Mitigation of fish and wildlife values in rock-mined areas of South Florida

Technical Report No. 6

Mitigation of Fish and Wildlife

Values in Rock-mined Areas of

South Florida, Part II: Wildlife

Robert W. Repenning

Cooperative Fish and Wildlife Research Unit

117 Newins-Ziegler Hall

School of Forest Resources and Conservation

Institute of Food and Agricultural Sciences

University of Florida, Gainesville, FL 32611

Submitted to:

Dr. Ronnie Haynes

Project officer

U.S. Fish and Wildlife Service,

Region 4

75 Spring St. S.W., Suite 1276

Atlanta, GA 30303

January 12, 1986

TABLE OF CONTENTS

Page
ACKNOWLEDGMENTS ii

INTRODUCTION 1

STUDY AREA DESCRIPTION 2

CLIMATE AND GEOGRAPHY OF DADE COUNTY 2

WILDLIFE HABITATS OF DADE COUNTY 4

WILDLIFE OF DADE COUNTY 7

STUDY SITE SELECTION 8

METHODS 23

VEGETATION SAMPLING 23

WILDLIFE SURVEY METHODS 23

RESULTS 25

VEGETATION 25

WINTER BIRD POPULATION STUDY 27

BREEDING BIRD POPULATION STUDY 33

USE OF STUDY SITES BY OTHER WILDLIFE 37

DISCUSSION 38

WILDLIFE USE OF THE NATURAL HABITATS 38

WILDLIFE USE OF ROCK MINES 48

CONCLUSIONS 51

GUIDELINES FOR ENHANCING WILDLIFE USE OF ROCK MINES 51

LITERATURE CITED 54

APPENDIX 59

ANNOTATED BIBLIOGRAPHY OF WILDLIFE AND VEGETATIVE

COMMUNITY STUDIES OF DADE COUNTY AND OTHER SELECTED

STUDY AREAS IN SOUTH FLORIDA

ACKNOWLEDGEMENTS

A number of people were instrumental in the completion of this

report: Dr. Richard Gregory, project supervisor, Dr. Franklin Percival,

Ms. Rosi Mulholland and Mr. Terry Hingtgen (Florida Cooperative Fish and

Wildlife Unit); Dr. Kenneth Portier (Department of Statistics,

University of Florida); Dr. William Robertson, Dr. James Kushlan and Mr.

Lance Gundersen (South Florida Research Center, Everglades National

Park); Dr. Ronnie Haynes (USFWS, Atlanta, GA) and Mr. Robert Pennington

(USFWS, Vero Beach, FL).

Access to study sites was provided by Mr. Frank Carroll, Florida Rock

and Sand Company, Inc.; Mr. John Meilbeck, U.S. Department of Justice, Krome

North Processing Center; and Dr. Hetrick, Everglades National Park.

INTRODUCTION

Rock mining in south Florida wetlands is a regulated land use that

alters habitat and thus has potential impact on wildlife. Much of South

Florida lies on a bed of lime rock. The industry that mines this material

was valued at around $1 billion in 1978 (USDI 1979). Historically, lime rock

was mined in the pinelands of the Atlantic coastal ridge. This land is now

developed or in high demand for farming and urban expansion forcing mining

activities westward into the Everglades marshes.

The U.S. Army Corps of Engineers is the principal governmental agency

with jurisdiction for issuing permits for rockmining in wetlands. The U.S.

Fish and Wildlife Service, Division of Ecological Services provides input

during the permitting process by evaluating the potential impact of each

proposed action on fish and wildlife. During this process, mitigative

measures may be recommended, according to the Service's mitigation policy

(Ref-attached). Also, definition of mitigation from mitigation policy may be

recommended. This project was designed to provide background data on

wildlife use of rock mine lakes to aid the Service in identifying alternative

mitigation schemes.

The first phase of this study (Hudy and Gregory 1984), focused on a

survey of the chemical and biotic characteristics of eight rock mine lakes in

south Florida. Sampling included macroinvertebrates, aquatic vegetation, and

fish populations. The overall findings indicated that 1) the oligotrophic

conditions of rock pits limit productivity, 2) macroinvertebrate diversity in

rock pits was low and many important fish food organisms were rare or absent,

and 3) fish densities and condition factors were lower than those found in

natural south Florida systems. The creation of littoral zones, connection of

lakes with adjacent wetlands and replacement of organic matter in lake

sediments were proposed as mitigative measures that would improve the value

of rock mines for fish.

The second phase of this study was designed to meet three objectives: 1)

to quantify and compare wildlife use of a variety of mitigated and

non-mitigated edge types around three rock mines; 2) to examine the features

at each site that enhance wildlife use; 3) to provide an annotated

bibliography.

STUDY AREA

The study area encompasses three mined areas all of which were located

in Dade County, Florida (Fig. 1). The information obtained will also be

relevant for portions of Broward, Monroe, and Collier counties.

Climate and Geography of Dade County

The climate of Dade County is subtropical with alternating wet and dry

seasons. Average yearly temperatures and precipitation recorded during the

period 1951-1975 were 23.20C (73.70F) and 152.42 cm (60.01 in), respectively;

seventy-nine percent of the annual rainfall occurs during May through October

(NOAA 1976).

The topography of Dade County is low and flat with a maximum elevation

of 6.1 m (20 feet) occurring along the Atlantic Coastal Ridge. The porous

limestone bedrock serves as the aquifer which, in the low lying areas, is

connected to the surface waters during the wet season.

natural south Florida systems. The creation of littoral zones, connection of

lakes with adjacent wetlands and replacement of organic matter in lake

sediments were proposed as mitigative measures that would improve the value

of rock mines for fish.

The second phase of this study was designed to meet three objectives: 1)

to quantify and compare wildlife use of a variety of mitigated and

non-mitigated edge types around three rock mines; 2) to examine the features

at each site that enhance wildlife use; 3) to provide an annotated

bibliography.

STUDY AREA

The study area encompasses three mined areas all of which were located

in Dade County, Florida (Fig. 1). The information obtained will also be

relevant for portions of Broward, Monroe, and Collier counties.

Climate and Geography of Dade County

The climate of Dade County is subtropical with alternating wet and dry

seasons. Average yearly temperatures and precipitation recorded during the

period 1951-1975 were 23.20C (73.70F) and 152.42 cm (60.01 in), respectively;

seventy-nine percent of the annual rainfall occurs during May through October

(NOAA 1976).

The topography of Dade County is low and flat with a maximum elevation

of 6.1 m (20 feet) occurring along the Atlantic Coastal Ridge. The porous

limestone bedrock serves as the aquifer which, in the low lying areas, is

connected to the surface waters during the wet season.

Figure 1. Study areas and physiographic provinces (Long and Laketa 1971)

used in this study, Dade County, Florida.

3

Wildlife Habitats of Dade County

Several systems describing the plant associations of this area have been

developed (Davis 1943, Craighead 1971, Long and Laketa 1971, Wade et al.

1980). These systems provide a more in depth classification than found in

Cowardin et al. (1979). The flat topography and high water table of Dade

County create an environment with abrupt changes in the vegetation. This

study uses the five physiographic provinces (Fig. 1) of Long and Laketa

(1971), with an occasional reference to other classification systems as

needed. The five provinces include three wetland types (Everglades, Big

Cypress Swamp, Coastal Marsh and Mangrove Swamp) and two upland types

(Atlantic Coastal Ridge and Sandy Flatlands). The Big Cypress Swamp will be

omitted because it occupies a small portion of Dade County which probably

will not be affected by rock mining. The wetlands that are affected most by

rock mining are Palustrine emergent wetlands (Cowardin et al. 1979).

Wetlands --- The vegetation of the Everglades, a natural drainage

extending from Lake Okeechobee in the north to the coastal mangroves of

Florida Bay in the south, consists of a Palustrine emergent wetland that has

been described by Loveless (1959) (Cowardin et al. 1979). Sawgrass (Cladium

jamaicensis), adapted to both the wet and dry seasons and fire, is the

dominant plant species in the Everglades (Wade et al. 1980). Marshes in this

area contain a variety of plant communities, including pure stands of

sawgrass, cattails (Typha sp.), or a mixture of sawgrass and other sedges,

grasses and aquatic plants, and may be dotted with tree and shrub islands.

The natural drainage that once formed the Everglades has now been

altered by man. The diking of Lake Okeechobee, the creation of water

conservation areas, and south Florida's extensive canal system have altered

the natural flow patterns of this wetland (Wade et al. 1980).

Everglades areas in northeast Dade County are being invaded by Melaleuca

quinquenervia, an exotic tree, which may change the open marsh into an

impenetrable, monotypic forest. These predominately Melaleuca areas are

considered to be of low value to wildlife, though no studies have been

conducted to support this contention.

Long and Laketa (1971) placed both coastal marshes and mangroves into a

single physiographic province. However, since only a small amount of

disturbed mangrove habitat is being impacted by rock mining, this habitat

will not be considered further (see Odum et al. 1982, for a review of this

ecosystem type).

Egler (1952) described the marsh vegetation that occurs in southeast

Dade County as the Southeast Saline Everglades. This habitat covers all the

marshes below the chain of rockland islands extending west through the

Everglades from Florida City to Mahogany Hammock. This region is further

divided by Egler into seven belts of distinct vegetation. Only belts four

and five were considered coastal marshes (Long and Laketa 1975). Belts four

and five are sawgrass prairie which encompasses shrub islands dominated by

Avicennia sp. in Belt four and Rhizphora sp. in Belt five. Casuarina

(Australian pine) is an invader in this habitat type. This area receives

occasional salt water intrusion and heavy saltwater flooding during

hurricanes. Fire maintains the sawgrass community, while the shrub community

dominates in the absence of fire.

Uplands -- Uplands in Dade County are dominated by pines on sites with a

history of periodic fires and tropical hardwood hammocks in the absence of

fire. Both community types contain many plant species that are either

endemic to south Florida or reach the northern limit of their range in this

area. The pinelands are divided into two types; the Sandy Flatwoods in

northeastern Dade County and the Atlantic Coastal Ridge or Rockridge

Pinelands (Fig. 1). The former, found only in the extreme northeast corner

of Dade County, is dominated by the slash pine (Pinus elliottii) with a

ground cover of palmetto (Seronia repens) and wiregrass (Aristida stricta)

(Fig. 1).

The Atlantic Coastal Ridge consists of the limerock ridge along the east

coast and the rock islands in the Everglades which are covered by either

slash pine forests (known as rockland pine forests) or tropical hardwood

hammocks. These tropical forests grow out of the limerock base. The

rockland pine forest supports a more diverse array of plant life than any

other Florida plant community (Loope et al. 1979) including many tropical

species and species endemic to South Florida. With periodic fires, this

plant life remains in the understory of the pineland. In the absence of

fire, this community becomes a tropical hardwood hammock (Wade et al. 1980).

