<%BANNER%>

Space Use, Habitat and Nest-Site Selection by Northern Bobwhites in South Florida

Permanent Link: http://ufdc.ufl.edu/UFE0024462/00001

Material Information

Title: Space Use, Habitat and Nest-Site Selection by Northern Bobwhites in South Florida
Physical Description: 1 online resource (65 p.)
Language: english
Creator: Singh, Aditya
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2009

Subjects

Subjects / Keywords: bobwhite, habitat, nesting
Wildlife Ecology and Conservation -- Dissertations, Academic -- UF
Genre: Wildlife Ecology and Conservation thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: The manner by which animals use space and select resources can have important management consequences. Harvest records indicate that the northern bobwhite quail (Colinus virginianus) population in Babcock-Webb Wildlife Management Area in Charlotte County, Florida, USA has been declining steadily since the 1970's. This decline has occurred despite the economic importance of the northern bobwhite as a game species and extensive efforts to maintain and improve its population welfare. Using data from radio-tagged bobwhites monitored from 2002-2007 at the Babcock-Webb Wildlife Management Area, I examined factors influencing home-range dynamics, habitat and nest-site selection, and the relation of nest success with landscape composition and structure surrounding nest sites. The mean (plus or minus 1 SE) annual home range size, estimated using the Kernel density method, was 88.43 (plus or minus 6.16) ha, and did not differ between genders. Winter home ranges of bobwhites (69.27 plus or minus 4.92 ha) were generally larger than summer home ranges (53.90 plus or minus 4.93 ha). Annual and winter home ranges were smaller for bobwhites whose ranges contained food plots, compared to those that did not; however, the presence of food plots did not influence summer home ranges. Using a distance-based method, I investigated habitat selection by bobwhites within home ranges. Bobwhites preferred food plots, pine palmetto and dry prairie habitats, and avoided wet prairies and roads grades. This pattern was generally consistent between genders and across years. There was also strong evidence that bobwhites exhibited nesting habitat selection. Bobwhites preferred to establish nests closer to food plots (P < 0.0001) and farther away from water bodies (P = 0.0003); other habitat types were neither preferred nor avoided. Habitat composition and landscape features differed between random points and nest-sites, and landscape features that quantified connectedness and diversity significantly influenced the probability of nesting on a given site. Of a total of 365 nests monitored, only 208 (56.99%) were successful. Nesting success did not differ among habitat types, and none of the habitat and landscape variables we measured significantly influenced the probability of nesting success. These results suggest that random nest predation by meso-mammalian predators, rather than habitat variables, may ultimately determine fates of bobwhite nests in south Florida. The results also provide further evidence for the importance of food plots.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Aditya Singh.
Thesis: Thesis (M.S.)--University of Florida, 2009.
Local: Adviser: Oli, Madan K.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2011-05-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2009
System ID: UFE0024462:00001

Permanent Link: http://ufdc.ufl.edu/UFE0024462/00001

Material Information

Title: Space Use, Habitat and Nest-Site Selection by Northern Bobwhites in South Florida
Physical Description: 1 online resource (65 p.)
Language: english
Creator: Singh, Aditya
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2009

Subjects

Subjects / Keywords: bobwhite, habitat, nesting
Wildlife Ecology and Conservation -- Dissertations, Academic -- UF
Genre: Wildlife Ecology and Conservation thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: The manner by which animals use space and select resources can have important management consequences. Harvest records indicate that the northern bobwhite quail (Colinus virginianus) population in Babcock-Webb Wildlife Management Area in Charlotte County, Florida, USA has been declining steadily since the 1970's. This decline has occurred despite the economic importance of the northern bobwhite as a game species and extensive efforts to maintain and improve its population welfare. Using data from radio-tagged bobwhites monitored from 2002-2007 at the Babcock-Webb Wildlife Management Area, I examined factors influencing home-range dynamics, habitat and nest-site selection, and the relation of nest success with landscape composition and structure surrounding nest sites. The mean (plus or minus 1 SE) annual home range size, estimated using the Kernel density method, was 88.43 (plus or minus 6.16) ha, and did not differ between genders. Winter home ranges of bobwhites (69.27 plus or minus 4.92 ha) were generally larger than summer home ranges (53.90 plus or minus 4.93 ha). Annual and winter home ranges were smaller for bobwhites whose ranges contained food plots, compared to those that did not; however, the presence of food plots did not influence summer home ranges. Using a distance-based method, I investigated habitat selection by bobwhites within home ranges. Bobwhites preferred food plots, pine palmetto and dry prairie habitats, and avoided wet prairies and roads grades. This pattern was generally consistent between genders and across years. There was also strong evidence that bobwhites exhibited nesting habitat selection. Bobwhites preferred to establish nests closer to food plots (P < 0.0001) and farther away from water bodies (P = 0.0003); other habitat types were neither preferred nor avoided. Habitat composition and landscape features differed between random points and nest-sites, and landscape features that quantified connectedness and diversity significantly influenced the probability of nesting on a given site. Of a total of 365 nests monitored, only 208 (56.99%) were successful. Nesting success did not differ among habitat types, and none of the habitat and landscape variables we measured significantly influenced the probability of nesting success. These results suggest that random nest predation by meso-mammalian predators, rather than habitat variables, may ultimately determine fates of bobwhite nests in south Florida. The results also provide further evidence for the importance of food plots.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Aditya Singh.
Thesis: Thesis (M.S.)--University of Florida, 2009.
Local: Adviser: Oli, Madan K.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2011-05-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2009
System ID: UFE0024462:00001


This item has the following downloads:


Full Text

PAGE 1

1 SPACE USE, HABITAT AND NEST SITE SELECTION BY NORTHERN BOBWHITES IN SOUTH FLORIDA By ADITYA SINGH A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE D EGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2009

PAGE 2

2 2009 Aditya Singh

PAGE 3

3 To Akshara

PAGE 4

4 ACKNOWLEDGMENTS This project would not have been possible without the help and support of numerous people and org anizations. First and foremost, I would like to thank the members of my graduate committee, Dr. Madan Oli, Dr. Franklin Percival and Tommy Hines. I am indebted to Dr. Franklin Percival and Tommy Hines for agreeing to serve on my committee in some very diff icult circumstances. I am indebted for this thesis and my graduate school experience to my Advisor, Dr. Madan Oli. His passion for the field of conservation biology and expertise in quantitative population ecology has seen me through some very challenging moments. Dr. Ralph W. Dimmick deserves special mention for the successful completion of this project, I am grateful for his support throughout the progress of this project. Many thanks to A. Brinkley, G. Coker, C. McKelvy, D. Caudill, S. Dimmick, D. Holt, J. McGrady, J. Sloane, J. Scott, and L. Taylor for data collection on the field. T im provided valuable advice throughout the study. We are grateful to the many volunteers from the Southwest Florida Chapter of Quail Unlimited who aided the research in many ways. Research for the project was funded by the Florida Fish and Wildlife Conservation Commission, and the Department of Wildlife Ecology and Conservation and School of Natural Resources and the Environment, University of Florida. I would like t o extend my sincere gratitude to Dr. Susan Jacobson and the selection committee of the Louis Anthony Dexter fellowship for providing supplemental funding in my first year at the University. I am also grateful to the Graduate School of the University of Flo rida for continued support via the Grinter graduate student award. My special thanks to Dr. Stephen Humphrey, Director of the School of Natural Resources and the Environment (SNRE) for tuition and funding support throughout my graduate studies Many thank s to the staff at SNRE and the Department of Wildlife Ecology and Conservation,

PAGE 5

5 especially Cathy Ritchie, Meisha Wade, Elaine Culpepper and Claire Williams for helping with my transition to the Department of Wildlife Ecology and Conservation. I wish to ext end my heartfelt gratitude to Dr. Stephen Humphrey, Director SNRE and Dr. John Hayes, Director Department of Wildlife Ecology and Conservation for their understanding, help and empathy in some very difficult moments of my career. My stay at the Universit y of Florida was made memorable by the help and support of all members of the Oli lab; Dr. Arpat Ozgul, Jeffrey Hostetler, Kristen Aaltonen, Saif Nomani, Chris Rota and Gail Morris. This acknowledgment would be incomplete without the mention of my colleagu es at the School of Forestry, especially Milind Bunyan and Puneet Dwivedi and all friends at the Corry Village. I t was my Father who inspired me to follow my heart and stood by me in all career decisions and m y Mom let me find my own way out of the rat rac e. Lastly, i t would not be an understatement if I said I would not have gotten anywhere in my career without the unflagging support and understanding of my wife Preety and the patience of Akshara, my daughter, at the long hours I spent away from home

