south of the Florida Turnpike, Prairie-Lakes State

Preserve, and NAS Kissimmee Prairie Sanctuary, as well as surrounding

private ranches. Transects began at the intersection of CR 523 and

Overstreet Road, approximately 1.5 km southeast of the northwest

boundary of Three Lakes WMA (see Fig. 2-4). Transects ended

approximately 3 km south of the Kissimmee Prairie Sanctuary in

Okeechobee County. Because of the configuration of the region

surveyed, transect length varied from 4.8-28.7 km long during 1984, and

9.3-31.3 km during 1985 and 1986. Transects, oriented east-west,

usually were traversed from the Florida Turnpike to Lake Kissimmee

south to Kenansville. Transects south of Kenansville extended from

US 441 to Lake Kissimmee or else to within 1.7 to 12 km of the

Kissimmee River.

For the 1986 surveys, 7 transects (Nos. 5-11) were extended past

US 441 to a major north-south powerline. In all, between 16 and 26

transects were flown per survey for 293-488 km during 1984. During

1985 and 1986, either 17 or 18 transects were flown per survey for

330-405 km. On 2 occasions, 24 March and 1 April 1986, 5 and 6 extra

transects were flown over Three Lakes WMA for an additional 36.6 and

43.6 km, respectively. These transects were parallel to the regular

transects and at approximately 1.5-km intervals from the usual

transects; the length of these transects varied from 4.8 to 8.2 km.








Detectability. In 1985 and 1986, I conducted a series of 3

experiments to determine how aerial censusing methods and flight speed

affected nest detectability. In 1985, I censused study areas using

both the fixed-strip transect and the quadrat sampling methods.

Immediately following completion of a transect survey, 3 to 6, pre-

selected 3 km x 3 km grid cells (quadrats) were searched for nests.

Helicopters were used to test how flight speed effects

detectability. In 1985 and 1986, each area was surveyed by helicopter

once each season. In 1985, the 6 pre-selected quadrats on each study

area were searched for nests by fixed-wing aircraft, and then by

helicopter within 3 days. In 1986, fixed-strip aerial transect surveys

were flown by helicopter in a subset of the previously surveyed

transects. These flights were conducted once in Webb WMA and Myakka

River SP and on 2 occasions in the Kissimmee Prairie.

Breeding pair population estimates. In order to estimate the

breeding population from the fixed-strip transect surveys, I used a

ratio-estimation method for unequal length transects. This method was

popularized by Jolly (1969a) and is referred to as the Jolly II method.

The crude density of breeding pairs/km2, R, for each survey was

estimated using the following formula:

R = Zy/Zz

where y is the number of nests counted in the transect and z is the

area transectt length multiplied by total strip width) of a sample

transect.

The estimated population size for each survey is:

Y = R Z








where Y is the estimated breeding population, Z is the total area of

the census zone, and R is the estimated density.

The sample error of Y, SE(Y), is estimated as Js2 (Y) where

s2Y) = (N(N-n)/n) (Sy2 (2 R Szy)+ (R2 S2)

In this formula, s2(Y) is the sample variance of Y, N is the number of

possible transects in the population, n is the number of transects in

the sample, Sy2 is the variance in number of nests counted in the

transects, Szy is the covariance between the nests counted and the area

per transect, and Sz2 is the variance between the areas of all the

sample transects.

The 95% confidence interval (CI) of Y is:

CI = +t SE(Y)

where t is for n-1 degrees of freedom, and n is the number of

transects.

For 1985 and 1986 data, I estimated a breeding population for the

entire season, by totaling only initial nest sightings (no repeat

sightings) for each transect for all flights combined. Crude density,

total breeding pairs, and sample error were calculated using the above

formulae. Final estimations were then adjusted downward to account for

renesting. I used a 35% adjustment figure based on a recent study of

the incidence of renesting in Florida sandhill cranes (S. Nesbitt,

FGFWFC, pers. commun., 1987).

For quadrat sampling, I used the Jolly I method (Jolly 1969a) for

equal-sized sampling units to estimate the breeding pair population and

95% confidence limits. With this method, the population estimate is

calculated from the average number of nests counted in each quadrat and

the population variance is calculated from counts among quadrats.