Eighty percent of this habitat type has been eliminated due to urban

development, farmlands, and, to a lesser extent, rock mining. The remainder

has been studied extensively (Robertson 1955, Loope et al. 1979, Gunderson et

al. 1983) and is protected from significant impacts by its location in

Everglades National Park.

Wildlife Of Dade County

Reptiles and amphibians Ninety-two reptile and amphibian species

are found in Dade County including 20 amphibian species, 16 turtle species, 3

crocodilian species, 25 lizard species, and 28 snakes species (Wilson and

Porras 1983). Of the 92, 46 are dependent on wetlands (Duellman and Schwartz

1958). Several species have commercial value: the pig frog is harvested

commercially in the Everglades and supports a small industry which was valued

at $1,125,000 in 1954 (Ligas 1960); the alligator is now harvested as a

nuisance animal, but has a potential recreational and commercial value; the

gopher tortoise and several aquatic turtles are collected locally for food;

the diamond-backed rattlesnake is collected for food, as well as other

products such as venom, skin and rattles; and other amphibians and reptiles

also are collected for sale in the pet industry.

Birds Robertson and Kushlan (1974) reported that of the 296 species

which occur regularly in this area, 40 percent breed locally and the

remainder either migrate through or winter in south Florida. While the

number of land bird species outnumbers that of water birds in this area, the

water birds are the most conspicuous component of the bird community.

The use of south Florida wetlands by wading birds is tied to annual

water level fluctuations (Kushlan 1978, Kushlan 1979, Ogden et al. 1980).

The mixture of permanent coastal wetlands and seasonal freshwater marshes

provides habitat for a large wading bird population (Ogden et al. 1980).

Mammals Thirty-eight mammal species are found in Dade County. Mammals

rely heavily on the mixture of upland and aquatic habitats that provide an

abundance of edge types and seasonally changing habitats. Examples of this

relationship include several species of rodents that rely heavily on the

mixture of upland and aquatic systems, spending the wet season in hammocks

and adjacent pinelands but moving into the marshlands during the dry season

(Bigler and Jenkins 1975, Smith and Vrieze 1979). The mosaic of marsh types

is also important to other species, such as the round-tailed muskrat, which

forage in mixed species marsh but find cover in sawgrass (Tilmant 1975).

Study Sites

Mitigation of rock mines by mine operators in Dade County has been

required only recently; therefore, the number of sites available for study

is limited. Three mines that offered a variety of edge types were selected

for study. At each mine the surrounding natural wetlands were considered to

be a control, while the variety of mine pit edge types were considered

treatments.

Site 1. Homestead Mine

This 44 hectare mine is less than five years old with its mitigated

edges being less than a year old at the time of the study. This site, used

in both phase 1 and phase 2 of this study, is located between U.S. 1 Highway

and Card Sound Road south of Florida City and is within the Coastal Marshes

and Mangrove Swamps physiographic province (Long and Lateka 1971).

Surrounded by raised roads and dikes, it is isolated from adjacent wetlands

(Fig. 2), which consist of sawgrass marsh with shrub islands (Fig. 3) and

stands of Casuarina equisetifolia. The shrub islands on this site consist of

Conocarpus erectus, Ilex cassine, Magnolia virginiana, Myrsine floridana,

Persea borbonia, and Myrica cerifera. The sawgrass marsh is dominated by

sawgrass and Pluchea foetida, Sabatia grandiflora, and Ludwigia sp.

The non-mitigated side (Fig. 4) has a vertical dropoff with very little

shallow (< 1 m) water. This side is still utilized by mining traffic and

Figure 2. Homestead Mine and adjacent land use types in Dade County,

Florida.

9

Figure 3. The Homestead Mine, control area consisting of everglades marsh

being overgrown with tropical hardwood shrubs.

10

Figure 4. The non-mitigated mine edge at the Homestead Mine is characterized

by a row of young Casuarina sp., bare surfaces, and a steep

dropoff at the pond edge.

11

has little vegetation except for a few Casuarina equisetifolia (Australian

pine) established along the mine lake edge.

The mitigated side (Fig. 5) consisted of a series of alternating high

and low shelves along the lake edge. The shelves measured 20 m wide and 50 m

long and alternated between low shelves that are always covered with shallow

( <2 m) water and high shelves that are exposed during the dry season and

covered with shallow (< 0.5 m) water during the wet season. The low shelves

were currently covered during sampling in a single species of submerged

aquatic plant (not identified); the high shelves were sparsely covered in

Typha sp., Sagittaria sp., Panicum hemitomon, and Rhynchospora sp.

Site 2. Krome Avenue

The Krome Avenue mine (about 2.9 ha) (Fig. 6) was 20 years old and was

surrounded by a control area that consisted of Everglades (Fig. 7) dominated

by sawgrass and Melaleuca with occasional patches of cattail. Occasional

domes of mature Melaleuca were scattered through the site. This wetland will

eventually become a solid stand of Melaleuca.

The non-mitigated edge at this site was elevated and separated the pond

from the adjacent marsh (Fig. 8). The pond edge was surrounded by a shallow

zone of Juncus sp. about a meter wide. The remainder of the edge was a thick

forest of Melaleuca and Casuarina.

The mitigated edges (Fig. 9) were two years old and were sloped from the

top of the adjacent peat down to the bed rock, a distance of 50 m, at the

mine edge. They are exposed during the dry season, but were covered with up

to 1 m of water during the wet season. The mitigated areas at this site were

directly connected with the natural wetlands during the wet season.

Figure 5. The mitigated edge, at the Homestead Mines is characterized by

alternating high and low shelves (20 m x 50 m) with the high

shelves flooded during the wet season and exposed during the dry

season.

13

Figure 6. Krome Avenue mine and adjacent land uses, Krome North Processing

Center, Dade County, Florida.

14

Figure 7. The control area at the Krome Avenue mine, a sawgrass marsh with

invading Melaleuca sp.

15

Figure 8. The non-mitigated mine edge at the Krome North Processing Center

was characterized by a dense stand of Casuarina sp. and Melaleuca

sp. and a steep dropoff at the pond edge.

16

Because this site is near ( <1 km) the southern edge of Conservation Area 3,

it remained wet longer into the dry season than the other two sites sampled.

The mitigated edges were vegetated by a series of marsh types. Areas

adjacent to the natural wetlands were covered in cattails (Typha sp.),

followed by needle rush (Juncus sp.) and mudflat or open water, depending on

the season, occurring near the mine edge.

Site 3. Sisal Pond

Sisal Pond is a small (4.3 ha) rock mine located in Everglades National

Park (Fig. 10) and was created in 1957 to provide fill for the road to

Flamingo, Florida. The natural (control) wetlands surrounding Sisal Pond

were a mixed-species marsh dominated by sawgrass (Fig. 11). Burned-over

shrub islands consisted of various tropical hardwoods or slash pine (Pinus

elliottii), and palmetto (Serenoa repens) was scattered throughout this

marsh.

The pond edges at this mine consisted of rip-rap with a 2-m dropoff.

The non-mitigated edge (Fig. 12) has a low berm covered with scattered

tropical shrubs and trees including wild tamarind (Lysiloma latisliquum), red

bay, Myrsine, wax myrtle, and poison wood (Metopium toxiferum), which had

invaded from an adjacent hardwood hammock. The mitigated pond edge lacked a

berm and was connected with the adjacent Everglades (Fig. 13). Vegetation

along the mitigated edge was similar to that in the control, except that it

contained a higher density of shrubs.

Figure 9. The mitigated mine edge (shown here during the dry season) at the

Krome North Processing Center is characterized by sloping edges

and connection with the adjacent marsh.

18

Figure 10. Sisal Pond and adjacent land uses, Everglades National Park, Dade

County, Florida.

19

Figure 11. The control area at Sisal Pond, a natural everglades marsh.

20

Figure 12. The non-mitigated edge at Sisal Pond is characterized by a raised

berm which prevents connection with adjacent wetlands.

21

Figure 13. The mitigated edge at Sisal Pond is characterized by a dropoff

during the dry season a direct and connection with adjacent

wetlands when the water riges in the wet season.

22

METHODS

Vegetation Sampling

The structural components of the vegetation along each transect were

sampled using a nested plot design. Six 10 meter square plots were sampled

along each transect using the whole plot to sample tree density, one quarter

of the plot (5m2) for shrubs, and 10.25 m2 plots for ground cover. Canopy

cover was measured as present or absent at ten randomly selected points in

each plot.

Wildlife Survey Techniques

Breeding and wintering bird populations were surveyed using a strip

transect method (Ralph 1981). Fixed distant counts were made during the

winter and spring along three transects (mitigated, non-mitigated and

control) at each mine (Table 1). Ten counts were made along each transect

between 23 January and 26 February 1984 and 12 counts between 15 April and 25

May 1984. All counts were made within the first three hours of sunlight, the

period when birds are most active (Shields 1977).

Low bird densities prevented the use of statistical tests. Therefore,

descriptive statistics, such as a similarity index and diversity index were

used to compare treatments. It is important to note that these indices

provide comparisons but do not allow a statement regarding probabilities of

differences.

The Morisita's similarity index (Morisita 1959), a valid measurement of

community similarity (Smith and Zaret 1983), was used to compare bird use

between mitigated and non-mitigated edges, and to compare these communities

METHODS

Vegetation Sampling

The structural components of the vegetation along each transect were

sampled using a nested plot design. Six 10 meter square plots were sampled

along each transect using the whole plot to sample tree density, one quarter

of the plot (5m2) for shrubs, and 10.25 m2 plots for ground cover. Canopy

cover was measured as present or absent at ten randomly selected points in

each plot.

Wildlife Survey Techniques

Breeding and wintering bird populations were surveyed using a strip

transect method (Ralph 1981). Fixed distant counts were made during the

winter and spring along three transects (mitigated, non-mitigated and

control) at each mine (Table 1). Ten counts were made along each transect

between 23 January and 26 February 1984 and 12 counts between 15 April and 25

May 1984. All counts were made within the first three hours of sunlight, the

period when birds are most active (Shields 1977).

Low bird densities prevented the use of statistical tests. Therefore,

descriptive statistics, such as a similarity index and diversity index were

used to compare treatments. It is important to note that these indices

provide comparisons but do not allow a statement regarding probabilities of

differences.