PAGE 6

6 TA BLE OF CONTENTS page ACKNOWLEDGMENTS ................................ ................................ ................................ ............... 4 LIST OF TABLES ................................ ................................ ................................ ........................... 8 LIST OF FIGURES ................................ ................................ ................................ ......................... 9 ABSTRACT ................................ ................................ ................................ ................................ ... 10 CHAPTER 1 INTRODUCTION ................................ ................................ ................................ .................. 12 2 PATTERNS OF SPACE AND HABITAT USE BY NORTHE RN BOBWHITES IN SOUTH FLORIDA ................................ ................................ ................................ ................. 14 Introduction ................................ ................................ ................................ ............................. 14 Study Area and Methods ................................ ................................ ................................ ........ 16 Study Area ................................ ................................ ................................ ....................... 16 Trapping and Radio Telemetry ................................ ................................ ....................... 17 Data Analysis ................................ ................................ ................................ ................... 18 Results ................................ ................................ ................................ ................................ ..... 21 Annual Home Ranges ................................ ................................ ................................ ...... 21 Seasonal Home Ranges ................................ ................................ ................................ ... 22 Habitat Selection ................................ ................................ ................................ ............. 23 Discussion ................................ ................................ ................................ ............................... 24 3 THE INFLUENCE OF NEST SITE SELECTION ON BOBWHITE NESTING SUCCESS IN SOUTH FLORIDA ................................ ................................ ......................... 36 Introduction ................................ ................................ ................................ ............................. 36 Study Area ................................ ................................ ................................ .............................. 37 Methods ................................ ................................ ................................ ................................ .. 38 Trapping and Radio Telemetry ................................ ................................ ....................... 38 Nest Locations and Nesting Success ................................ ................................ ............... 38 Testing for Nest Sit e Selection ................................ ................................ ........................ 39 Quantification of Landscape Structure and Composition ................................ ............... 41 Testing for the Effect of Landscape Composition and Stru cture on Nest Site Selection and Nesting Success ................................ ................................ ..................... 42 Results ................................ ................................ ................................ ................................ ..... 42 Nest Site Selection ................................ ................................ ................................ ........... 42 Effect of Habitat Composition and Structure on Nest Site Selection ............................. 42 Factors Influencing Nesting Success ................................ ................................ ............... 43 Discussion ................................ ................................ ................................ ............................... 44

PAGE 7

7 4 CONCLUSIONS AND MANAGEMENT RECOMMENDATIONS ................................ ... 53 Conclusions ................................ ................................ ................................ ............................. 53 Management Recommendations ................................ ................................ ............................. 55 LIST OF REFERENCES ................................ ................................ ................................ ............... 57 BIOGRAPHICAL SKETCH ................................ ................................ ................................ ......... 65

PAGE 8

8 LI ST OF TABLES Table page 2 1. Description of habitat types represented and area occupied by each habitat type in Babcock Webb Wildlife Management Area, Florida. ................................ ....................... 28 2 2. Estimates of home range size (mean 1 SE) of the northern bobwhite quail at the Babcock Webb Wildlife Management Area, Florida (2002 2006) ................................ ... 29 2 3. Estimates of seasonal home range sizes of northern bobwhites at the Babcock Webb Wildlife Management Area, Florida (2002 2006) ................................ ............................. 30 2 4. Results of generalized linear models (GLM) investigating factors influencing the size of annual and seasonal home ranges of northern bobwhites in Babcock Webb Wildlife Management Area, Florida ................................ ................................ .................. 31 2 5. vector of 1s ................................ ................................ ................................ ......................... 31 2 6. Results of t tests following MANOVA analyses, results are presented as overall and stratified by gender and season ................................ ................................ .......................... 32 2 7. Results of t tests following MANOVA analyses stratified by year. ................................ .. 32 3 1. Description of habitat types represented and area occupied by each habitat type in Babcock Webb Wildlife Management Area, Florida ................................ ........................ 47 3 2. Results of t tests following MANOVA analyses testing for nest site selection. ............... 48 3 3. Results of logistic regression analysis testing for the influence of habitat composition and landscape structure on nest site selection. ................................ ................................ .. 48

PAGE 9

9 LIST OF FIGURES Figure page 2 1. Location of the Webb Babcock Wildlife Management Area in Charlotte County, south Flori da. Five management zones are indicated by bold, upper case letters ............. 33 2 2. Relationship between the density of random points per square kilometer and the variance of the average distance to habitat features ................................ ........................... 34 2 3. Size of bobwhite annual home ranges (ha; mean 1 SE) for each year of the study in Babcock Webb Wildlife Management Area, FL. A) Home ranges stratified by whether a home range contained a food plot and, B) stratified by gender. ....................... 35 3 1. Location of the Webb Babcock Wildlif e Management Area in Charlotte County, south Florida. Five management zones are indicated by bold, upper case letters. ............ 49 3 2. Number of nests found in various land cover types arranged in ascending order stratified by nest fate. Habitat type codes are: DP: D ry prairie, FP = F ood plot, OA = Odd area, PP = Pine palmetto, WP = W etland prairie. No nests were found in road, road grade or water. ................................ ................................ ................................ ........... 50 3 3. Comparison of habitat composition and landscape structure ar ound random points and nest locations (means 1 SE). A) Differences in linear feature density (road, road grade, and food plots, calculated within a 157 m window), B and C) Means of percentage land cover, D) means of standardized principal component scores for PCs 1, 2 and 3 ................................ ................................ ................................ ............................ 51 3 4. Comparison of habitat composition and landscape structure around successful and failed nests ( means 1 SE). A) Differences in linear feature density (road, road grade, and food plots, calculated within a 157 m window), B and C) Means of percentage land cover, D) means of standardized principal component scores for PCs 1, 2 and 3 ................................ ................................ ................................ ............................ 52

PAGE 10

10 Abstract o f Thesis Presented t o t he Graduate School o f t he University o f Florida in Partial Fulfillment o f t he Requirements f or t he Degree o f Master o f Science SPACE USE, HABITAT AND NEST SITE SELECTION BY NORTHERN BOBWHITES IN SOUTH FLORIDA By Aditya Singh Ma y 2009 Chair: Madan K. Oli Major: Wildlife Ecology and Conservation The manner by which animals use space and select resources can have important management consequences. Harvest records indicate that the northern bobwhite quail ( Colinus virginianus ) population in Babcock Webb Wildlife Management Area in Charlotte County, Florida, USA has been declining steadily since the 1970's. Th is decline ha s occurred despite the economic importance of the northern bobwhite as a game species and extensive efforts t o maintain and improve its population welfare. Using data from radio tagged bobwhites monitored from 2002 2007 at the Babcock Webb Wildlife Management Area, I examined factors influencing home range dynamics, habitat and nest site selection and the relati on of nest success with landscape composition and structure surrounding nest sites. The mean ( 1 SE) annual home range size, estimated using the Kernel density method, was 88.43 ( 6.16) ha, and did not differ between genders. Winter home ranges of bobwhi tes (69.27 4.92 ha) were generally larger than summer home ranges (53.90 4.93 ha). Annual and winter home ranges were smaller for bobwhites whose ranges contained food plots, compared to those that did not; however, the presence of food plots did not influence summer home ranges. Using a distance based method I investigate d habitat selection by bobwhites within home ranges. Bobwhites preferred food plots, pine palmetto and dry prairie habitats, and avoided wet

PAGE 11

11 prairies and roads grades. This pattern w as generally consistent between genders and across years. There was also strong evidence that bobwhites exhibited nesting habitat selection. Bobwhites preferred to establish nests closer to food plots ( P < 0.0001) and farther away from water bodies ( P = 0 .0003); other habitat types were neither preferred nor avoided. Habitat composition and landscape features differed between random points and nest sites, and landscape features that quantified connectedness and diversity significantly influenced the probab ility of nesting on a given site. Of a total of 365 nests monitored, only 208 (56.99%) were successful. Nesting success did not differ among habitat types, and none of the habitat and landscape variables we measured significantly influenced the probability of nesting success. These results suggest that random nest predation by meso mammalian predators, rather than habitat variables, may ultimately determine fates of bobwhite nests in south Florida. The results also provide further evidence for the importanc e of food plots.