Environmental Correlates of Nesting Densities

I analyzed breeding pair densities for all fixed-wing flights with

respect to several environmental variables. These included

photoperiod, water levels, drying and rising rate, rainfall, and

temperature.

Water levels from shallow (<11 m) groundwater wells monitored by

the USGS were used as an index of surface conditions. On the Myakka

River SP and Kissimmee Prairie study areas, maximum daily water levels

were available. On the Webb study area, daily water levels were

interpolated from monthly groundwater well readings (USGS files),

assuming uniform changes between sampling dates. A daily drying or

rising rate was calculated as the difference from the previous day's

water level. Daily rainfall and maximum and minimum temperature data

were obtained from weather stations of the National Oceanic and

Atmospheric Administration and the South Florida Water Management

District. All weather and groundwater well data were collected either

on the study area or within 4.5 km of a study area boundary.

I used the Statistical Analysis System (SAS) (SAS Inst. 1985a) to

perform statistical summaries and analyses. Spearman rank correlations

were used to investigate the associations between breeding pair

densities by flight and environmental variables. I then used stepwise

regression to determine which variables were the best predictors of

breeding pair densities. The dependent variable, breeding pair

density, was weighted by the standard error. Only crude densities

determined from fixed-wing transect surveys were used in these

analyses. The critical level for rejecting a null hypothesis was P <

0.05.








Nest Site Characteristics

Nests identified during aerial surveys during the 1985 and 1986

seasons were plotted on aerial photographs. Land ownership was

determined from courthouse records for nests in Okeechobee County, and

the published plat books for nests in Osceola, Sarasota, Manatee, and

Charlotte counties (Rockford Map Publishers 1982a,b; Florida Plats

1984, 1985).

For Myakka River SP and the Webb WMA, each nest was assigned a

wetland code based on the National Wetlands Inventory 1:24,000 scale

map of the region (Cowardin et al. 1979). For the Kissimmee Prairie,

wetland codes were determined from ground truthing and aerial

photographs. Aerial photographs of 1:4,800 scale were used to

determine the size of the wetland and the surrounding land use. On the

Webb WMA, FDOT vegetation maps (FDOT 1978) were used as supplemental

information.

On the Kissimmee Prairie, nests previously located from aerial

transects and from ground searches of selected areas were visited

following hatching. Nest site characteristics (size, composition of

nest, height and type of surrounding dominant vegetation, shoreline)

and evidence of hatching success were recorded for 74 nests.



Fall Juvenile Recruitment Surveys

In order to obtain an estimate of the average brood size and

annual juvenile recruitment for the 3 areas, surveys for juvenile-

plumaged cranes were conducted between August and October, before the

arrival of migratory greater sandhill cranes. Juvenile recruitment

surveys consisted of counting all cranes observed over a 2-3 day period








while driving public and private roads, and observing known off-road

traditional use areas and roost sites on and around the study area.

Feeding and roosting concentrations located as far as 18 km from the

study areas' boundaries were included in the overall counts. With the

exception of 1984 when only 1 survey was made at Myakka River SP area,

2 surveys were conducted on each study area per year.



Results



Nesting Chronology and Density

1984 Breeding season. Eleven flight days during Spring 1984

resulted in 5 surveys of Webb WMA, 4 surveys of Myakka River SP, and 5

surveys of the Kissimmee Prairie study areas. A flight on 29 February

over the Webb WMA study area served principally to refine census

techniques. The last survey was completed on 14 May 1984.

Water levels in shallow groundwater wells throughout the 1984

breeding season were higher than either 1985 or 1986. These higher

levels initially were the result of above normal precipitation on the 3

areas during November and December (Table 3-1). Both the Kissimmee

Prairie and Webb WMA study areas both had precipitation slightly above

normal for November and December (15.3 cm and 14.9 cm, respectively),

and close to average rainfall during January (2.0 cm and 1.5 cm,

respectively). Myakka River SP, however, had unusually wet conditions

due to heavy rainfall during November and December. A total of 32 cm

of precipitation fell during this period, approximately 21 cm above the

normal rainfall for these months. While water levels began to fall

throughout January and February, precipitation in late February and









Table 3-1. Total precipitation and departure from normal (cm) on
3 study areas in central Florida for 1 May 1983 30 April 1984.