The Morisita's similarity index (Morisita 1959), a valid measurement of

community similarity (Smith and Zaret 1983), was used to compare bird use

between mitigated and non-mitigated edges, and to compare these communities

METHODS

Vegetation Sampling

The structural components of the vegetation along each transect were

sampled using a nested plot design. Six 10 meter square plots were sampled

along each transect using the whole plot to sample tree density, one quarter

of the plot (5m2) for shrubs, and 10.25 m2 plots for ground cover. Canopy

cover was measured as present or absent at ten randomly selected points in

each plot.

Wildlife Survey Techniques

Breeding and wintering bird populations were surveyed using a strip

transect method (Ralph 1981). Fixed distant counts were made during the

winter and spring along three transects (mitigated, non-mitigated and

control) at each mine (Table 1). Ten counts were made along each transect

between 23 January and 26 February 1984 and 12 counts between 15 April and 25

May 1984. All counts were made within the first three hours of sunlight, the

period when birds are most active (Shields 1977).

Low bird densities prevented the use of statistical tests. Therefore,

descriptive statistics, such as a similarity index and diversity index were

used to compare treatments. It is important to note that these indices

provide comparisons but do not allow a statement regarding probabilities of

differences.

The Morisita's similarity index (Morisita 1959), a valid measurement of

community similarity (Smith and Zaret 1983), was used to compare bird use

between mitigated and non-mitigated edges, and to compare these communities

Table 1. Sampling regime for each mine used in the Dade County, Florida

rock mine wildlife use study, 1984.

Mine Habitat Type Transect Length Transect

x Width area

Homestead mitigated with a berm 300 m x 50 m 15000 m2

non-mitigated with a berm 600 m x 25 m 15000 m2

sawgrass and shrubs (control) 750 m x 20 m 15000 m2

Krome Ave. mitigated marsh-connected 130 m x 25 m 3250 m2

non-mitigated with a berm 130 m x 25 m 3250 m2

sawgrass and melaleuca 130 m x 25 m 3250 m2

(control)

Sisal Pond mitigated-connected 250 m x 20 m 5000 m2

non-mitigated with a berm 250 m x 20 m 5000 m2

sawgrass marsh (control) 250 m x 20 m 5000 m2

to the adjacent wetland. This index incorporates both a diversity value

(Simpson 1949) and species richness value. Morisita's similarity index

values range from 0 when community composition is totally different between

two communities to around 1.0 when the samples are identical. The

Shannon-Weaver (1949) diversity index was also used as a measure of the

distribution of individuals among species in each community.

In addition to transect sampling, notes were made on the occurrence of

all species or signs of wildlife encountered. These data provide a species

list for each habitat type, but the substrate for track deposition differs in

each habitat; thus, for mammals, these data are not comparable between

habitats.

RESULTS

Vegetation

Homestead Mine The control area is believed to resemble pre-mining

conditions, consisting of a disturbed sawgrass marsh with patches of sawgrass

interspersed with shrub islands and stands of Casuarina. All vegetation

parameters (tree and shrub density and ground and canopy cover) on the

control site greatly exceed those found on both the mitigated and

non-mitigated mine edges (Table 2).

Both edge types are in very early stages of primary succession with the

mitigated edges being sparsely covered by invading wetland species (9% ground

cover). The non-mitigated edges are being invaded by upland species,

principally Casuarina. This species is a characteristic tree of the rim and

diked areas of abandoned rock mines in South Florida.

to the adjacent wetland. This index incorporates both a diversity value

(Simpson 1949) and species richness value. Morisita's similarity index

values range from 0 when community composition is totally different between

two communities to around 1.0 when the samples are identical. The

Shannon-Weaver (1949) diversity index was also used as a measure of the

distribution of individuals among species in each community.

In addition to transect sampling, notes were made on the occurrence of

all species or signs of wildlife encountered. These data provide a species

list for each habitat type, but the substrate for track deposition differs in

each habitat; thus, for mammals, these data are not comparable between

habitats.

RESULTS

Vegetation

Homestead Mine The control area is believed to resemble pre-mining

conditions, consisting of a disturbed sawgrass marsh with patches of sawgrass

interspersed with shrub islands and stands of Casuarina. All vegetation

parameters (tree and shrub density and ground and canopy cover) on the

control site greatly exceed those found on both the mitigated and

non-mitigated mine edges (Table 2).

Both edge types are in very early stages of primary succession with the

mitigated edges being sparsely covered by invading wetland species (9% ground

cover). The non-mitigated edges are being invaded by upland species,

principally Casuarina. This species is a characteristic tree of the rim and

diked areas of abandoned rock mines in South Florida.

Table 2. Vegetation characteristics of 3 rock mines in Dade County,
Florida.

Homestead Mine
(5 years old)

Mitigated Non-Mitigated Adjacent
Parameter edge edge wetlands

Tree Density (#/ha) 0 6 40
Shrub Density (#/ha) 0 6 125
Ground Cover (%) 9 2 24
Canopy Cover (%) 0 0 13

Krome Avenue
( -20 years old)
Mitigated Non-Mitigated Adjacent
Parameter edge edge wetlands

Tree Density (#/ha) 10 90 130
Shrub Density (#/ha) 19521 4400 400
Ground Cover (%) 27 53 26
Canopy Cover (%) 1 15 1

Sisal Pond
( -27 years old)
Mitigated Non-Mitigated Adjacent
Parameter edge edge wetlands

Tree Density (#/ha) 0 0 0
Shrub Density (#/ha) 72 167 0
Ground Cover (%) 68 62 25
Canopy Cover (%) 0 3 0

Krome Avenue Tree density (130 trees/ha) was higher on the control

area than on either mitigated or non-mitigated mine edge types (10 and 90

trees/ha, respectively): however, trees on the berm (non-mitigated sides)

were larger and provided more canopy cover (Table 2). Shrub density, which

included Melaleuca seedlings, was highest in the mitigated area (19,521/ha)

and lowest in the control marsh (400/ha). The percent ground cover was

highest in the upland non-mitigated area (53%) and nearly equal in the

wetland control and non- mitigated edge (27 and 26%, respectively).

Sisal Pond Trees grew along all mine edges and within the control

areas, but distribution was so sparse they did not occur within any of the

sample plots (Table 2). Shrubs were abundant on both the mitigated and

non-mitigated mine edges (72 and 167/ha, respectively) but occurred at low

densities and in scattered clumps in the control area (0/ha). The mitigated

and non-mitigated mine edges had over twice the percent ground cover (62

and 68%, respectively) found in the control area (25%).

Winter Bird Population Study

Homestead Mine The winter bird community found on the control site was

dominated (82% of the species) by non-wetland species (Table 3) while birds

found on the mine edges were mostly those that feed in open wetlands. Of the

17 species recorded in the control site, 8 were associated with the shrub

islands, 3 with large shrubs and trees and 6 species were attracted

to the mixture of shrubs and open sawgrass marsh. The control area (17

species) contained more than three times the number of species recorded on

either the mitigated (4 species) or the non-mitigated (5 species) mine edges.

Table 3. Wintering (15 January 1 March 1984) bird densities, species

richness and diversity on mitigated, non-mitigated and control

sites at the Homestead Mine, Dade County, Florida.

Density (birds/ha)

Species Mitigated Non-Mitigated Control

Killdeer 2.3 2.7
Little Blue Heron .1
American Robin 1.9 .1 .1
Black-bellied Plover .1
Boat-tailed Grackle 2.0
Red-winged Blackbird .2 .1
Palm Warbler .1 .3
Red-bellied Woodpecker .7
Common Yellowthroat 1.1
White-eyed Vireo .9
Gray Catbird .4
Common Flicker .1
Eastern Phoebe .1
Yellow-bellied Sapsucker .1
Northern Cardinal .6
Northern Mockingbird .1
Blue-gray Gnatcatcher .6
House Wren .2
Yellow-rumped Warbler .3
Parula Warbler .1
Swamp Sparrow .1

Total Density (birds/ha)
Species Richness
Species Diversity (H')
% Wetland Species
% Non-wetland species

4.4
4
0.87
75
25

5.1
5
0.98
80
20

5.7
17
2.39
18
82

Species diversity (Table 3) as measured by the Shannon-Weaver formula

was highest in the control area (2.39) followed by the non-mitigated edge

(0.98) and the mitigated edge (0.87).

The killdeer was the most common species in both mine-edge habitat types

but was absent from the control area. Mine edges received little use by

wading birds. The winter bird communities using the mine edge types did not

resemble those found in the control stand, but did resemble each other

(Morisita's index value = .74) (Table 4).

Krome Avenue Winter bird density (89.9 birds/ha), species richness

(10), and diversity (1.76) were highest on the non-mitigated mine edge (Table

5). This raised, forested site attracted a large number of species (60%)

that are considered upland or forest birds and were not found in the open

mitigated edge and control areas (Table 5). The bird communities wintering

in both the mitigated and control areas consisted predominantly of wetland

species. The control site supported the lowest density (3.6 birds/ha)

species richness (3), and diversity (1.01) of any of the three sites. The

species recorded on the control site were the red-winged blackbird, common

yellowthroat and palm warbler. The closest community similarity (Morisita's

index value = .78) occurred between the control site and the mitigated edge

(Table 4).

Sisal Pond Winter bird densities were highest on the mitigated mine

edge; however, species richness and diversity were higher on the

non-mitigated edge (Table 6). The non-mitigated edge supported a lower

percentage of wetland species (28%) than the other two areas. The control

site contained the lowest winter bird density (1.0/ha), species richness (5

species), and diversity (1.61) of the three habitats sampled at this mine.

Table 4. Morisita's (1959) index values for comparing winter bird
communities between mitigated edges, non-mitigated edges and
natural wetlands at 3 limerock mines in Dade County, Florida,
January and February 1984. Values range from 0 (not similar) to 1
(similar).

Homestead Mine

Non-Mitigated Natural
Edge Wetlands

Mitigated Edge .74 .01

Natural Wetland .01

Krome Avenue Mine

Non-Mitigated Natural
Edge Wetland

Mitigated Edge .05 .78

Natural Wetland .37

Sisal Pond

Non-Mitigated
Edge

Natural
Wetland

Mitigated Edge

Natural Wetland

Table 5. Wintering (15 January 1 March 1984) bird densities, species
richness and diversity on mitigated, non-mitigated and control
sites at the Krome Avenue rock mine, Krome Avenue Processing
Center, Dade County, Florida.