PAGE 12

12 CHAPTER 1 INTRODUCTION Effective management of wildlife populations requires know ledge of how the species utilizes available landscape, and selects resources within it. Landscapes are inherently heterogeneous, and the choice of habitat as well as individual fitness (Fretwell and Lucas 1970, Holt 1985, Pulliam 1988) Quantifying behavioral responses to habitat heterogeneity may help identify essential resources and environmental conditions that affect population dynamics and may aid in the management of wildlife populations (Sutherland 1996, Boyce and McDonald 1999) Further more reproductive succ ess in many species of birds is influenced by nest site selection (Hatchwell et al. 1999) This is because placement and attributes of nest sites can affect risk of predation, access to food resources, and microclimate experienced by the developing embryos (Crabtree et al. 1989, Martin 1993, Lusk et al. 2006, Barea 2008) Populations of northern bobwhites have experienced substantial range wide declines in the past decades (Brennan 1991, Sauer et al. 2004, Williams et al. 2004, Brennan and Kuvlesky 2005) Harvest records indicate that the bobwhite population on Babcock Webb Wildlife Management Area (hereafter, WMA) in Charlotte County, Flori da, has been declining steadily (Dimmick et al. in press) Loss and degradation of habitat have been suggested to be an important cause of bobwhite population declines (Dimmick et al. 2002). Knowing how bobwhites utlilize space and select resources could, therefore, contribute to management efforts to reverse the population declines. However, data on space and habitat use patterns, a nd nesting ecology of bobwhites on Babcock Webb WMA remain relatively unknown.

PAGE 13

13 The overall goal of my thesis research is to provide information on space and habitat use by bobwhites and to investigate the nesting ecology of bobwhit es on the Babcock Webb WMA. In C hapter 2, I first present estimate s of the size of annual and seasonal home ranges, and investigate factors influencing home range sizes. Further, I test for habitat selection within home ranges by bobwhites, and examine variations in the pattern of habitat use over time and between genders. In C hapter 3, I test for the selection of nesting habitat by bobwhites and evaluate the influence of landscape and habitat characteristics on nest site selection I then examine the influence of habitat compos ition and structure on nesting success. Finally, in Chapter 4 I summarize main findings of the study, and provide recommendations for the management of bobwhites on the WMA based on my findings

PAGE 14

14 CHAPTER 2 PATTERNS OF SPACE AN D HABITAT USE BY NOR THERN B OBWHITES IN SOUTH FLORIDA Introduction Population declines of the northern bobwhite have been widely documented throughout southeastern United States (Brennan 1991, Sauer et al. 2004, Williams et al. 2004, Brennan and Kuvlesky 2005) These declines have occurred despite the economic importance of the northern bobwhite as a game species and extensive efforts to maintain and improve its population welfare. Hypotheses proposed to explain local or regional declines include reduction in fledgling survival due to predation by imported fire ants (Allen et al. 1995, Giuliano et al. 1996, Pedersen et al. 1996, Mueller et al. 1999) loss and fragmentation of habitat (FenskeCrawford and Niemi 1997, Fleming and Giuliano 2001) extreme weather events (Robel and Kemp 1997, Guthery et al. 2000, Lusk et al. 2001 Hernandez et al. 2005) and hunting pressure (Burger et al. 1999, Peterson 2001, Madison et al. 2002, Guthery et al. 2004a) An exhaustive review of the dramatic range wide populatio n declines of bobwhites in the southeastern range of the species conducted by the Southeastern Quail Study Group concluded that habitat losses including qualitative changes (conversion of native warm season grasses to exotic cool season and warm season spe cies), and quantitative habitat losses to urban expansion and transportation structures have been the most universally significant causes (Dimm ick et al. 2002) ecology, and thus have significant management implications (Webb and Guthery 1983, Guthery 1997, Guthery et al. 2004b, William s et al. 2004) Previous studies suggest that home range sizes of bobwhites vary regionally, and also are influenced by several intrinsic and extrinsic factors (e.g. Yoho and Dimmick 1972, Bell et al. 1985, Taylor et al. 1999, Terhune et al. 2006) Furthermore, resource selection and the proximate cues used by bobwhites in habitat

PAGE 15

15 selection may vary across spatial scales. Although bobwhites occupy a wide variety of habitats across their range in the United States (Roseberry et al. 1994, Taylor and Guthery 1994, Barnes et al. 1995, Dixon et al. 1996) they may demonstrate an affinity for specific habitat types on a local scale. Furthermore, energetic demands for thermoregulation and nutritional requirements of bobw hites may vary among seasons (Townsend et al. 1999) A variety of foods is required to meet the special requirements o f growing chicks, breeding hens, and all sex age classes during fall and winter (Dimmick 1992) Cover that affords protection from weather, predators, and hunters is paramount in fall, winter, and early spring. Good nesting cover consists of vegetation suitable for building the nest and concealing it and the clutch of egg s. The degree of interspersion of the components of food and cover is a major determinant of the quality of the specific patterns of space use and habitat selection is necessary for evaluating the suitability of different land cover types, and for managing habitat to enhance bobwhite survival and reproduction. However, prior to the initiation of this study, data on space and habitat use by bobwhites in south Florida were scarce. Harvest records indicate that the bobwhite population in Babcock Webb Wildlife Management Area in Charlotte County, Florida, USA (hereafter, Babcock Webb WMA) has (Dimmick et al. in press) The numbers of bobwhites in the area remain low despite a significant effort to reverse this trend. Management of bobwhites in south Florida could benefit from an understanding of the patterns of space and habita t use in this ecoregion. However, information on home range sizes and habitat preferences of bobwhites in south Florida is currently incomplete. Our goal was to fill this gap in knowledge and provide information on space and habitat use by bobwhites on the Babcock Webb WMA. Specifically, we estimated the size of annual and seasonal home ranges, and investigated factors influencing

PAGE 16

16 home range sizes. Secondly, we tested for habitat selection within home ranges by bobwhites, and examined variations in the patt ern of habitat use over time and between genders. Study Area a nd Methods Study A rea The study was conducted on the Babcock Webb WMA in Charlotte County, FL. The WMA is located in south Florida, its western border about 8 km east of the town of Punta Gorda (Fig. 2 1). The WMA comprises 26,818 ha, encompassing 3 major and 5 minor habitat types (Table 2 1). The most significant plant communities included dry prairie (9,737 ha), pine palmetto (9,145 ha) and wet prairie (7,047 ha). Vegetation on our study site was described in detail by Frye (1954) Sesbania sp food plots, planted in 3m wide strips, comprise 0.56% (151 ha) of the area of the WMA. Topography is flat, and the soil is sandy. The surface floods p eriodically following heavy rains, but drains rapidly when rainfall ceases. The area is subject to prolonged drought, sometimes lasting several years. Water depths of several centimeters may cover more than 50% of the surface for several days. Both of t hese weather extremes likely affect bobwhite habitat selection, survival, and reproduction. Currently, controlled burning and roller chopping are the primary habitat management activities conducted on the WMA. During the last 2 decades, several kilometers of Sesbania sp. strips were planted in concentrated areas throughout the area. These strips are rejuvenated and fertilized as needed on an annual basis. Some regulated grazing occurs in various places on the area under lease agreements with local rancher s. Efforts to reduce or eliminate noxious non native plants are ongoing, and have been successful.