Kissimmee Prairiea Myakka River SPb Webb WMAb

Month/yr Precip Depart Precip Depart Precip Depart


May 1983 5.0 -8.4 5.1 -4.7 2.2 -8.0

Jun 1983 24.2 3.8 23.7 2.5 17.9 -1.9

Jul 1983 9.5 -10.5 30.2 8.8 15.7 -2.0

Aug 1983 9.5 -7.2 18.8 -4.9 17.1 -2.0

Sep 1983 12.2 -4.2 29.6 7.8 24.6 5.5

Oct 1983 11.5 2.6 6.8 -1.8 10.5 1.0

Nov 1983 4.8 0.0 11.2 5.8 8.3 4.3

Dec 1983 10.5 5.3 20.8 15.3 6.6 2.1

Jan 1984 2.0 -3.6 2.5 -3.9 1.5 -3.9

Feb 1984 6.4 -1.1 6.2 -1.6 8.4 2.5

Mar 1984 5.5 -0.9 13.7 6.6 13.6 7.5

Apr 1984 6.0 0.3 8.4 2.9 8.2 3.7


Total 107.1 -23.9 177.0 32.8 134.6 8.8


a Calculated from S-65 dock at south end of Lake Kissinmmee, South
Florida Water Manage. District, unpubl. data 1985.
b U.S. Dep. Comm. 1983, 1984.








March caused a series of rising water levels that were sustained until

mid-April (Figs. 3-4, 3-5, 3-6).

Peak nesting for 1984 was observed on all 3 areas during the 9-10

March aerial surveys (Table 3-2, Figs. 3-4, 3-5, 3-6). On subsequent

surveys, nest counts dropped by 40 to 60%. The number of nests sighted

continued to decline throughout the remaining surveys on the Myakka

River SP and Kissimmee Prairie areas. Nest counts on the Webb WMA

study site, however, did not drop sharply until the final mid-May

flight.

Because nesting surveys were not conducted during January and

February 1984, it was not possible to document the beginning of the

breeding season in that year or to compare the nesting chronology with

previously compiled Florida nesting records. The peak counts from the

9-10 March flights on the 3 areas, however, are 2 weeks later than

Walkinshaw's (1987) estimated 19-21 February mean (N 14) for nest

initiation on the Kissimmee Prairie.

On the Kissimmee Prairie, 58 nests were located along the

transects during 5 aerial surveys. The highest crude nesting density

for all 3 study areas in 1984, 0.17 breeding pairs/km2 (31 nests) were

recorded on this study area during the 10 March aerial survey (Fig.

3-4). On Webb WMA study area, 35 nests were located on transects, and

peak nesting occurred on 9 March (Fig. 3-6). Compared to the other 2

areas, however, Webb WMA maintained a relatively high density of active

nests until the end of April. It is quite likely that the 13 cm

rainfall event on 13 March may have flooded nests and stimulated

renesting. This speculation is supported by Walkinshaw's (1976)










0.2

0.175

0.15

0.125
CM
E 0.1

S0.075

0.05

0.025

0





19

18.85

18.7

18.55

18.4

18.25

S18.1
2-'


S17.8

17.85
17.65

17.5


~plr%~ s


1 15 1 15 1 15 1 15 1 15


Feb


Mar


May


MONTH
Figure 3-4. Comparison of nesting densities and groundwater-
well water levels at Kissimmee Prairie survey area, 1984-1986
breeding seasons. (a) Breeding pair densities as determined
from aerial fixed-strip width transect surveys. (b) Daily
maximum water levels from shallow well OS182 on Kissimmee Prairie.


1 15 1 15 1 15 1 15 1 15
Jan Feb Mar Apr May


--1984 -1985 -u- 186
land surface


-

s e s s n e s i s


-


*
4



















0.1

S0.075

0.05-

0.025--


1 15 1 15 1 15 1 15 1 15

Jan Feb Mar Apr May


9.7'
-9.7 1084 -B- 1985 -0-1988
9.55

9.25
8.1-
S. 895 -
mE.





8.05
1 8.65




7.9


7 .6 -,-,
1 15 1 15 1 15 1 15 1 15

Jan Feb Mar Apr May
MONTH
Figure 3-5. Comparison of nesting densities and groundwater-
well water levels at Myakka River State Park survey area,
1984-1986 breeding seasons; (a) Breeding pair densities as
determined from aerial fixed-strip transect surveys. (b) Daily
maximum water levels from shallow well 19E on Sarasota County
Ringling-MacArthur Reserve.