Density (birds/ha)

Species Mitigated Non-Mitigated Control

Belted Kingfisher .6 .3
Little Blue Heron .3 .3
Red-shouldered Hawk .3
Red-winged Blackbird 2.5 .3 .6
Common Yellowthroat .6 1.2
Swamp Sparrow .6
Lesser Yellowlegs .9
Common Snipe .3
American Robin .9
American Goldfinch 37.2
Yellow-rumped Warbler 12.4
Blue-gray Gnatcatcher 37.2
Palm Warbler .6 1.8
Boat-tailed Grackle .3
Prairie Warbler .3

Total Density
Species Richness
Species Diversity (H')
1.01
% Wetland Species
% Non-Wetland Species

6.2
8
11.1

87
13

89.9
10
1.76

Table 6. Wintering (15 January 1 March 1984) bird densities, species
richness and diversity on mitigated, non-mitigated and control
sites at Sisal Pond, Everglades National Park, Dade County, Florida.

Density (birds/ha)
Species Mitigated Non-Mitigated Control

Great Blue Heron .6 .2
Swamp Sparrow 1.2 .2
Red-bellied Woodpecker .4
Common Yellowthroat 2.6 .6 .2
Palm Warbler .2 .6
Common Moorhen .2 .2
Sedge Wren .2 .2
Eastern Phoebe .2
Rufous-sided Towhee .2
Red-winged Blackbird 1.2 .2
Green Heron .2 .4
Blue Jay .4
Gray Catbird 1.2
Eastern Meadowlark .2
Northern Cardinal .2
Northern Mockingbird .2
Blue-gray Gnatcatcher .4
White-eyed Vireo .2
American Robin .2
House Wren .4

Total Density (birds/ha)
Species Richness
Species Diversity (H')
% Wetland Species
% Non-wetland Species

7.2
11
1.92
45
55

5.2
24
2.30
28
72

1.0
5
1.61
80
20

Community similarity (Table 4) was closest between the mitigated edge and the

control area (Morisita's index value = .73). The non-mitigated edge with its

prevalence of tropical shrubs and trees supported a winter bird community of

upland species (72%), and therefore had little community similarity with the

mitigated edge type (Morisita's index value = .16) or the control

(Morisita's index value = .13).

Breeding Bird Population Study

Homestead Mine During the breeding season the non-mitigated site

supported the highest density (4.4/ha) of birds (Table 7). This high density

was the result of a single highly abundant species, the killdeer (3.9/ha).

The highest species richness (7 species) and diversity (1.15) occurred in the

control area with the lowest (1 species) occurring on the mitigated area. Of

all the species reported using both mine edges, breeding was confirmed for

only the killdeer.

The breeding bird community using the control area was dominated by

upland shrub and tree dependent species (86%). Only the red-winged blackbird

was found in both the control area and along one mine edge. Because of the

low number of breeding species occurring on the three mine sites, Morisita's

index showed little similarity between breeding bird communities at any of

the mines (Table 8).

Krome Avenue The mitigated mine edge supported higher densities of

breeding birds than the non-mitigated or control edges (Table 9). Species

richness on all sites was low; the two mine edges supported 4 species

each and the control site supported only 2 species. The non-mitigated site

supported predominantly non-wetland species while the mitigated and control

Table 7. Breeding season (15 April 10 May 1984) bird densities, species

richness, and diversity, of mitigated, non-mitigated and control

sites at the Homestead Mine, Dade County, Florida.

Density (birds/ha)

Species Mitigated Non-Mitigated Control

Killdeer 1.0 3.9
Mourning Dove .3
Black-necked Stilt .1
Red-winged Blackbird .1 .3
White-eyed Vireo .3
Rufous-sided Towhee .1
Northern Cardinal .2
Chuck-will's-widow .1
Common Flicker .3
Carolina Wren .1

Density (birds/ha) 1.0 4.4 1.4
Species Richness 1 4 7
Species Diversity 0 1.16 1.15
% Wetland Species 100 75 14
% Non-Wetland Species 0 25 86

Non-breeding migrants also recorded

Red-breasted Merganser
Spotted Sandpiper
Blue-winged Teal

.7
.9 .7
.6

Table 8. Morisita's (1959) index values for comparing breeding bird
communities between mitigated edges, non-mitigated edges and
natural wetlands at 3 limerock mines in Dade County, Florida,
April and May 1984. Values range from 0 (not similar) to 1
(similar).

Homestead Mine

Non-Mitigated Natural
Edge Wetlands

Mitigated Edge .59 0

Natural Wetland .01

Krome Avenue Mine

Non-Mitigated Natural
Edge Wetlands

Mitigated Edge .04 .05

Natural Wetland .19

Sisal Pond

Non-Mitigated Natural
Edge Wetlands

Mitigatd Edge .41 .07

Natural Wetland .10

Table 9. Breeding Season (15 April 10 May, 1984) bird densities, species
richness, and diversity of mitigated, non-mitigated and and
control sites at the Krome Avenue Mine, Dade County, Florida.

Density (birds/ha)
Species Mitigated Non-Mitigated Control

Killdeer 5.2
Red-winged Blackbird .3 .3 .6
Boat-tailed Grackle 1.2
Common Nighthawk .3 .6
Northern Mockingbird .3
Rufous-sided Towhee 1.2
Common Yellowthroat .3

Total Density (birds/ha) 7.0 2.4 .9
Species Richness 4 4 2
Species Diversity (H') 1.03 1.21 .37
% Wetland Species 75 25 100
% Non-Wetland Species 25 75 0

Non-breeding migrants also recorded

Belted Kingfisher .3
Spotted Sandpiper .6

Total Density (birds/ha) .6 .3

sites supported mostly wetland species. The three breeding bird communities

sampled at this mine showed little community similarity.

Sisal Pond The mine edges at Sisal Pond provided habitat for a higher

density, species richness and diversity of breeding birds than did the

control area (Table 10). The mitigated edge had the highest density of

breeding birds (6.6/ha) while the non-mitigated edge supported both higher

species richness (9) and diversity (1.92). Only a single species, the

red-winged blackbird was recorded on the control, which was dry

during the sampling period.

Use of Study Sites by Other Wildlife

In addition to transect counts of bird use of rock mines, non-

quantitative notes were made of all wildlife observed near the mines. These

data are provided only to indicate the range of wildlife using these areas.

Homestead Mine During the period of this study 60 species of birds,

four species of mammals and four species of reptile and amphibians were

encountered at the mine and adjacent control area (Table 11). The close

proximity of the coast to this site attracted several species of coastal

birds not encountered at the other study areas. These included the

black-bellied plover, semipalmated plover, least sandpiper, pectoral

sandpiper, laughing gull, and ring-billed gull. In addition to the habitats

sampled during this study, notes were also made of wildlife use of a stand of

Brazilian pepper adjacent to the mitigated mine edge (Table 11). This plant

species was growing on piles of peat left after preparing the site for

mining. During the winter this habitat contained high densities of American

robins and gray catbirds, which feed on the berries of this plant.

Krome Avenue During visits to this site a total of 48 species of

birds, nine species of reptiles and four species of mammals was observed in

and around the mine site (Table 12). The dense Melaleuca stands on the

non-mitigated edges attracted a variety of wintering upland bird species,

such as American goldfinch, a variety of warblers, the blue-gray gnatcatcher

and others. The mine edges attracted single individuals of a variety of

wading birds.

Sisal Pond During the study 60 species of birds, 9 species of reptiles

and amphibians and 3 species of mammals were recorded at this mine and the

surrounding natural habitats (Table 13). A tropical hammock adjacent to the

non-mitigated edge provided wintering habitat for a variety of species of

birds. The pond itself received casual use by waterbirds as did the pond at

the Krome Avenue site. In general, this mine was the least disturbed of the

three mines surveyed.

DISCUSSION

Wildlife Use Of The Natural Habitats

Winter bird use of the control sites varied between the three mines.

The most disturbed control, Homestead Mine, had the highest species richness

(17 species) and density (5.7 bird/ha), while the least disturbed control,

Sisal Pond, had the lowest density (1.0 bird/ha). The marsh surrounding the

Krome Avenue Mine had fewer wintering species (3) than Sisal Pond (5 species),

but had a higher density (3.6 birds/ha). This variation may be attributable to

alterations in the natural vegetation caused by a variety of factors. At

Krome Avenue, the sawgrass marsh is being invaded by the exotic tree,

Melaleuca sp. The Homestead Mine control is abandoned farmland that returned to

Krome Avenue During visits to this site a total of 48 species of

birds, nine species of reptiles and four species of mammals was observed in

and around the mine site (Table 12). The dense Melaleuca stands on the

non-mitigated edges attracted a variety of wintering upland bird species,

such as American goldfinch, a variety of warblers, the blue-gray gnatcatcher

and others. The mine edges attracted single individuals of a variety of

wading birds.

Sisal Pond During the study 60 species of birds, 9 species of reptiles

and amphibians and 3 species of mammals were recorded at this mine and the

surrounding natural habitats (Table 13). A tropical hammock adjacent to the

non-mitigated edge provided wintering habitat for a variety of species of

birds. The pond itself received casual use by waterbirds as did the pond at

the Krome Avenue site. In general, this mine was the least disturbed of the

three mines surveyed.

DISCUSSION

Wildlife Use Of The Natural Habitats

Winter bird use of the control sites varied between the three mines.

The most disturbed control, Homestead Mine, had the highest species richness

(17 species) and density (5.7 bird/ha), while the least disturbed control,

Sisal Pond, had the lowest density (1.0 bird/ha). The marsh surrounding the

Krome Avenue Mine had fewer wintering species (3) than Sisal Pond (5 species),

but had a higher density (3.6 birds/ha). This variation may be attributable to

alterations in the natural vegetation caused by a variety of factors. At

Krome Avenue, the sawgrass marsh is being invaded by the exotic tree,

Melaleuca sp. The Homestead Mine control is abandoned farmland that returned to

coastal saline everglades marsh and, in the absence of fire, has overgrown with

large patches of tropical shrubs and the exotic tree, Casuarina sp. The Sisal

Pond control was the least disturbed of the three control sites and the only

site with a wintering bird community dominated by wetland species.

The only other wintering bird study conducted in Everglades marsh

(Kushlan and Kushlan 1973) habitat recorded higher species richness (38

species), although density (3.8 birds/ha) was similar to that found in this

study (average for 3 controls 8.3 species 3.1 birds/ha) (Kushlan and Kushlan

1973). The larger number of species recorded in that study was attributable to

a larger survey plot size. Although at first appearance, Everglades marsh

appears to be uniform, a wide variation in both plant density and species

composition exists. Tree and shrub islands, sloughs, gator holes and areas

with slight changes in elevation provide habitat variation and cover that

attract many species (Robertson 1955, Kushlan and Kushlan 1973). The control

site at Sisal Pond consisted of a particularly uniform Everglades marsh with

only a single isolated shrub. This shrub served as a singing perch for the

red-winged blackbird and meadowlark. It also provided cover for the common

yellowthroat, which was recorded only in association with shrub and tree

islands.