PAGE 17

17 Trapping and R adio T elemetry We captured bobwhites during all months of the year from October 2002 through March 2007, except in areas where the bobwhite hu nting season was in progress. We used baited funnel traps during the non breeding season. We used the same traps to capture birds during the breeding season; however, we placed a female in a small enclosure in the main trap to entice males (call back tra pping). The call back trapping was enhanced by playing recordings of females using tape players capable of playing a continuous loop of calls. Cast nets approximately 3 m in diameter were used to capture birds throughout the year. The cast nets were modif ied by removing the drawstrings and doubling the number of weights on the lead line. During daylight hours birds were located with radios and cast nets were used to capture unmarked birds that were associated with them. We used birddogs to locate bobwhite s when radio marked birds were not in an area where we wished to capture birds. At night we located radio marked birds on their roost and captured them and their associated covey mates with the cast net. All trapping and handling protocols were approved by the University of Florida Institutional Animal Care and Use Committee (protocol number A 794). We located radio marked birds using hand held receivers and Yagi antennas. We searched for individual birds at 3 5 day intervals, traversing the area with 4 wh eel drive all terrain vehicles and trucks. Truck mounted whip antennas were used to locate birds that went missing for several days. This was effective for relocating birds that had traversed long distances from their established home ranges, or from the capture site. The location of each radio marked bird was established using the homing procedure and logged into a GPS unit for later transfer to an office based computer. All data were stored in a database management system with the individual entries co ntrolled by a 5 digit leg band number. Birds were weighed to the nearest gram, aged, sexed, and leg banded. Birds weighing at least 130 g were fitted with a necklace

PAGE 18

18 style transmitter with a mortality sensor weighing 6 g. Antenna length was 22 cm. Transmi tters had an expected battery life of 365 days, and a signal range of about 500 to 1000 m in the WMA habitat. L eft align text throughout (ragged right) While many of you prefer the look of justified text research has shown that ragged right text is easier to read than justified text. Both the irregular shape of the text on the right that gives the eye a reference point and the regular word and character spacing of unjustified text make life easier on the reader. Data A nalysis Home R ange S izes : We monitored 1245 radio tagged bobwhites for 19,467 radio days from October 2002 to March 2007. These data were used to investigate factors influencing annual and seasonal home range sizes and habitat selection. To analyze annual home ranges, we used radio locations collected from October 1 of year 1 to September 30 of year 2. The annual period thus spanned both winter (1 st October 31 st March) and summer (1 st April 30 th September) seasons. Annual home ranges were estimated nning at least 3 months in each season. We did not include data for 2006 07 for these analyses because they included radiolocations from the winter season only. We estimated annual home ranges using the 95% Kernel density method (Worto n 1989, Seaman and Powell 1996) using the least cost cross validation procedure in ArcView Animal Movement Analyst (Hooge and Eichenlaub 2000) For comparison purposes, we also calculated 95% minimum convex polygon h ome ranges (White and Garrott 1990) To analyze estimated home ranges as described previously. We log transformed estimates of home range size prior to analyses, and analyzed annual and seasonal home ranges sepa rately. We first tested separately for the effect on annual home range size of gender, year of study (2002 03, 2003 04, 2004 05, 2005 06), and a variable

PAGE 19

19 describing whether a home range intersected a food plot using 2 sample t tests or ANOVAs, as appropria te. For these analyses, we considered the effect of one variable at a time. Next, we fitted a series of general linear models (GLMs), and tested for all main and 2 way interaction effects of the aforementioned variables (Slade et al. 1997, Moyer et al. 2007) We sequentially removed non wise fashion such that the least significant interaction term was removed each time. The models were refitted sequentially until all main effects and only significant interac tion effects remained in the model (Slade et al. 1997, Moyer et al. 2007) We further explored the significant interaction effects in the final models using the least squares means (lsmeans) multiple comparison procedures. Seasonal home ranges were analyzed similarly except that season (summer or winter) was included as an effect, and we also included data collected during winter of 2006 07. Habitat Selection : We used a distance based method (Conner et al. 2003) to investigate habitat selection, and to exami ne if the pattern of habitat selection differed between genders and seasons, and varied across years. We preferred this method because two of our habitat types (food plots, and road grades) were essentially linear features; this precluded the use of method s that require area based estimates of habitat availability (e.g. compositional analysis, Aebischer et al. 1993) The distance based approach compares observed distances from radio locations to a given habitat type with the expected distance to that habitat type in order to test the hypothesis that habitat types are used in proportion to their availabilities (Conner et al. 2003, Perkins and Conner 2004, Conner et al. 2005) When compared to classification based methods, inferences based on the distance ba sed analysis are more robust with respect to habitat misclassifications (Bingham and Brennan 2004)

PAGE 20

20 Random points were generated inside the home range of each bird with a uniform distribution at the density of 200 points per km 2 using custom scripts written in ArcView. This density of points was selected because it was where the variance of the average distance to a given habitat type began to stabilize (Figure 2 2). These point s defined habitat availability The distance from each random point was measured in each home range t o the nearest patch of each habitat type. We created vectors of distances of these random points to each habitat type ( r ). Entries in r represented expected values of distances under the null hypothesis of no habitat selection (Conner et al. 2003) We also created a vector u; entries in u represented distances f rom radiolocations to each habitat type. Entries in u represented habitat use. A vector of ratios ( d ) was created by dividing each entry in u by the corresponding entry in r Entries equaling 1.0 in d indicated that habitat use equaled habitat availability for a given habitat type. These ratios were averaged over all individual quail to produce a vector The null hypothesis that variance (MANOVA). Rejection of the null hypothesis of no habitat selection indicated that use differed from availability for at lea st one habitat type. If the null hypothesis was rejected, we used a paired t test to compare each entry in to 1.0 to determine which habitat types were used differently than expected (Conner et al. 2003) When an entry in was < 1, radiolocations were closer than expected (indicating preference), and when an entry in was > 1, radiolocations were farther away than expected (indicating avoidance). The entries in were then used to rank the habitat types in order of preference. Significant differences among habitat types were determined using a paired t test (Conner et al. 2003) We tested for habitat selection using all data to examine the pattern of overall habitat selection. We then repeated the analyses by year, gender,

PAGE 21

21 and season to test for annual, gender specific and seasonal patterns of habitat selection, respectively. Arabic numerals (1, 2, 3, etc.) centered at the bottom of each page Every page is counted and numbered. The major issue with page numbers is when you have to use a broadside (or Landscape) orient ation. In this case the page is rotated 90 degrees clockwise and the page number is placed in the same relative position it would be on a portrait page. One half inch from the left edge, centered vertically and rotated 90 degrees clockwise. Results Annual H ome R anges Data were adequate for estimating annual home ranges for 174 birds. The mean ( 1 SE) size of annual home ranges varied from 82.25 9.84 ha in 2005 2006 to 97.30 23.29 ha in 2002 2003, with an overall mean of 88.43 6.16 ha (Table 2 2). A nnual home ranges estimated by the minimum convex polygon method ranged from 50.81 8.77 ha in 2003 04 to 68.74 18.09 ha in 2002 03, and were generally smaller than those obtained from the Kernel density method (Table 2 2). When the effect of each fact or was tested separately, we found that annual home ranges did not differ significantly between genders ( t = 1.12, P = 0.266), nor did they vary across years of study ( F = 1.34, P = 0.2630). However, home ranges of bobwhites that contained food plots (80.5 0 6.24 ha) were significantly smaller ( t = 3.27, P = 0.0013) than those that did not contain food plots (133.57 19.02 ha; Table 2 2) When the effect of year, gender, and the presence of food plots was evaluated simultaneously, we found that the mai n effect of year ( F = 4.46, P = 0.0049) and gender ( F = 8.03, P = 0.0052) was significant. Moreover, the interaction effect of year and the presence of food plots was significant ( F = 5.06, P = 0.0074; Table 2 4), indicating that the influence of food plot s on home range size varied across years. Least square mean comparison procedures