0.2

0.175

0.15

ct 0.125
E
0.1

-. 0.075

0.05

0.025

0


6.7


3- "'" "-%%%%-

1



7
_-f


*** 1984 -B-- 1985 1986o

















1 15 1 15 1 15 1 15 1 15

Jan Feb Mar Apr May




S*1984 -- 1985 -0 1988
land surface


1 15 1 15 1 15 1 15


Feb


Apr


1 15

May


MONTH
Figure 3-6. Comparison of nesting densities and groundwater-well
water levels at Webb WMA survey area, 1984-1986 breeding seasons.
(a) Breeding pair densities as determined from aerial fixed-strip
transect surveys. (b) Monthly water levels from shallow well
L-3209 near Webb WMA.


1I


1


*-.s
S6.
01
3s6,
La-
3 5.


i


S;









Table 3-2. Peak nesting date by year as determined from aerial
surveys.


1984a 1985 1986

Webb WMA 9 March 19 March 12 March
5 April

Myakka River SP 9 March 29 April 12 April

Kissimmee Prairie 10 March 14 March 17 February


a Surveys did not begin until 1 March.








findings that for 75 Florida sandhill crane nests, the average height

of a nest above the water was 10.9 cm.

Peak nesting densities occurred at the Myakka River SP study area

on 9 March when 11 nests were counted for an estimated 0.11 breeding

pairs/km2 (Fig. 3-5). Despite 8 cm of rain on 13 March, and relatively

high water levels through mid-April, Myakka River SP study site did not

maintain high nesting densities throughout April. In all, 24 nests

were located during 4 surveys on the study area.

1985 Breeding season. In 1985, a severe drought on all 3 study

areas caused the majority of wetlands to dry up by early April. From

May 1984 to April 1985, all 3 areas recorded below average monthly

rainfall in at least 9 of the 12 months (Table 3-3). Similarly, water

levels in shallow groundwater wells were substantially lower than 1984.

On Myakka River SP, January through April monthly maximum water levels

ranged from 76 cm (April) to 112 cm (February and March) lower than the

previous season. On the Kissimmee Prairie, monthly maximum water

levels ranged from 13 cm (April) to 53 cm (February) lower. On the

Webb WMA study area, water levels receded steadily as the season

progressed. Rainfall on the Kissimmee Prairie and Myakka River SP

study areas caused water levels to rise slightly during March and April

(Figs. 3-4, 3-5).

As a consequence of the drought, there were few nesting attempts

recorded during the 1985 breeding season (Figs. 3-4, 3-5, 3-6).

Estimated crude densities for the breeding season were very low on all

3 study areas and ranged from 0.03 to 0.05 breeding pairs/km2

(Table 3-4).









Table 3-3. Total precipitation and departure from
3 study areas in central Florida for 1 May 1984 -


normal (cm) on
30 April 1985.


Kissimmee Prairiea Myakka River SPb Webb WMAC

Month/yr Precip Depart Precip Depart Precip Depart


May 1984 16.2 2.8 10.9 1.1 10.9 0.7

Jun 1984 11.5 -8.9 7.3 -13.9 17.6 -2.1

Jul 1984 22.6 2.6 39.3 17.9 25.7 8.0

Aug 1984 14.3 -2.4 18.5 -5.2 13.2 -5.9

Sep 1984 7.4 -9.0 10.6 -11.2 10.2 -8.9

Oct 1984 2.8 -6.1 7.0 -1.5 4.3 -5.2

Nov 1984 10.1 5.3 6.0 0.6 5.3 1.3

Dec 1984 1.4 -3.8 0.9 -4.6 1.7 -2.8

Jan 1985 1.8 -3.8 2.1 -4.4 0.7 -4.7

Feb 1985 1.8 -5.7 2.5 -5.4 2.4 -3.5

Mar 1985 3.7 -2.7 7.1 -0.1 0.6 -5.5

Apr 1985 4.9 -0.8 5.3 -0.2 3.6 -0.8


Total 98.5 -32.5 117.5 -26.9 96.2 -29.4


a Calculated from S-65 dock at south end of Lake Kissimmee, South
Florida Water Manage. District, unpubl. data 1985.
b U.S. Dep. Comm. 1984, 1985.
c U.S. Dep. Comm. 1985 and Webb WMA files.