Fewer bird species were found on the control sites during the breeding

season than in the winter. The marsh around Sisal Pond had the lowest

species richness (one species) followed by the Krome Avenue control site with 2

species. While the Homestead control supported 7 species of breeding birds,

only the red-winged blackbird is considered a wetland species. The other

species were attracted to the shrub thickets and Casuarina sp.

South Florida, particularly the Everglades, supports fewer breeding

birds than are found in areas to the north (Robertson 1955, Cook 1969,

Kushlan and Kushlan 1973, Robertson and Kushlan 1974). Robertson (1955)

found only two species, the meadowlark and red-winged blackbird, breeding in

sawgrass marsh. However, an additional five species visited the site and the

resulting total density was .35 birds/ha. Kushlan and Kushlan (1974)

surveyed a larger site, found 13 species, of which 10 were nesting in an

Everglades marsh. otal density was .96 birds/ha. Of these two density

estimates for this habitat, Robertson's (1955) was lower and Kushlan

and Kushlan's (1974) was about the same as the three control sites sampled in

this study.

The abundance of shrubs at the Homestead mine may have been the reason

for the increase of all population parameters for both wintering and breeding

birds. However, this increase was caused by the addition to the bird

community of non-wetland species, that do not utilize or depend on wetlands.

Most of the species encountered are habitat generalists and are typically

common in urban settings.

Breeding Season (15 April 10 May 1984) bird densities, species

richness and diversity of mitigated, non-mitigated and control

sites at Sisal Pond, Everglades National Park, Dade County,

Florida.

Density (birds/ha)

Species Mitigated Non-Mitigated Control

Great Blue Heron .2
Cattle Egret .4
Red-winged Blackbird 3.0 .2 .8
Rufous-sided Towhee 1.2 .4
Eastern Kingbird 1.2 .8
Boat-tailed Grackle .2
Red-bellied Woodpecker .2
Common Flicker .2
Northern Cardinal .2
Green Heron .2
Blue Jay 1.0
Common Yellowthroat .2
White-eyed Vireo .2
Limpkin .2

Density (birds/ha)
Species Richness
Species Diversity
% Wetland Species
% Non-Wetland Species

6.6
8
1.51
50
50

3.4
9
1.92
44
56

.8
1
0
100

Table 10.

Habitat relationships of wildlife observed at the Homestead Mine,
(November 1983 to July 1984) Dade County, Florida.

Reptiles and Amphibians

Box Turtle
Cuban Anole
Ribbon Snake
Soft-shelled Turtle

Birds

Double-crested Cormorant
Great Blue Heron
Little Blue Heron
Tricolored Heron
Cattle Egret
Green-backed Heron
Blue-winged Teal
Ring-necked Duck
Red-breasted Merganser
Osprey
Sharp-shinned Hawk
American Kestrel
Black-bellied Plover
Semipalmated Plover
Killdeer
Black-necked Stilt
Greater Yellowlegs
Spotted Sandpiper
Solitary Sandpiper
Least Sandpiper
Pectoral Sandpiper
Laughing Gull
Ring-billed Gull
Least Tern
Mourning Dove
Common Ground-Dove
Common Nighthawk
Chuck-will's-widow
Belted Kingfisher
Red-bellied Woodpecker
Yellow-bellied Sapsucker
Downy Woodpecker
Northern Flicker
Pileated Woodpecker
Eastern Phoebe
Tree Swallow
Purple Martin
American Crow
Carolina Wren
House Wren
Blue-gray Gnatcatcher

C,S
N,M,C
NM
M, NM

M,L
M
M, NM
M
MD
M,S
M
L
M, NM, L
L
S
MD
M
M
M, NM, MD
M, NM
M
M, NM
M
M
M
M
L
M
M, NM, C, MD
M, MD
M, NM, C
C
M
C
C
C
C*
C
C
all
over
M,C
C
C
NM, C, S

Table 11.

Table 11, Continued

Mourning Dove
American Robin
Northern Mockingbird
Brown Thrasher
Cedar Waxwing
White-eyed Vireo
Northern Parula
Yellow-rumped Warbler
Prairie Warbler
Palm Warbler
Northern Waterthrush
Common Yellowthroat
Northern Cardinal
Rufous-sided Towhee
Swamp Sparrow
Red-winged Blackbird
Boat-tailed Gackle
Common Grackle
American Goldfinch

M, NM, C, MD
M, NM, C, MD, S
C, MD
C, MD
C
C,S
C
C
C,S
NM, C

C
C
C
NM, C
NM, C
C
C

Mammals

Oppossum
Raccoon
Bobcat
House Cat

species or reptiles and amphibians
species of birds
4 species of mammals
M = mitigated
NM = non-mitigated
C = control, saline everglades with shrub islands
MD = Man-Dominated, landscaped areas, mining operations
S = Shinus
* = confirmed breeding

Table 12.

Habitat relationships of Wildlife observed at the Krome Avenue
mine (November 1983 to July 1984), Dade County, Florida.

Reptiles and Amphibians

Snapping Turtle
Striped Mud Turtle
Box Turtle
Soft-shelled Turtle
American Alligator
Cuban Anole
Black Racer
Banded Water Snake
Florida Kingsnake

Birds

Pied-billed Grebe
Double-crested Cormorant
Anhinga
Great Blue Heron
Great Egret
Little Blue Heron
Tricolored Heron
Green-backed Heron
Cattle Egret
Wood Stork
Hooded Merganser
Red-shouldered Hawk
Red-tailed Hawk
American Kestrel
Osprey
Killdeer
Black-necked Stilt
Lesser Yellowlegs
Solitary Sandpiper
Spotted Sandpiper
Common Snipe
Mourning Dove
Yellow-billed Cuckoo
Common Nighthawk
Belted Kingfisher
Red-bellied Woodpecker
Yellow-bellied Sapsucker
Northern Flicker
Tree Swallow
Northern Rough-winged Swallow
Barn Swallow
Blue Jay
House Wren
Blue-gray Gnatcatcher
American Robin

P,M
P, NM
NM
M, NM
N, NM
M, NM
M, NM
M
NM
C
P
N, NM, C, MD
C
MD
M, NM, C, P
M*, NM
M
M
M
M
M,C
NM
NM
N, NM, C, MD*
M, NM
NM
NM
NM, C
P
P
P
C
NM
NM, C
NM

Table 12, Continued

Northern Mockingbird
Cedar Waxwing
Loggerhead Shrike
European Starling
Yellow-rumped Warbler
Prairie Warbler
Palm Warbler
Common Yellowthroat
Northern Cardinal
Rufous-sided Towhee
Swamp Sparrow
Red-winged Blackbird
Eastern Meadowlark
Boat-tailed Grackle
Common Grackle
American Goldfinch

Mammals

Raccoon
Bobcat
House Cat
White-tailed Deer

9 species of reptiles
48 species of birds
4 species of mammals

*found nesting in this habitat
M = mitigated edge
NM = non-mitigated edge
C = Control, Everglades Marsh with Melaleuca
MD = Man Dominated
P = rock mine pond

NM, MD
NM
C, MD
MD
NM, C
NM
NM, C, MD
M, NM, C
NM
NM
M,C
M, NM, C*
C
NM, C, MD
NM, C
M, NM

M,C
M, NM, C
C, MD
C

Table 13. Habitat relationships of wildlife observed at the Sisal Pond
(November 1983 to July 1984), Everglades National Park, Dade
County, Florida.

Reptiles and Amphibians

Leopard Frog
Box Turtle
Soft-shelled Turtle
American Alligator
Cuban Anole
Garter Snake
Water Moccasin
Florida Water Snake
Banded Water Snake

NM
C
P
P
C
C
M,C
M, NM
M

Birds

Pied-billed Grebe
Double-crested Cormorant
Anhinga
American Bittern
Great Blue Heron
Great Egret
Snowy Egret
Little Blue Heron
Tricolored Heron
Cattle Egret
Green-backed Heron
Blue-winged Teal
Black-crowned Night Heron
Black Vulture
Turkey Vulture
Osprey
American Swallow-tailed Kite
Northern Harrier
Red-shouldered Hawk
King Rail
Virginia Rail
Common Moorhen
American Coot
Limpkin
Killdeer
Spotted Sandpiper
Caspian Tern
Forster's Tern
Common Barn-owl
Common Nighthawk
Belted Kingfisher
Red-bellied Woodpecker
Northern Flicker
Eastern Phoebe
Eastern Kingbird
Tree Swallow

M,P
P
P
M
M, NM
M, NM, C
C
C
M
M, NM, C
M, NM
P
M
C
over
over
TH, P
C
M, NM, C, TH
C
C
M, NM, P
P
NM
NM
M, NM
P
P
NM
C
M, NM
M, NM, C
M, C
M, C
M, NM, C
over

Table 13, continued.

Barn Swallow
Blue Jay
American Crow
House Wren
Sedge Wren
Blue-gray Gnatcatcher
American Robin
Gray Catbird
Northern Mockingbird
Loggerhead Shrike
White-eyed Vireo
Northern Parula
Yellow-rumped Warbler
Palm Warbler
Black-and-white Warbler
Common Yellowthroat
Northern Cardinal
Rufous-sided Towhee
Swamp Sparrow
Bobolink
Red-winged Blackbird
Eastern Meadowlark
Boat-tailed Grackle
Common Grackle

over
NM, C, TH
NM, C, TH
NM, C
M, C
M, NM, C, TH
NM, C, TH
NM, C, TH
M, NM, C
C
NM, C, TH
TH
C, TH
M, NM, C, TH
TH
M, C, TH
NM
C, NM, C, TH
M, C
C
M, NM, C
M, C
M, C
M

Mammals

Raccoon
White-tailed Deer

M, C
C

9 species of reptiles and amphibians
60 species of birds
2 species of mammals

M = mitigated edge, connected with natural wetland
NM = non-mitigated, raised edge
C = control, sawgrass marsh and hammocks
TH = Tropical Hammock
P = Mine Pond

Wildlife Use of Rock Mines

The open water of the three rock mines surveyed in this study received

little use. The Homestead Mine was both the largest and deepest of the mines

studied. It was sometimes used by terns, gulls, cormorants and several

species of waterfowl; these birds used the lake edges for foraging. The only

species observed in the center of this lake were a raft of ring-necked ducks

and an occasional double-crested cormorant.

Both Sisal Pond and Krome Avenue are small ( 5ha), shallow ( 10

m) ponds that provided habitat for a variety of open-water foragers that

occasionally visited. The Krome Avenue pond was visited regularly by an

osprey, a pair of double-crested cormorants, a great blue heron, and a pair

of pied-billed grebes. Sisal pond was regularly visited by a cormorant and a

great blue heron, and had one resident moorhen.