PAGE 22

22 revealed that, in 2004 05 home ranges that did not contain food plots were significantly larger (146.6621.94) than those that did (73.176.14; P = 0.0022); the small number of home ranges without food plots in other years precluded similar comparisons ( N = 0, 2, and 3 in 2002 2003, 2003 2004, and 2005 2006, respectively). The interaction effect of gender and year also was significant ( P = 0.0022; Table 2 4); however, neither males nor females had consistently larger (or smaller) home ranges during all years of study (Fig. 2 3B). Seasonal H ome R anges The mean size of summer home range was 53.90 4.93 ha and that of winter home range was 69.27 4.92 ha (Table 2 3). Summer an d winter home ranges estimated by the minimum convex polygon method were 27.96 1.84 ha and 37.28 2.67 ha, respectively and were generally smaller than those obtained from the kernel density method (Table 2 3). Tests of single factor effects revealed t hat winter home range size did not differ between bobwhites whose home range did or did not contain food plots ( t = 1.64, P = 0.103). However, winter home ranges varied significantly across years ( F = 2.45, P = 0.0483) with larger home ranges during 2002 0 3 than in 2006 07 (Table 2 3); there were no other statistically significant differences. When the effect of all factors was evaluated simultaneously, the main effect of the presence of food plots was significant ( F = 7.16, P = 0.0082); winter home ranges that contained food plots were significantly smaller than those that did not (Table 2 3). The main effect of year was also significant ( F = 3.26, P = 0.0133), with larger winter home ranges in 2002 03 than in 2006 07 ( P = 0.0390). None of the interaction effects was significant (Table 2 4). Single factor analysis revealed that summer home ranges differed significantly between genders ( t = 2.36, P = 0.021), with males (55.33 3.82 ha) maintaining larger summer home ranges than females (51.51 11.6282 ha; Table 2 3). Annual differences in summer home range size also were significant ( F = 2.73, P = 0.0469), with smaller summer home ranges during

PAGE 23

23 2003 04 than most other years (Table 2 3). The effect of food plots on summer home range size was not significan t. When the effect of all factors was tested simultaneously, the only significant main effect was that of gender ( F = 5.88, P = 0.0168) wherein males had larger home ranges than females (Table 2 3). None of the interaction effects was significant. Habita t S election Distance ratios analyzed using the MANOVA procedure revealed that bobwhite radiolocations differed significantly from random locations overall ( F = 166.6, P < 0.0001), and when considered separately for each gender ( F = 150.12, P < 0.0001), sea son, ( F = 209.56, P < 0.0001), and year ( F = 198.75, P < 0.0001; Table 2 5). Thus, bobwhites exhibited strong habitat selection, indicating that some habitats were used more or less than expected by chance alone. Food plots were strongly preferred by both males and females, in both seasons and across all years of study (Tables 2 6, 2 7). Pine palmetto habitat was preferred by male bobwhites, but not by females (Table 2 6). Pooled across genders, pine palmetto habitat was preferred by bobwhites across both seasons (Table 2 6), and in all years except 2002 03 and 2004 05 (Table 2 7). Dry prairie habitat was generally preferred by bobwhites but the pattern of selection was not consistent across genders, seasons or years. Females preferred dry prairie habitat b ut males did not (Table 2 6). When data were pooled across genders, bobwhites strongly preferred dry prairie habitat in winter, but not in summer (Table 2 6). Across years, dry prairie habitat was preferred in 2002 03 and 2004 05 and avoided in 2003 04. Dr y prairie was used randomly in 2005 06 (Table 2 7). Bobwhites generally avoided wet prairie habitat but the pattern of selection varied. Male bobwhites were found farther than expected from wet prairie habitats; however, females used wet prairies randomly (Table 2 6). Across seasons, wet prairie habitats were preferred in winters but avoided in summers. Across years, bobwhites generally avoided wet prairie habitats except

PAGE 24

24 in the year 2004 05(Tables 2 6 and 2 7). Bobwhites were generally found farther than expected from water bodies, road grades and odd areas; the pattern was consistent across genders and seasons (Table 2 6). Water bodies and road grades were avoided throughout the study period except in 2004 05 when they were preferred (Table 2 7). Similarl y, odd areas were preferred only in year 2002 03 (Table 2 7). Discussion Effective management of game species requires knowing how the species utilizes available landscape, and selects resources within it. Landscapes are inherently heterogeneous, and the c fitness (Fretwell and Lucas 1970, Holt 1985, Pulliam 1988) Quantifying behavioral responses to habitat heterogeneity m ay help identify essential resources and environmental conditions that affect population dynamics and may aid in the management of wildlife populations (Sutherland 1996, Boyce and McDonald 1999) During the period of this study the bobwhite population on the majority of the Babcock Webb WMA existed at a very low density in contrast with many other managed habitats across (Dimmick et al. in press) The population reached this very low density follo exceeded 5000 birds per year (Florida Fish and Wildlife Conservation Commission, unpublished data).The population decline almost surely reflected deterioration in the quality of the habitat, and this deterioration may have been facilitated by various changes in management practices as well as other activities occurring on the area or its perimeter. It is also possible that the population has been over harvested, partic ularly during recent years when legal harvest removed birds at a rate believed to be unsustainable (Dimmick et al. in press) Efforts to reverse th e downward spiral in the bobwhite population are currently underway; our goal was to assist the

PAGE 25

25 Florida Fish and Wildlife Conservation Commission in this effort by providing data on space and habitat use by bobwhites on the WMA. Characteristically, bobwhi (Wiseman and Lewis 1981, Sisson et al. 2000) (Bell et al. 1985, Dixon et al. 1996, Guthery et al. 2004b, Haines et al. 2004, Terhune et al. 2006) The mean annual home range size in our study area was 88.43 6.16 ha, which is sub stantially larger than most previously reported bobwhite home ranges. Resource availability and habitat productivity have been shown to have tremendous influences on home range sizes in many wildlife species (Samson and Huot 1998, Koehler and Pierce 2003, Moyer et al. 2007) and extremely large bobwhite home ranges observed in our study most l ikely reflects that some component of the habitat is poor on the WMA. Several intrinsic and extrinsic environmental factors, alone or in concert, can influence annual or seasonal home range sizes (e.g. Badyaev et al. 1996, Slade et al. 1997, Moyer et al. 2007, Whi taker et al. 2007) For example, stochastic variation in the environment can influence home range size but the pattern of influence can vary depending on other factors, such as gender and resource availability. We found that there was a significant inter action between gender and year, but the difference in home range size between genders was not consistent across years (Fig. 2 3). Likewise, there was no gender difference in winter home ranges as would be expected because they are in coveys. However, males maintained larger summer home ranges than females. Taylor et al. (1999) found that male bobwhites had significantly larger home ranges than females in one study site, but the pattern was reversed in another study site. Thus, bobwhites apparently do not follow systematic gender differ ences in home range size observed in many species of birds and mammals (Oka 1992, Begg et al. 2005, Favaron et al. 2006)

PAGE 26

26 We believe that the generally larger ho me ranges during winter than in summer observed in our study are primarily a consequence of food resource limitation, particularly limited availability of slough grass ( Spartina pectinata ; an important food source for bobwhites in our study area). Animals tend to roam more widely during seasons of lower resource abundance in search of scarce and patchily distributed resources, which would lead to larger home ranges (e.g. Yo et al. 1992, Chapman et al. 1993, Ndithia and Perrin 2006) Another possibility is that larger home ranges during winter ma y also be due to hunting induced disturbances, as is commonly observed in other game birds (Whitaker et al. 2007) Bobwhites showed a strong response to food plots in our study area. Annual home ranges were generally smaller for birds whose ranges contained food plots compared to those that did not; Sisson et al. (2000) and W.E. Palmer (Tall Timbers Research Station, pers. comm. 2009) both observed a similar response to supplemental feeding. The fact that there were few home ranges that did not intersect food plots is itself an indication that food plots markedly influenced the habitat chosen by bobwhites on the WMA in years other than 2004 05. The same pattern was observed for winter home ranges as well. Although summer home ranges that contained food plots were larger than home ranges that did not, the effect was not significant. Food plots and supplemental feeding are widely used practices for managing bobwhite populations in North America (Townsend et al. 1999, Guthery et al. 2004b, Haines et al. 2004) In our study area, the provision of food p lots seemed to stabilise resource availability for bobwhites, thereby contributing to reduction in home range size. This suggestion is further supported by the fact that food plots significantly contributed to reduction in size of winter, but not summer, h ome ranges. Our results, along with those of Guthery et al. (2004b) suggest that bobwhite home ranges are strongly influenced by food availability such that bobwhites inhabiting poor quality habitat

PAGE 27

27 (or within a site, during seasons of lower food availability) typically need larger home ranges to satisfy their resource needs (Sisson et al. 2000 and W.E. Palmer, Tall Timbers Research Station, pers. comm. 2009) The effects of supplemental food on home range size may vary, depending perhaps on local habitat conditions (e.g., Haines et al. 2004) Bobwhites were generally found closer to food plots as compared to other habitat types, indicating a preference for this habitat type. This may have resulted from the concentration of coveys around supplemental food sources (Guthery et al. 2004b, Haines et al. 2004) Other habitat types preferred by bobwhites included pine palmetto and dry prairie, and these patterns were consistent between sexes and seasons.