67










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On the Webb WMA study area, observations during the 8 fixed-wing

transect surveys, and 1 helicopter quadrat survey included 2 nests on

transects (Fig. 3-7), no nests in quadrats, and 3 nests sighted

incidentally. Of the 5 nests located, 60% (3) were within the Webb WMA

boundaries (Appendix C).

At Myakka River SP study area, the first nest of the 1985 season

was observed on 11 March during an aerial search of a quadrat. No

nests were counted on the transects until over 1 month later (Fig.

3-5). Peak nesting occurred on 29 April when 4 nests were observed on

transects.

During 1985 on Myakka River SP study area, there were 8 fixed-wing

transect surveys and 1 helicopter quadrat survey. In all, 12 nests

observed from the air on the Myakka River SP study area included 5

transect nests (Fig. 3-8), 3 quadrat nests (Fig. 3-9), and 4

incidentally observed nests. An additional 2 nests were located

through ground efforts (H. Jelks, Univ. Florida, pers. common., 1985).

Four nests (29%) were located within the Park, and 1 nest on the

Sarasota County Ringling-MacArthur Reserve (Appendix C).

During the 7 aerial nesting surveys on the Kissimmee Prairie in

1985, 8 nests were located on transects (Fig. 3-10) and 1 nest in a

quadrat (Fig. 3-11). Another 11 nests and 1 brood of flightless (<60-

70 days old) chicks (hereafter referred to as prefledged) were located

incidentally from both fixed-wing aircraft and helicopter for a total

of 20 nests from the air. When transect nests alone are considered,

the estimated 1985 peak nesting period was 14 March (Table 3-2, Fig. 3-

4), very close to the 1984 peak on 10 March.























































LI


In


C


w

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r1





44 4

A.



M


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0



0 4r4
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d0 *




a



41 Ce
41
0 Cd C






10
M r- 1









a n










W0 0
l- m
rh *
Ijn)cf













































Figure 3-8. Spatial distribution of Florida sandhill crane nests
by 3 km x 3 km grid cells observed during 8 systematic aerial
transect surveys of Myakka River State Park and surrounding lands,
January-May 1985. No repeat sightings are included.




















rj ~ t __


0
ti ^ -^ -

--

^x---1


Figure 3-9. Preselected 3 km x 3 km quadrats surveyed for Florida
sandhill crane nests during 8 aerial surveys on Myakka River
State Park and surrounding lands, January-May 1985. Numbers
denote nests sighted.


1c arKX
alt


.. .-


ekke











































O77 1


neLss nest nests _

Figure 3-10. Spatial distribution of Florida sandhill crane
nests by 3 km x 3 km grid cells observed during 7 systematic
aerial transect surveys on the Kissimmee Prairie, Florida,
January-May 1985. No repeat sightings are included.


2

























































Figure 3-11. Preselected 3 km x 3 km quadrats surveyed for Florida
sandhill crane nests during 8 aerial surveys on Kissimmee Prairie,
January-May 1985. Numbers denote nests sighted.








In addition to the aerial surveys on the Kissimmee Prairie, ground

efforts detected an additional 9 nests, and 9 pairs with prefledged

chicks (Appendix C). In all, only 1 nest was located on public lands

during this breeding season.

1986 Breeding season. Compared with the 1985 breeding season,

nesting attempts in 1986 were substantially more numerous on the

transects: nests increased on the Myakka River SP study area from 5 to

27 (Fig. 3-12), on the Webb WMA study area nesting efforts increased

from 2 to 38 (Fig. 3-13), and on the Kissinmmee Prairie study area from

8 to 54 (Fig. 3-14). Estimated crude densities for the 1986 breeding

season ranged from a high of 0.52 breeding pairs/km2 on the Webb WMA

study area to 0.22 breeding pairs/km2 on Myakka River SP study area

(Table 3-4). This increase in nesting attempts is most likely due to

better water conditions on all 3 areas throughout the breeding season.