Wading birds are the most visible group of wetland birds found in the

Everglades areas. This group, which includes herons, egrets, ibises, roseatte

spoonbills, and wood storks, forages on a patchy resource that shifts both

temporally and spatially with changes in regional weather patterns (Kushlan

1976, 1978, 1981). During the dry season, natural sloughs, ponds and gator

holes provide food concentrations and foraging habitat for these species

(Kushlan 1976). None of the mines used in this study attracted the abundance

of wading birds associated with the natural wetlands of the area.

The failure of these man-made lakes and ponds to attract many wetland

birds probably can be attributed to differences in edge types and edge

configurations. Even the mitigated edges offered little variation in

foraging habitat during the dry season. Primary considerations for providing

foraging habitat for wading birds should be to provide both year-round

shallow water (<20 cm) and areas where receeding waters during the dry

season would create isolated pools containing high concentration of prey

species. None of the mitigated edges examined in this study provides a

shallow littoral zone during the dry season. The value of these sites during

the wet season could have been greatly increased by creating year-round

shallow areas to serve as refuges for wading bird prey species.

The non-mitigated edges varied with age and elevation. The bave berms at

the Homestead Mine showed early invasion of the exotic tree Australian Pine

(Casarina sp.). With age this species and if present the Melaluca sp. will

dominate this type of mine edge as seen at the Krome Avenue Mine. The

non-mitigated edges at older Sisal pond did not have exotics dominating

because of the Park Service exotic plant removal program. Removing these

exotics has allowed native hammock vegetation to become established.

In the Everglades, one of the natural functions of year-round wetlands

such as sloughs and alligator holes is to serve as dry season refuges for

fish that forage and breed in the adjacent Everglades marsh during the wet

season (Kushlan 1974). A reasonable mitigation goal applicable to rock mines

should be to improve the value of rock mines for wildlife and to enhance the value

of adjacent natural wetlands. This could occur where mitigation provides

both permanent littoral zones and a connection to the adjacent wetland. At

both Sisal Pond and Krome Avenue, were the mines are connected to the

adjacent wetlands, the bird communities of the mitigated edge were similar to

those found in the adjacent wetland.

The mitigated edges also provided wetland habitat that differed from

that of the adjacent Everglades marsh. Cattail stands were becoming

established on the mitigated marshes of both the Homestead Mine and the Krome

Avenue Mine. Cattails occur naturally in this region in sloughs and at the

edge of gator holes and other depressions in the everglades. Red-winged

blackbirds and boat-tailed grackles nest in higher densities in cattails than

in adjacent sawgrass marshes. On the Krome Avenue mine the sloping mitigated

edge provided varying water depths, which should promote the variety of marsh

types and open foraging habitats required by wading birds.

The non-mitigated edges of many south Florida rock mines quickly become

over-grown in trees and shrubs, usually the exotics, Casuarina sp., Melaleuca

sp. and/or Brazilian pepper. These plants form dense monotypic stands

covering all raised areas surrounding the mine. While these edges do provide

habitat for a variety of upland bird species, they do little to provide

replacement habitat for species found in the pre-mining wetland. The dramatic

difference between the mitigated and non-mitigated edge types at Krome Avenue

indicates that mitigation that provides a littoral zone and a connection with

the natural wetlands does improve the wildlife value of the mine edges for

those species of wildlife occurring in the pre-mining wetland. The mitigated

edge at Sisal Pond was connected to the natural wetland, but did not provide a

littoral zone. While this edge was not used to any great extent by wading

birds, it was used by birds found in the natural wetlands, indicating the

value of connecting mine lakes with the adjacent wetland.

CONCLUSION

Guidelines for Enhancing Wildlife Use of Rock Mines

This study examined two types of mitigation used to improve rock mines

for wildlife; 1) connecting the mine lake to the adjacent wetland and 2)

creating littoral zones along the mine edge. In all cases the non-mitigated

edges did not meet habitat needs for species found in the natural wetland.

In two cases, Sisal Pond and Krome Avenue, the non-mitigated edge supported a

bird community that was more typical of an upland site than a wetland. The

mitigated edges at both these mines were connected to the adjacent marshes

and demonstrated that such mitigation can provide habitat for a bird

community similar to that found in the natural wetlands.

The sloping edges at the Krome Avenue lake and the alternating high and

low cells at the Homestead Mine provided a littoral zone during the wet

season, but failed to provide year-round littoral zone. During the dry

season the water level receded to the mine dropoff at Krome Avenue and fell

below the level of the high cells at the Homestead Mine. The resulting

shallow water cells provided neither wading bird habitat nor shallow water

habitat for small fish (prey species for wading birds). In addition, the

non-sloping nature of the Homestead Mine lake provided only cattail marsh

that was of little value to most wildlife.

This study has demonstrates the value of two mitigation methods, but

also has identifies other considerations for future mitigation projects.

Sloped mitigated edges provide a range of marsh communities and aquatic bird

foraging habitat. Additionally, mine edges should be sloped so that the

deepest portion of the man-made littoral zone will fall below the pond's

lowest seasonal water level. To provide foraging areas for wading birds,

CONCLUSION

Guidelines for Enhancing Wildlife Use of Rock Mines

This study examined two types of mitigation used to improve rock mines

for wildlife; 1) connecting the mine lake to the adjacent wetland and 2)

creating littoral zones along the mine edge. In all cases the non-mitigated

edges did not meet habitat needs for species found in the natural wetland.

In two cases, Sisal Pond and Krome Avenue, the non-mitigated edge supported a

bird community that was more typical of an upland site than a wetland. The

mitigated edges at both these mines were connected to the adjacent marshes

and demonstrated that such mitigation can provide habitat for a bird

community similar to that found in the natural wetlands.

The sloping edges at the Krome Avenue lake and the alternating high and

low cells at the Homestead Mine provided a littoral zone during the wet

season, but failed to provide year-round littoral zone. During the dry

season the water level receded to the mine dropoff at Krome Avenue and fell

below the level of the high cells at the Homestead Mine. The resulting

shallow water cells provided neither wading bird habitat nor shallow water

habitat for small fish (prey species for wading birds). In addition, the

non-sloping nature of the Homestead Mine lake provided only cattail marsh

that was of little value to most wildlife.

This study has demonstrates the value of two mitigation methods, but

also has identifies other considerations for future mitigation projects.

Sloped mitigated edges provide a range of marsh communities and aquatic bird

foraging habitat. Additionally, mine edges should be sloped so that the

deepest portion of the man-made littoral zone will fall below the pond's

lowest seasonal water level. To provide foraging areas for wading birds,

zones of shallow water (< 20 cm) should be provided during all seasons.

Alternating strips of shallow and deep water in mitigated zones during the

wet season should provide isolated pools of aquatic prey for wading birds

during the dry season; these should resemble the natural pools found in

adjacent wetlands.

The uniform high and low cells at the Homestead Mine, while increasing

the land-water interface, provide only two types of habitat: 1) a type of

marsh, and 2) shallow water. If sloping is not feasible, variation in cell

height would create different types of marsh. Also some of the higher cells

could be isolated from the shoreline to create islands of marsh or upland

habitats. This would provide nesting habitat for species such as wading and

shorebirds that require isolation from land based predators, as well as

increasing the land-water interface.

Rock-mine ponds should serve as reservoirs for aquatic species that can

repopulate the adjacent sawgrass marsh at the onset of the wet season, so the

mines should be connected with the natural wetlands. A connection with

natural wetlands would benefit wildlife in both the mine pond and the

surrounding wetlands. Further benefits to wildlife could be accomplished by

digging ditches out from the mine into the adjacent marsh. Ditches of the of

the proper depth, with adjacent littoral zones, could function as natural

sloughs. Some of the existing mine access roads could be dug out to create

these man-made sloughs. This approach would also remove the obstruction

these roads cause to the natural sheet flow of water through the marsh and

also reduce the use of abandoned-mine lakes as dumping sites by limiting

access.

Summary

1. Neither the shallow-sloped shore nor the alternating cell mitigation

methods examined provided year-round littoral zones.

2. The sloping edges of the Krome Avenue mine lake provided a more

variable marsh and temporally more variable habitat than did the

alternating cells at the Homestead Mine.

3. Mitigated edges at the Sisal pond and Krome Avenue lakedid support

bird communities similar to those found in the adjacent marsh, while

the non-mitigated edges supported an upland bird community.

4. Suggested mitigative measures are:

a. providing a sheet flow connection between a mine pond and

the adjacent wetland

b. providing a year-round littoral zone

c. providing habitat variation in the form of nearshore

islands, seasonally wet-dry pools, or channels into

adjacent wetlands

d. reducing or eliminating automobile access to abandoned mine

sites, preferably by removing roads and berms after mining

LITERATURE CITED

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and Business Res. 43 pp.

Bigler, W. J. and J. H. Jenkins. 1975. Population characteristics of

Peromyscus gossypinus and Sigmodon hispidus in tropical hammocks of

south Florida. J. Mamm. 56:633-644.

Cook, R. E. 1969. Variation in species density of North American birds.

Syst. Zool. 18:63-84.

Cowardin, L. M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979.

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Craighead, F. C., Sr. 1971. The trees of south Florida, vol. 1. The

natural environments and their succession. 212 p. Univ. Miami Press,

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Davis, J. H. 1943. The natural features of southern Florida, especially the

vegetation and Everglades. Fla. Geol. Surv. Bull. 25:311.

Duellman, W. E. and A. Schwartz. 1958. Amphibians and reptiles of southern

Florida. Bull. Fla. State Mus. 3(5):181-324.

Egler, F. E. 1952. Southeast saline everglades vegetation, Florida, and its

management. Vegetation Acta Geobotanica 3:213-265.

Gunderson, L., D. Taylor and J. Craig. 1983. Fire effects on flowering and

fruiting patterns of understory plants in pinelands of Everglades

National Park. South Florida Research Center Report, T-547. 37 pp.

Hudy, M. and R. W. Gregory. 1984. Some limnological characteristics of

eight limestone excavations in South Florida. Final report. USFWS.

FWS/OBS-83/34 84p.

Kushlan, J. A. 1974. Observations on the role of the American alligator

(Alligator mississippiensis) in the southern Florida wetlands. Copeia

1974: 993-996.

Kushlan, J. A. 1978. Wading bird use of the east Everglades. Florida Field

Naturalist 6:46-47.

Kushlan, J. A. 1979. Feeding ecology of wading birds. Pages 249-296. in A.

Sprunt IV, J, C. Ogden and S. Wickler (eds.) Wading birds. Nat. Aud.

Soc., New York, NY.