PAGE 28

28 Table 2 1 De scription of habitat types represented and area occupied by each habitat type in Babcock Webb Wildlife Management Area, Florida. Habitat a Description Area (ha) %Area Dry Prairie (DP) Herbaceous and low shrub communities on seldom flooded, sandy soil are as very similar to pine palmetto, differing from them mainly by their lack of pines and sparse palmetto. Utilized by quail throughout the year for nesting, brood rearing, and roosting. 9736.96 36.308 Pine Palmetto (PP) Open stands of slash pine ( Pinus c aribaea ) on poorly drained soils, with an understory of saw palmetto ( Serenoa repens ), wire grass ( Aristida stricta ), broomsedge ( Andropogon spp .) and other grasses. Various panic grasses ( Panicum spp .), slough grass ( Scleria setacea ), and dwarf wax myrtl e ( Cerothanmus pumilus ) are used by quail for feeding and/or nesting. 9145.19 34.101 Wet prairie (WP) Herbaceous communities on low seasonally flooded transitional areas between permanent wetlands and drier communities. Important to quail primarily becaus e of the abundant slough grass. Use is limited when they are flooded but commonly utilized when wet but not flooded. 7046.93 26.277 Odd Area (OA) Buildings and other human use areas not generally considered quail habitat. 508.09 1.895 Water (WA) Permane nt ponds, natural and man made, surrounded by emergent aquatic plants. 192.35 0.717 Food Plot (FP) Continuous serpentine stands of Sesbania sp ., an erect legume approximating 2 3 m in height. Width of the food plots is about 7 m. Ground cover beneath the plants is generally open and sandy. 151.21 0.564 Road Grade (RG) Roads prepared by grading to create a surface approximately 1+ m above the surrounding habitat. 18.75 0.07 Road (RD) Field roads not elevated above the surrounding surface 18.42 0.069 TOTAL 26817.9 0 100 .000 a Description of habitat types adopted from Frye (1954), with modifications.

PAGE 29

29 Table 2 2 Estimates of home range size (mean 1 SE) of the northern bobwhite quail at the Babcock Webb Wildlife Management Area, Florida ( 2002 20 06 ) Me an home range size (ha) n No. of locations 95% Kernel density estimates (range ha.) 95% MCP estimates A. By year 2002 03 10 38.60 1.77 97.30 23.29 (5.69 235.64) 68.74 18.09 2003 04 44 38.86 1.01 84.30 16.33 (10.69 544.30) 50.81 8.77 2004 05 78 37.24 0.74 92.96 8.36 (9.07 475.83) 62.33 5.00 2005 06 42 37.95 0.96 82.25 9.84 (14.02 331.47) 56.91 5.65 B. By gender Female 75 38.89 0.83 84.06 8.58 (5.69 362.93) 59.00 5.88 Male 99 37.15 0.58 91. 74 8.69 (9.07 544.30) 58.08 4.47 C. Home range intersected a food plot Yes 148 38.32 0.54 80.50 6.24 (5.69 544.30) 52.16 3.81 No 26 35.50 1.10 133.57 19.02 (10.69 475.83) 82.67 8.16 Overall 174 37.90 0.49 88.43 6.16 ( 5.69 544.30) 58.48 3.58

PAGE 30

30 Table 2 3 Estimates of seasonal home range sizes of northern bobwhites at the Babcock Webb Wildlife Management Area, Florida ( 2002 2006 ) Mean home range size (ha) n No. of locations 95% Kernel density estimates (range ha.) 95% MCP estimates A. Overall Summer 123 23.81 0.31 53.90 4.93 (5.2 8 530.06) 27.96 1.84 Winter 167 26.03 0.27 69.27 4.92 (5.59 401.57) 37.28 2.67 Overall 290 25.10 0.22 62.75 3.55 (5.28 530.06) 33.03 1.74 B. Winter Gender Female 72 26.14 0.37 62.25 7.30 (5.59 278.71) 34.74 4.21 Male 95 25.95 0.39 74.59 6.63 (5.59 401.58) 39.21 3.46 Intersected a food plot? Yes 124 25.73 0.33 66.84 5.83 (5.59 401.58) 34.31 2.94 No 43 26.88 0.44 76.29 9.11 (9.25 223.33) 42.06 5.09 Year 2002 03 5 23.40 1.54 160.28 66.20 (33.64 401.58) 83.16 34.47 2003 04 36 26.44 0.80 79.35 11.31 (10.40 278.71) 40.14 5.68 2004 05 75 26.41 0.35 69.15 6.97 (5.59 236.86) 38.74 4.09 2005 06 13 24.23 0.63 58.79 9.95 (29.21 141.94) 29.14 5.25 2006 07 38 25.84 0.52 51.57 7.50 (6.60 188.29) 34.74 4.21 C. Summer Gender Female 46 24.17 0.60 51.51 11.62 (5.28 530.06) 26.36 3.82 Male 77 23.60 0.35 55.33 3.82 (9.59 148.38) 28.92 1.86 Intersected a foo d plot? Yes 113 21.80 0.71 54.60 5.26 (5.28 530.06) 28.36 1.96 No 10 23.99 0.33 46.06 12.95 (7.23 148.38) 24.91 5.31 Year 2002 03 14 27.21 1.56 58.54 10.13 (5.28 114.99) 35.01 5.96 2003 04 23 21.70 0.30 35.31 5.95 (7.2 3 113.48) 18.84 2.95 2004 05 40 24.00 0.33 64.07 12.81 (10.10 530.06) 30.79 4.03 2005 06 46 23.67 0.50 52.95 5.41 (9.68 148.38) 27.93 2.36

PAGE 31

31 Table 2 4 Results of generalized linear models (GLM) investigating factors influencing the s ize of annual and seasonal home ranges of northern bobwhites in Babcock Webb Wildlife Management Area, Florida Source df Mean Square F P Annual Gender 1 4.485 8.03 0.0052 Year 3 2.492 4.46 0.0049 FP # 1 0.220 0.39 0.5311 FP*Year 2 2.824 5.06 0.0074 Gender*Year 3 2.827 5.06 0.0022 Seasonal Winter Gender 1 1.352 1.89 0.1710 Year 4 2.333 3.26 0.0133 FP 1 5.120 7.16 0.0082 Summer Gender 1 3.371 5.88 0.0168 Year 3 1.513 2.64 0.0527 FP 1 0.132 0.23 0.6318 FP # : Factor describing whether home range intersects food plot Table 2 5 Results of MANOVA vector of 1s F df P Overall 166.6 0 8 <.0001 Gender 150.12 8 <.0001 Season 209.56 8 <.0001 Year 198.75 8 <.0001