Rainfall for May 1985 through April 1986 continued to be below

average on all but the Webb WMA study area (Table 3-5); however,

rainfall deficits were not as extreme as during the previous 12 months.

For the 6 month dry season, November 1985 through April 1986, both the

Kissimmee Prairie and the Webb WMA recorded above average rainfall,

+0.8 cm and +0.4 cm, respectively, while the Myakka River SP study area

recorded a -6.6 cm departure from normal.

Water levels in groundwater wells on all 3 areas were

characterized by weak, interrupted drying trends from January through

the end of March. From April through the end of the breeding season,

water levels continued to decline steadily on Myakka River SP and the

Webb WMA.













































Figure 3-12. Spatial distribution of Florida sandhill crane nests
by 3 km x 3 km grid cells observed during 10 systematic aerial
transect surveys of Myakka River State Park and surrounding lands,
January-May 1986. No repeat sightings are included.























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Figure 3-14. Spatial distribution of Florida sandhill crane nests
by 3 km x 3 km grid cells observed during 11 systematic aerial
transect surveys on the Kissimmee Prairie, Florida, January-May
1986. No repeat sightings are included.









Table 3-5. Total precipitation and departure from
3 study areas in central Florida for 1 May 1985 -


normal (cm) on
30 April 1986.


Kissimmee Prairiea Myakka River SPb Webb WMAc

Month/yr Precip Depart Precip Depart Precip Depart


May 1985 8.8 -4.6 0.6 -9.2 9.5 -0.7

Jun 1985 18.3 -2.1 14.2 -7.0 29.9 10.1

Jul 1985 17.1 -2.7 19.0 -2.4 17.1 -0.6

Aug 1985 15.0 -1.6 23.1 -0.7 17.7 -1.4

Sep 1985 10.6 -5.5 24.4 2.6 13.9 -5.2

Oct 1985 3.2 -5.4 4.9 -3.7 7.1 -2.4

Nov 1985 7.6 2.6 7.8 2.4 9.4 5.4

Dec 1985 4.3 -0.9 1.0 -4.5 6.1 1.5

Jan 1986 6.3 0.7 4.6 -1.9 1.4 -4.0

Feb 1986 3.9 -3.4 4.2 -3.6 3.0 -2.9

Mar 1986 13.1 6.4 11.2 4.0 9.9 3.9

Apr 1986 0.8 -4.6 2.5 -3.0 1.0 -3.5


Total 109.0 -21.1 117.5 -27.0 126.0 0.2


a Calculated from S-65 dock at south end of Lake Kissimmee, South
Florida Water Manage. District, unpubl. data 1986.
b U.S. Dep. Comm. 1985, 1986.
c U.S. Dep. Comm. 1985, 1986 and Webb WMA files.








The earliest successful nesting attempt on the Webb WMA study site

was initiated in late December 1985 (H. Anderson, FGFWFC, pers.

common., 1986). The last nesting attempt was recorded on the 8 May

flight. For 1986, peak nesting occurred on 12 March, approximately the

same time as the 1984 nesting season (Table 3-2, Fig. 3-6). Of 47

nests located on the ground and from the air, 74% (35) were located

within the Webb WMA property boundaries, and 2% (1) on Charlotte County

Airport (Appendix C).

At Myakka River SP study area the 1986 peak nest density was

recorded on 12 April (Fig. 3-5). During 9 fixed-wing and 1 helicopter

survey, a total of 43 nests were observed. These included 27 transect

nests (Fig. 3-12) and 16 nests incidentally observed. An additional 3

families with prefledged chicks were located through ground efforts

(R. Dye, FDNR, pers. commun., 1986) (Appendix C). Fifteen percent of

the nests and family groups (7) were located on public lands, including

11% (5) within Myakka River SP.

During 1986 aerial nesting surveys on the Kissimmee Prairie, 59

nests initially were located on regular transects during 9 fixed-wing

surveys and 2 helicopter surveys. This total was reduced to 54

transect nests (Fig. 3-14), after ground-truthing failed to adequately

confirm 5 nests. Another 35 nests were located incidentally from the

air for a total of 89 nests. In addition to these 89 nests, 22 nests

and 26 pairs with prefledged chicks were located from ground efforts

for a total of 137 known nesting attempts. Of the 137 nests and/or

pairs with prefledged chicks, 8.2% (11) nests were on state lands,

1.5% (2) on the NAS Kissimmee Prairie Sanctuary, and the remainder on

private lands (Appendix C).