Kushlan, J. A. and M. S. Kushlan. 1976. Winter bird population study, count

63. Am. Birds 30:1066-1067.

Kushlan, J. A. and M. S. Kushlan. 1977. Breeding bird census. Count 144.

Am. Birds 31:83.

Layne, J. N. 1974. The land mammals of south Florida. pp. 386-413. in P.

J. Gleason. (ed.). Environments of south Florida: Present and Past.

Miami geological Society. Memoir 2. 452 pp.

Ligas, F. J. 1960. The everglades bullfrog: life history and management.

Fla. Game and Fresh Water Fish Comm. Fed. Aid Project Report W-29-R.

128 pp.

Long, R. W. and 0. Lakela. 1971. A flora of Tropical Florida. Baryan

Books, Miami, FL. 962 p.

Loope, L. L., D. W. Black, S. Black and G. N. Avery. 1979. Distribution and

abundance of flora in limestone rockland pine forests of Southeast

Florida. South Florida Research Center Report. T-547. 37 pp.

Loveless, C. M. 1959. A study of the vegetation in the Florida Everglades.

Ecology 40:1-9.

Morisita, M. 1959. Measuring of interspecific association and similarity

between communities. Memoirs Faculty Sci. of Kyushu Univ. (Tokoyo)

Series Biology 3:65-80.

NOAA 1976. Climate of Homestead, Florida. Envir. Data Service. Nat.

Climatic Cnt. Asheville, NC. NPN.

Odum, W. E., C. C. Mclvor, and T. J. Smith, III. 1982. The ecology of the

mangroves of South Florida: a community profile. USDI, FWS, 0BS-81/24.

144 p.

Ogden, J. C.,

the Wood

Robertson, W.

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J. A. Kushlan and J. T. Tilmant. 1976. Prey selectivity by

Stork. Condor 78:324-330.

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Florida in relation to the vegetation. Ph.D. dissertation,

Ill. Urbana. 599 p.

Robertson, W. B., Jr. and J. A. Kushlan. 1974. The Southern Florida

Avifauna. in Environments of South Florida: Present and Past. Patrick

J. Gleason, compiler and ed. pp. 414-452. Miami Geo. Soc., Miami, Fla.

Shields, W. M. 1977. The effect of time of day on avian census results.

Auk 94:380-383.

Smith, E. P. and T. M. Zaret. 1982. Bias in estimating niche overlap.

Ecology 63:1248-1253.

Thomas, T. M. 1974. A detailed analysis of climatological and hydrological

records of South Florida with reference to man's influence upon

ecosystem evolution. Pages 82-122 in Gleason, P. 0., Environments of

South Florida: Present and Past. Memoir 2. Miami Geol. Soc. 452 p.

Tilmant, J. T. 1975. Habitat utilization by round-tailed muskrats (Neofiber

alleni) in Everglades National Park. M.S. Thesis. Humboldt St. Univ.,

Arcata, Calif.

U.S.D.I. 1979. Minerals in the economy of Florida. Bur. of Mines.

Washington, D.C. 23 pp.

Wade, D., J. Ewel and R. Hofstetter. 1980. Fire in south Florida

ecosystems. U.S.D.A. For. Serv. Gen. Tech. Report SE-17. 125 pp.

Wilson, L. D. and L. Porras. 1983. The ecological impact of man on the

south Florida herpetofauna. Univ. of Kansas. Spec. Publ. 9. 89 p.

Appendix. Annotated Bibliography of Wildlife and Vegetative Community

Studies of Dade County and Other Selected Study areas in South

Florida

Introduction

This bibliography is designed to provide annotated references on

wildlife and wildlife habitats in Dade County and adjacent portions of south

Florida. A complete review of the literature was beyond the scope of this

project but an attempt was made to include all major references and review

papers.

Habitats and Plants

Avery, G. N. and L. L. Loope. 1980. Endemic Taxa in the flora of south
Florida. South Florida Research Center Report T-558. 39pp.

Sixty-five taxa of plants are listed that are endemic to south
Florida. Only 32 of these endemics occur in the National Park. The
future and conservation of these species is discussed.

Avery, G. N. and L. L. Loope. 1983. Plants of Everglades National Park: a
preliminary checklist of vascular plants. Everglades National Park.
South Florida Research Center. Report T-574. Second edition. 76pp.

This report provides a list of plants found in the park including
exotic species.

Bechtold, W. A. and H. A. Knight. 1982. Florida's Forest. U.S.D.A.,
Southeast For. Exp. Stat. Research Bull. SE-62. 84pp.

Dade County is 1,250,756 acres in size; 16.8% of this area (209, 959
ac) is forested. There are no commercial forests in Dade County.

Egler, F. E. 1952. Southeast saline everglades vegetation, Florida, and its
management. Veg. Acta Geobotanica 3:313-265.

This report provides a description of a distinct sub-category of
everglades marsh lying in southeastern Dade County below Florida City
and the pine ridge extending to Mahagony Hammock. This area differs
from more northern everglades marsh in that it is periodically inundated
by hurricanes which drive salt water over much of this area.

Harper, R. M. 1927. Natural resources of Southern Florida. 18th Annu. Rep.
Fla. Geol. Surv. 206p.

This report provides a classification system and description for the
major plant communities in south Florida. This includes a dominant
plant species list for each community. A short review of the area's
geology, climate and fauna is also presented.

Loope, L. L. 1980. Phenology of flowering and fruiting in plant communities
of Everglades National Park and Biscayne National Monument, Florida.
Everglades National Park. South Florida Research Center. Report T-593.
50p.

Year-round phenology of flowering and fruiting was recorded in
tropical hardwood hammock, pineland, freshwater marsh communities,
mangrove and other saline communities, and secondary succession.

Loope, L. L., D. W. Black, S. Black, and G. N. Avery. 1979. Distribution
and abundance of flora in limestone rockland pine forests of
southeastern Florida. Everglades National Park, South Florida Research
Center. Report T-547. 37pp.

A vegetative characterization of the rockland pine forest is
reported. This habitat type has declined by 80% since 1900, from 75,000
ha to 10,000 ha. Eighty percent of the remaining rockland pine forest
is in the Everglades National Park. Preservation of the remaining
forest is recommended and the need for the use of fire management in
this habitat type is stressed. Endemic species to this habitat type
are discussed and endangered species status recommended for some.

Schomer, N. S. and R. D. Drew. 1982. An ecological characterization of the
lower Everglades, Florida Bay, and the Florida Keys. USDI. FWS. Office
of Biological Services, 0BS-82/58.1, 246p.

Stevenson, G. B. 1969. Trees of Everglades National Park and the Florida
Keys. Published by the author. 32pp.

This book provides descriptions and line-drawings of the trees and
large shrubs of South Florida. It is useful because it includes the
tropical species that are restricted to this area.

Wade, D., J. Ewel, and R. Hofstetter. 1980. Fire in south Florida
ecosystems. USDA, For. Serv., Gen. Tech. Rep. SE-17, 125p. Southeast
For. Exp. Stn. Asheville, NC. 125p.

A review of the effects of fire on south Florida ecosystems with
information on the evasion of the exotic tree, melaleuca into south
Florida natural ecosystems.

Wildlife

A. Reptiles and Amphibians

Babbitt, L. H. and C. H. Babbitt. 1951. A Herpetological study of
burned-over areas in Dade County, Florida. Copeia 1951(1):79.

A description of the effects of fire on reptiles and amphibians
following a fire on the limestone ridge area of Dade County. Both live
and dead specimens of nine species were collected after a fire. Most
box turtles collected had scars of past fires on their shells. This
species avoids fire by burrowing into the soil.

Duellman, W. E. and A. Schwartz. 1958. Amphibians and reptiles of southern
Florida. Bull. Fla. State Mus. 3(5):181-324.

An overview of the 80 species of non-marine reptiles and amphibians
of south Florida (Fort Lauderdale and Naples south to Key West)
presenting species-habitat relationships and species accounts.

Ligas, F. J. 1960. The everglades bullfrog: life history and management.
Fla. Game and Fresh Water Fish Comm. Fed. aid. Project Report W-29-R.
128p.

The everglades bullfrog or pig frog (Rana grylio) breeds year round
in Sloughs and everglades marsh-tree island edges as long as water is
present. This paper reviews the life history of this species and
discusses the commercial harvest.

Steiner, T. M., 0. L. Bass, Jr., and J. A. Kushlan. 1983. Status of the
Eastern Indigo Snake in Southern Florida National Parks and Vicinity.
South Florida Research Center Report SFRC-83/01. 25pp.

A review of past records of occurrence of this species in south
Florida. Habitats used in the Everglades National Park include the
pinelands, hammocks, canal banks, and various marsh habitats. Indigo
snake biology and ecology is also discussed in this paper.

Wilson, L. D. and L. Porras. 1983. The ecological impact of man on the
South Florida herpetofauna. Univ. of Kansas, Mus. of Nat. Hist. special
publ. 9:89 pp.

A review of the man-induced changes of south Florida both habitat
changes caused by development and those caused by introduced plant
species. The effects of these changes on the reptiles and amphibians of
south Florida are reported with a review of exotic species currently
established in south Florida.

B. Birds

Emlen, J. T. 1970. Habitat selection by birds following a forest fire.
Ecology 51:343-345.

Counts of birds during the winter and spring following a forest fire
in the rockland pine forests of Everglades National Park. The main
conclusion is that the fire did not alter the species composition of the
pineland. Winter and breeding bird populations are lumped in this study
so no density data is presented. Twenty-six species of birds were
recorded in this habitat during the study.

Fish, E. J. 1975. Pineland, scrub and residential. Am. Birds 29:770.
This 8.1 ha site is located in Homestead, Dade County, Florida. A
total of 183 (2261/km2) of wintering birds were recorded on this site.
The yellow-rumped warble was the most abundant of the 51 species
recorded. The species present represented a collection of open land,
wetland, woodland, and shrubland birds.

Kahl, M. P., Jr. 1969. Food ecology of the wood stork (Mycteria americana)
in Florida. Ecol. Monogr. 34:97-117.

This study examines the relationship of water levels to wood stork
foraging and breeding habitat. Fish were found to be the major food
item of the wood stork in south Florida.

Kushlan, J. A. 1973. Least bittern nesting colonially. Auk 90:685-686.

Least bittern, boat-tailed grackle, common moorhen, king rail,
red-winged blackbird, and green-backed heron are reported nesting in
sawgrass strands, 2 meters high, in the Shark River Slough of Everglades
National Park. A unusually high density of least bitterns (423
nests/ha.) in one sawgrass strand is reported. Other strands in the
area supported from 0 to 3 nests/ha. This high density was believed to
be caused by optimal foraging habitat, recently burned sawgrass, being
found nearby. The literature is reviewed and least bittern nesting
densities are presented for other areas, ranging from 0.06 to 18.5
nests/ha with individual studies also reporting 1.0, 1.1, 1.7, 1.8, and
5.1 nests/ha.