PAGE 32

32 Table 2 6 Results of t tests following MANOVA analyses r esults are presented as over all and stratified by gender and season By Gender By Season Overall Female Male Summer Winter Habitat a t P Rank t P Rank t P Rank t P Rank t P Rank DP 2.35 0.019 4 2.26 0.0241 3 1.18 0.2381 3 0.56 0.5773 4 3.65 0.0003 4 FP 33.53 <.0001 1 12.77 <.0001 1 37.62 <.0001 1 58.06 <.0001 1 12.03 <.0001 1 OA 21.56 <.0001 8 14.24 <.0001 8 16.2 <.0001 8 20.18 <.0001 8 11.86 <.0001 8 PP 7.12 <.0001 2 1. 57 0.1174 5 8.33 <.0001 2 8.42 <.0001 2 2.72 0.0066 7 RD 3.95 <.0001 3 9.29 <.0001 2 2.03 0.0423 4 2.73 0.0064 3 2.86 0.0043 6 RG 9.22 <.0001 7 1.82 0.069 4 12.11 <.0001 7 17.17 <.0001 6 3.71 0.0002 3 WA 7.49 <.0001 6 2.03 0.0423 7 7.99 <.0001 6 19.43 <.0001 7 5.22 <.0001 2 WP 3.36 0.0008 5 0.29 0.7708 6 4.54 <.0001 5 8.3 <.0001 5 3.33 0.0009 5 a D P = Dry Prairie, FP = Food Plot, OA = Odd Area, PP = Pine Palmetto, RD = Road, R G = Road Grade, WA = Water, WP = W et prairie T able 2 7 Results of t tests following MANOVA analyses stratified by year. 2002 03 2003 04 2004 05 2005 06 Habitat a t P Rank t P Rank t P Rank t P Rank DP 6.71 <.0001 3 4.86 <.0001 3 5.1 <.0001 6 0.35 0.7289 4 FP 32.04 <.0001 1 180.51 <.0001 1 8.28 <.0001 3 26.37 <.0001 1 OA 20.93 <.0001 2 14.98 <.0001 7 11.51 <.0001 8 15.26 <.0001 8 PP 0.2 0.8391 4 15.57 <.0001 2 0.75 0.4542 7 4.27 <.0001 3 RD 16.64 <.0001 6 13.02 <.0001 6 18.5 <.0001 1 7.63 <.0001 2 RG 21.37 <.0001 8 18.95 <.0001 8 7.74 <.0001 4 4.02 <.0001 7 WA 17.39 <.0001 7 12.44 <.0001 5 9.72 <.0001 2 2.92 0.0036 6 WP 11.85 <.0001 5 8 <.0001 4 6.66 <. 0001 5 2.47 0.0138 5 a D P = Dry Prairie, FP = Food Plot, OA = Odd Area, PP = Pine Palmetto, RD = Road, R G = Road Grade, WA = Water, WP = W et prairie

PAGE 33

33 Figure 2 1 Location of the Webb Babcock Wildlife Management Area in Charlotte County, south Florida Five management zones are indicated by bold, upper case letters

PAGE 34

34 Figure 2 2 Relationship between the density of random points per square kilometer and the variance of the average distance to habitat features

PAGE 35

35 Figure 2 3 Size of bobwhite annual home ranges (ha; mean 1 SE) for each year of the study in Babcock Webb Wildlife Management Area, FL A) Home ranges stratified by whether a home range contained a food plot and B) stratified by gender.

PAGE 36

36 CHAPTER 3 THE INFLUENCE OF NES T SITE SELECTION ON BO BWHITE NESTING SUCCE SS IN SOUTH FLORIDA Introduction Reproductive success in many species of birds is heavily influenced by nest site selection (Hatchwell et al. 1999) This is because placement and attributes of nest sites can affect risk of predation, access to food resources, and microclimate exper ienced by the developing embryos (Crabtree et al. 1989, Martin 1993, Lusk et al. 2006, Barea 2008) Nest sites that offer protection from predators and weather elements is especially crucial for the reproductive su ccess of ground nesting birds such as northern bobwhites ( Colinus virginianus ), because predation or abandonment of ground nests can lead to a complete reproductive failure. Thus, nest site selection can have important population dynamic consequences, par ticularly in species characterized by early maturity and large clutch size. This is because population growth rates in such species are highly sensitive to reproductive parameters (Heppell et al. 2000, Saether and Ba kke 2000, Stahl and Oli 2006) Populations of northern bobwhites have experienced substantial range wide declines (Brennan 1991, Sauer et al. 2004, Williams et al. 2004, Brennan and Kuvlesky 2005) Consistent with the range wide trend, harvest records indicate that the bobwhite population in Babcock Webb Wildlife Management Area in Charlotte County, Florida, USA (hereafter, Babcock (Dimmick et al. in press) Management of this population could benefit from knowledge of nesting ecology of bobwhites on the WMA, but information on nest site selection and factors influencing nest site selection and nesting success are currently not available.

PAGE 37

37 Our goal was to investigate nesting ecology of bobwhites on the WMA. Specifically, our objectives were to: 1) test for the selection of nesting habitat by bobwhites; 2) evaluate the influence of landscape and habitat characteristics on nest site selection and 3) investigate factors influencing nesting success. Study A rea The study was conducted on the Babcock Webb WMA in Charlotte County, FL. The WMA is located in south Florida, its western border about 8 km east of the town of Punta Gorda (Fig. 3 1). Th e WMA comprises 26,818 ha, encompassing 3 major and 5 minor habitat types (Table 3 1). The most significant plant communities included dry prairie (9,737 ha), pine palmetto (9,145 ha) and wet prairie (7,047 ha). Vegetation on our study site was described in detail by Frye (1954) Sesbania sp food plots, planted in 3m wide strips, comprise 0.56% (151 ha) of the area of the WMA. Topography is flat, and the soil is sandy. The surface floods periodically fol lowing heavy rains, but drains rapidly when rainfall ceases. The area is subject to prolonged drought, sometimes lasting several years. Water depths of several centimeters may cover more than 50% of the surface for several days. Both of these weather ex tremes likely affect bobwhite habitat selection, survival, and reproduction. Currently, controlled burning and roller chopping are the primary habitat management activities conducted on the WMA. During the last 2 decades, several kilometers of Sesbania sp strips were planted in concentrated areas throughout the area. These strips are rejuvenated and fertilized as needed on an annual basis. Some regulated grazing occurs in various places on the area under lease agreements with local ranchers. Efforts to reduce or eliminate noxious non native plants are ongoing, and have been successful.

PAGE 38

38 Methods Trapping and R adio T elemetry We captured bobwhites during all months of the year from October 2002 through March 2007, except in areas where the bobwhite hunting s eason was in progress. We used baited funnel traps during the non breeding season. The same traps were used to capture birds during the breeding season; however we used call back trapping using caged female quail to entice males. We used cast nets appro ximately 3 m in diameter to capture birds throughout the year. During daylight hours we located birds with radios and cast the nets to capture unmarked birds that were associated with them. At night we located radio marked birds on their roost and capture d them and their associated covey mates with the cast net. Radio marked birds were located using hand held receivers and Yagi antennas. Individual birds were searched for at 3 5 day intervals by traversing the area with 4 wheel drive all terrain vehicles and trucks. We used a truck mounted whip antenna to locate birds that went missing for several days. This was effective for relocating birds that had traversed long distances from their established home ranges, or from the capture site. Other details of the trapping protocol are described in detail elsewhere (Singh et al. in prep ). All trapping and handling protocols were approved by the University of Florida Institutional Animal Care and Use Committee. Nest L ocations and N esting S uccess All nests monito red during the study were located by tracking radio tagged birds. We located nests from the middle of March through the middle of October. If a bobwhite was located in the same area >2 days during the nesting season, the area was thoroughly searched for p ossible nests. On locating a nest, we noted habitat characteristics (e.g., habitat type, burn history), and recorded GPS coordinates. We took two photographs, one up close and one covering the wider view of the surrounding habitat. We attempted to check e ach nest at least

PAGE 39

39 every third day from the time it was located until its fate. We categorized the fate of nests into three discrete categories, hatched (successful), destroyed or abandoned. We determine a cut off out of the bottom of an egg (by the chick). However, nests occasionally get disturbed by other animals after the eggs hatch. On encountering a nest that seemed destroyed, we termed it as a hatched nest if at least one of such caps were found on t he nest location. Destroyed nests either have no eggs left in them or there is adults would leave a nest during egg laying or incubation and would never com e back. Such nests were termed abandoned. Locations of all nest sites were entered in a geographical information system (GIS) compatible database and projected to a common projection system and datum (Albers, GRS 1980). Throughout, we followed Florida G eographic Data Library (FGDL) GIS metadata standards. We subsequently analyzed data in two complementary ways: to test for the selection of nest sites and to identify landscape level attributes associated with the fate of the nests. Testing for N est S ite S election We used the distance based method of Conner et al (2003) to test for the nest site selection. The distance based method has received wide application in a number of contexts (Parra 2006, Xu et al. 2007, Elfstrom et al. 2008, Riedle et al. 2008) We preferred this method because three of our habitat types (food plots, road, and road grade) were essentially linear features; this precluded the use of methods that require area based estimates of habitat availability (e.g. compositional analysis, Aebischer et al. 1993) The distance based approach compares observed distances from nest locations to a given habitat type with the expected distance to that habitat type in order to test the hypothesis that habitat types are used for nesting in proportion to their avai labilities (Conner et al. 2003, Perkins and Conner 2004, Conner et al.