The earliest known successful nesting attempt was initiated the

first week of January in Osceola County, and the latest laying date

recorded was approximately 18 May in Osceola County. When only aerial

transect densities are considered, the estimated peak nesting density

was 17 February 1986 (Fig. 3-4). This date is approximately 1 month

earlier than the 1984 and 1985 nesting peaks for the area and is

earlier than both the Webb WMA and Myakka River SP study areas by 1 and

2 months, respectively (Table 3-2).



Population Estimates and Confidence Limits

When population estimates and 95% confidence limits were

determined for all 1984-1986 fixed-wing surveys, over one-half of the

lower confidence limits included zero or a negative number (Tables 3-6,

3-7, 3-8). The large variances in the population estimates for each

survey are a result of the small number of transects sampled relative

to the census areas, the low numbers of nests counted per flight, and

the variability in the distribution of nests within each study area.

Because exact locations of nests could not be determined for the

1984 surveys, an estimated total breeding pair population for that

season could not be determined. For the 1985 season, the estimated

breeding population based on the total number of unique nests counted

on all transect surveys was 12 + 19 pairs on the Webb WMA, 31 + 30

pairs on Myakka River SP, and 49 + 40 pairs on the Kissiamee Prairie.

In 1986, all 3 areas had much higher population estimates 211 + 62

pairs on the Webb, 150 + 60 pairs on Myakka River State Park, and 300 +

111 pairs on the Kissimmee Prairie (Table 3-4). When the confidence

limits are expressed as a percentage of the estimated breeding pair






81

Table 3-6. Estimated breeding pairs (Y) and 95% confidence intervals
(CI) determined from aerial fixed-strip transects surveys at 3 areas in
central Florida, Spring 1984.


Transects
Date surveyed Nests Y 95% CI


Webb WMA

9 Mar 10 14 60 + 32

26 Mar 12 6 23 + 22

17 Apr 10 7 32 + 31

30 Apr 10 6 29 + 20

14 May 10 2 9 + 12

Myakka River SP

9 Mar 10 11 61 + 35

26 Mar 12 8 37 + 20

17 Apr 11 3 15 15

14 May 7 2 15 + 21

Kissimmee Prairie

1 Mar 16 9 79 + 46

10 Mar 24 31 178 + 74

2 Apr 26 14 75 + 40

16 Apr 26 3 16 + 17

7 May 24 1 6 11






82

Table 3-7. Comparison of estimated breeding pairs (Y) and 95% confidence
intervals (CI) determined from aerial fixed-strip transects with estimates
from intensive aerial searches of 3 km x 3 km quadrats at 3 areas in
central Florida, Spring 1985.


Transects Quadrats

Date N Nests Y + 95% CI N Nests Y + 95% CI


Webb WMA

23 Jan 6 0 0 --

4 Feb 6 0 0 -

26 Feb 6 0 0 3 0 0

11 Mar 6 0 0 3 0 0

19 Mar 6 1 8 + 21 4 0 0

5 Apr 6 1 8 + 20 6 0 0

17 Apr 6 0 0 4 0 0

29 Apr 6 0 0 4 0 0

Myakka River SP

23 Jan 7 0 0 -

26 Feb 7 0 0 3 0 0

11 Mar 7 0 0 3 1 21 + 90

19 Mar 7 0 0 3 0 0

5 Apr 6 0 0 6 1 11 26

17 Apr 7 3 25 + 27 3 1 21 + 90

29 Apr 7 4 33 + 41 3 Oa 0

9 May 7 2 17 + 26 2 0 0

Kissimmee Prairie

29 Jan 18 1 8 + 17 -

18 Feb 18 2 17 + 33 3 0 0

4 Mar 18 2 17 + 33 3 0a 0








Table 3-7.---continued.


Transects Quadrats

Date N Nests Y + 95% CI N Nests Y + 95% CI


14 Mar 17 4 35 + 40 3 1 39 + 166

9 Apr 17 1 9 + 18 3 0 0

24 Apr 18 2 17 + 23 3 0 0

6 May 18 0 0 3 0 0


a Known nest was not detected.