Kushlan, J. A. and 0. L. Bass. 1983. The snail kite in the southern
Everglades. Fla. Field. Naturalist 11:108-111.

A review of recent and historical sightings of this species south of
U.S. 41. Outside the National Park sightings are reported in portions
of the Shark River Slough east of the park and in coastal marshes south
of Florida City and west of U.S. 1.

Kushlan, J. A., 0. L. Bass, Jr., L. L. Loope, W. B. Robertson, Jr., P. C.
Rosendahl, and D. L. Taylor. 1982. Cape Sable Seaside Sparrow
Management Plan. South Florida Research Center Report M-660. 37pp.

A review of the status of this endangered subspecies is presented.
It's current range in Dade County is within the Everglades National Park
and in areas east of the park between SR 27 and the Park north of
Florida City and US 1 and the Park south of Florida City. The species
inhabits inland marshes and flooded prairies.

Kushlan, J. A. and M. S. Kushlan. 1977. Everglades Marsh. Breeding Bird
Census. Count 144. Am. Birds 31:83.

Thirteen species were reported from a 44.6 ha study plot in the
Everglades National Park, Dade County. A total density of 96 pairs/km2
was estimated for this habitat type. Ten species of the 13 were
reported breeding. They include the green heron (14 pairs),
red-winged blackbird (8), common yellowthroat (7), boat-tailed grackle
(5), tricolored heron (2), cardinal (2), Carolina wren (2), Anhinga (1),
king rail (1), purple gallinule (1), red-shouldered hawk, limpkin, and
barred owl.

Kushlan, J. A., 0. L. Bass, Jr., and L. C. McEwan. 1982. Wintering
waterfowl in Everglades National Park. South Florida Research Center.
Report T-670. 26pp.

This paper reviews wintering waterfowl population data for Everglades
National Park along the gulf coast. Six species make up 90% of the
wintering duck population recorded in the park: blue-winged teal
(41.4%), Lesser Scaup (23.6%), Pintail (18.5%), American wigeon (9.2%),
ring-necked duck (4.6%) and the northern shoveler (2.5%). A three year
mean (1979-1980) of ducks and coots wintering in the park as 25,500
6,700 (x 50) ducks and 27,800 6,100 coots. The majority of these
winter in western Dade County and eastern Monroe County, the sections of
the park in southeastern Dade County supported few waterfowl.

Moseley, L. H. 1978. Suburban School Park. Am. Birds 32:47.
This is the last of 9 years of counts of winter birds using a
residential area in Deerfield Beach, Broward County, Florida. A
wintering bird density of 300 birds/km2 (16 species) was recorded on
this 8 ha plot. Species encountered and densities (birds/km2) were
mourning dove (162), rock dove (50), mocking bird (25), house sparrow
(25), American kestrel (12) and additional 11 species were recorded at
low densities.

Nesbitt, S. A., J. C. Ogden, H. W. Kale, II., B. W. Patty, and L. A. Rowse.
1982. Florida atlas of breeding sites for herons and their allies:
1976-78. U.S. Fish and Wildlife Service, Office of Biological Services.
FWS/OBS-81/49. 449p.

Owre, 0. T. 1973. A consideration of the exotic avifauna of southeastern
Florida. Wilson Bull. 85:491-500.

This paper reviews the exotic avian species that can be found in
south Florida. These species occur mainly in the cities where they use
exotic plants for food and cover. Several species are mentioned as
being possible pests to the fruit and vegetable crops grown in this area
if their populations grow.

Patterson, G. A., W. B. Robertson, Jr, D. E. Minsky, L. Gunderson and R.
Rochefort. 1980. Slash Pine-cypress Mosaic. pages 61-62. in Van
Velzen, W. T. (ed.) 43rd breeding bird census. Am. Birds 34(1-:41-106.

The slash pine-cypress mosaic habitat in Collier County adjacent to
the everglades were censused. Eighteen species of breeding birds were
observed on a 40 ha plot with a total density of 48.5 territorial males
(121/km2, 49/100 acres). Densities (no. males/km2) for each species
was: red-bellied woodpecker (18), great crested flycatcher 15, Carolina
wren (15), pine warbler (15), bobwhite (10), Cardinal (8), and densities
of less than 5 males/km2 of an additional 12 species.

Robertson, W. B., Jr., L. L. Breen, and B. W. Patty. 1983. Movement of
marked roseate spoonbills in Florida with a review of present
distribution. J. Field Ornithol. 54:225-236.

A review of the current distribution of this species.

Sykes, P. W., Jr. 1983. Recent population trend of the snail kite in Florida
and its relationship to water levels. J. Field Ornithol. 54:237-246.

Sykes, P. W., Jr. 1983. Snail kite use of freshwater marshes of South
Florida. Florida Field Naturalist 11:73-88.

An outline of the recent distribution trends for the Snail Kite in
south Florida including maps of localities. This report states that
there has been a 49% decline in kite habitat in this region. The future
of this species in this area will be assured only through water
management geared exclusively for this species. It is suggested that
this type of management would also benefit other everglades wildlife.

Vernick, K. and D. L. Taylor. 1981. Breeding bird census. Cutover
subtropical slash pine forest. Am. Birds 35:67-70.

This site is located in Everglades National Park, Dade County,
Florida, it is a 20.24 ha study plot that was logged before 1947. A
total of 13 species were recorded on the site with a density of 84
pairs/km2. The species present included pine warbler (7 pairs),
red-bellied woodpecker (5), downy woodpecker (2), blue jay (2), Carolina
wren (0.5), white-eyed vireo (0.5), northern bobwhite,
chuck-wills-widow, common nighthawk, pileated woodpecker, great crested
flycatcher, cardinal and rufous-sided towhee.

C. Mammals

Bigler, W. J. and J. H. Jenkins. 1975. Population characteristics of
Peromyscus gossypinus and Sigmodon hispidus in tropical hammocks of
South Florida. J. Mammal. 56:633-644.

This study was conducted near Pinecrest, Monroe County, Florida in
tropical hammock islands in the Everglades. The most common rodent in
the hammocks was P. gossypinus which occurred at densities of 27-96
individuals/hectare. The cotton rat (S. hispidus) was common in the
adjacent sawgrass and only entered the hammocks during periods of high
water. One black rat (Rattus rattus) was also caught during the study
and rice rats (Oryzomys palustris) were common along nearby canal edges
but not found in the hammock.

Mazzotti, F. J., W. Ostrenko, and A. T. Smith. 1981. Effects of the exotic
plants Melaleuca quinquenervia and Casuraina equisetifolia on small
mammal populations in the eastern Florida Everglades. Fla. Sci.
44:65-71.

Three species were studied (Peromyscus gossypinus, Sigmodon hispidus,
and Oryzomys palustris) in native Cocoplum hammocks and hammocks of
Casuarina or Melaleuca. Casuarina habitats supported the fewest
rodents. Peromyscus favoured the interior of Melaleuca hammocks.
Oryzomys and Sigmodon occurred in mixed Melaleuca-graminoid habitats.
Both Peromyscus and Sigmadon were residents in the stands where they
occurred. Oryzomys used these habitats seasonally.

Smith, A. T. 1980. An environmental study of Everglades mink (Mustela
vison). Everglades National Park, South Florida Research Center.
Report T-593. 17pp.

This study was conducted on Everglades mink on US 41 in Dade County.
Road killed specimens and sight records are reported. Trapping for mink
proved unsuccessful, though sign was plentiful along canal and levee
edges. The majority of the sightings and specimens were from US 41
between SR 27 and the Shark Valley River tram including canal L67.
Everglades mink were found to feed on crayfish, fish, small mammals, and
unidentified insects.

Smith, A. T. and D. M. Cary. 1982. Distribution of Everglades Mink. Fla.
Sci. 95:106-112.

A presentation on data indicating the Everglades mink is found in the
everglades marsh along the Tamiami Trail (US41). All sightings were
along roadways or levees. This paper does not indicate whether this
species does occur in areas in the everglades absent of human
disturbance.

Smith, A. J. and J. M. Vrieze. 1979. Population structure of Everglades
rodents: responses to a patchy environment. J. Mammal. 60:778-794.

Small mammal populations on 6 tropical hammock tree islands in the
everglades of Dade County were studied. Densities of teh three species
recorded; (Peromyscus gossypinus, Sigmodon hispidus and Oryzomys
palustris, averaged 117/ha, 53/ha and 31/ha, respectively. Peromyscus
gossypinus spent the entire year in the hammocks but also traveled
between hammocks. Sigmodon hispidus and Oryzomys palustris both
occurred in the hammocks during the wet season. During the dry season
Sigmedon hispidus utilized the sawgrass while the Oryzomys palustris
left the area. All three species bred in the hammocks during the dry
season.

Tilmant, J. T. 1975. Habitat utilization by round-tailed muskrats (Neofiber
alleni) in Everglades National Park. M.S. Thesis. Humbolt State
University, Arcata, California. 91pp.

This species is most common in maidencane marshes and to a lesser
extent Typha marshes. Active houses were not found in water deeper than 66
cm. Sawgrass was used for cover only when habitats with sufficient food
resources occurred nearly, such as Eleocharis prairies, which provide food
but lack sufficient cover. Density of round-tailed muskrat houses ranged
from: a low of 7.1 houses/ha in sawgrass to a high of 142.9 houses/ha in the
maidencane marsh.

MILLISECOND	CLASS.METHOD	MESSAGE
0	sobekcm_page_globals.constructor
0	sobekcm_page_globals.constructor	Application State validated or built
0	sobekcm_database.verify_item_lookup_object
0	sobekcm_page_globals.constructor	Navigation Object created from URI query string
0	sobekcm_database.verify_item_lookup_object
0	sobekcm_page_globals.display_item	Retrieving item or group information
0	sobekcm_page_globals.get_entire_collection_hierarchy	Retrieving hierarchy information
0	sobekcm_assistant.get_entire_collection_hierarchy
0	cached_data_manager.retrieve_item_aggregation
0	cached_data_manager.retrieve_item_aggregation	Found item aggregation on local cache
0	item_aggregation_builder.get_item_aggregation	Found 'all' item aggregation in cache
0	system.web.ui.page.page_load (ufdc.page_load)
0	sobekcm_page_globals.constructor.on_page_load
0	html_echo_mainwriter.add_style_references	Adding style references to HTML
0	html_echo_mainwriter.add_text_to_page	Reading the text from the file and echoing back to the output stream
84	html_echo_mainwriter.add_text_to_page	Finished reading and writing the file