PAGE 40

40 2005) When compared to classification based methods, inferences based on the distance based analysis are more robust with respect to habitat misclassifications (Bingham and Brennan 2004) polygon (Worton 1989) encompassing all nest locations. The 95% Kernel density polygon was estimated using the least squares cross validation procedure in ArcV iew Animal Movement Analyst (Hooge and Eichenlaub 2000) We generated random points across the 95% Kernel density polygon at a density of ~5 points per hectare. These random points therefore defined We measured the distance from each random point to the nearest patch of each hab itat. We created vectors of distances of these random points to each habitat type ( r ). Entries in r represented expected values of distances under the null hypothesis of no habitat selection (Conner et al. 2003) We also created a vector u; entries in u represented distances from nest sites to each habitat type. Entries in u represented habitat use. A vector of ratios ( d ) was created by dividing each entry in u by the corresponding entry in r Entries equaling 1.0 in d indicated that habitat use equaled habitat availability for a given habitat type. These ratios were averaged over all nest sites to produce a vector The null hypothesis that is not significantly different the null hypothesis of no nest site selection indicated that use differed from availability for at l east one habitat type. If the null hypothesis was rejected, we used a paired t test to compare each entry in to 1.0 to determine which habitat types were used differently than expected (Conner et al. 2003) When an entry in was < 1, nests were closer than expected (indicating preference), and when an entry i n was > 1, nests were farther away than expected (indicating avoidance). The entries in were then used to rank the habitat types in order of preference. Significant

PAGE 41

41 differences among habitat types were determined using a paired t test (Conner et al. 20 03). We first tested for nest site selection using all data to examine the pattern of overall selection. We then repeated the analyses with data stratified by nest fate to test for differences between successful, abandoned and destroyed nests and stratifie d by year to test for annual patterns of nest site selection. Quantification of L andscape S tructure and C omposition To derive landscape composition metrics, we converted the land cover map to a gridded raster with a spatial resolution of 30 meters. We us ed Fragstats 3.0 (McGarigal et al. 2002) to calculate the proportion of each land cover type around each cell within a circular moving window. We used 30m as the grid cell resolution to match the spatial resolution of the Landsat satellite sensor (NASA 2008) used to derive the land cover data (FFWCU 1994) The radius of the moving window was fixed at 157m corresponding to the radius described by a circle of an area equal to the mean core summer home range of bobwhites (7.724 0.731 ha, calculated as 50% Kernel density estimates of all radiolocations). Densities of linear features (road, road grade, food plots) were derived using the feature density function in ArcGIS 9.2 software. To derive landscape structure, we used a moving window approach similar to the one used for deriving landscape composition to calculate several landscape metrics from the gridded land cover map. Metrics with similar or overlapping behaviors were selected to build redundancy in the landscape structure information. The following m etrics were selected: aggregation, contagion, cohesion, interspersion and juxtaposition, percentage of like adjacencies, patch (McGarigal and Marks 1995, Riitters et al. 1996, Gustafs on 1998, He et al. 2000, McGarigal et al. 2002)

PAGE 42

42 Testing for the E ffect of L andscape C omposition and S tructure on N est S ite S election and N esting S uccess Preliminary analyses revealed that the landscape metrics were highly correlated. Thus, we first con ducted a principal component analysis (PCA) of landscape structure attributes, and variation in data (Clark et al. 1999) ; these 3 PCs were used for all subsequent analyses. Next, we compa red differences in landscape composition and structure around all nest locations and random points using MANOVAs. Finally, we modeled the probability of nest site selection as a function of landscape and habitat characteristics using logistic regression (Hosmer and Lemeshow 1989) We used MANOVA to test for differences in landscape structure and composition around successful and failed nests as desc ribed previously. Logistic regression was used to test for the influence of habitat and landscape features on the probability of nesting success. Results Nest S ite S election Of 365 nests monitored, 37.8% were located in dry prairie and 34.5% were locate d in pine palmetto habitats (Fig. 3 2). Distance ratios analyzed using the MANOVA procedure revealed that nesting habitat selection occurred, suggesting that some habitats were used more or less for nesting than could be expected by chance alone ( F = 5.81, P < 0.0001). Specifically, bobwhites preferred to place nests closer to food plots ( P < 0.0001) and farther away from water bodies ( P = 0.0003). Other habitat types were neither selected nor avoided (Table 3 2). Effect of H abitat C omposition and S tructu re on N est S ite S election The first three components (PC1 PC3) extracted from the principal component analysis of habitat and landscape structure variables explained 92.84% of the variation in the data. The patch

PAGE 43

43 cohesion and percentage of like adjacency metrics had high positive loadings on PC1 and explained 69.4% of the variation in the data. Contagion, interspersion and juxtaposition, and patch richness metrics had high positive loadings on PC2 and explained 13.18% of the variation. The aggregation and explained 10.18% of the variation in the data. We interpret PC1 as an index of connectedness between different land cover types in a given patch, PC2 as an index of highly aggregated yet diverse land cover types and PC3 in a manner similar to PC2 but with increased sensitivity to rare land cover classes. Nest sites differed significantly from random points in terms of habitat composition and landscape structure (Hoteling Lawley tra ce = 0.0192, F = 6.94, P < 0.0001). Among landscape composition variables, density of food plots ( F = 51.40, P < 0.0001; Fig. 3 3a), pine palmetto habitat ( F = 4.50, P = 0.034; Fig. 3 3b), density of roads ( F = 4.01, P = 0.045; Fig. 3 3a) and water ( F = 5. 32, P = 0.021; Fig. 3 3c) differed significantly between nest sites and random points. All landscape structure variables (PCs) differed significantly between random points and nest locations (all P < 0.01, Fig. 3 3d). The logistic regression model reveal ed that PC1 (an index of high interconnectedness of patches), PC2 (an index of diverse land cover types in the neighborhood of a site), density of food plots and pine palmetto habitat significantly influenced probability of nest site selection (all P < 0.0 5, Table 3 3). Factors I nfluencing N esting S uccess Only 56.99% ( n = 365) of nests we monitored were successful, and there was no obvious pattern of nesting success based on nesting habitat (Fig. 3 2). Nesting success did not differ 2 = 2.274, P 2 = 5.46, P = 0.362) or based on burn 2 = 3.88, P = 0.274).

PAGE 44

44 Neither the habitat composition nor landscape structure variables differed significantly between successful and failed nests (Hot eling Lawley trace = 0.0203, F = 0.65, P = 0.7811, Figure 3 4). Furthermore, logistic regression analysis revealed that none of the habitat composition or landscape structure variables significantly influenced probability of nesting success (all P > 0.05 ). Discussion The widespread declines in grassland bird populations across North America over the past decades have been widely documented, and loss and degradation of breeding habitats are suggested to have contributed to these declines (Askins 1993, Herkert 1995, Peterjohn and Sauer 1999) Loss and degradation of habitat also are thought to have contributed to the range wide declines in bobwhite populations (Brennan 1991, Di mmick et al. 2002, Sauer et al. 2004, Williams et al. 2004, Brennan and Kuvlesky 2005) An understanding of nesting habitat ecology, therefore, can help reverse the declining trends in bobwhite populations. Although bobwhite nesting ecology has been stu died in parts of their range (Taylor et al. 1999, Townsend et al. 2001, Lusk et al. 2006, Ransom et al. 2008) little is known about nest site selection, and factors influencing nest site selection and nesting succe ss in south Florida Our goal was to assist efforts to reverse the bobwhite population declines in south Florida by providing data on nesting ecology and selection of nest sites by bobwhites on Webb WMA. We found that bobwhites on Webb WMA preferred to pl ace nests significantly closer to food plots than would be expected by chance alone. Food plots are widely used management practices and are known to affect various aspects of bobwhite ecology (Sisson et al. 2000, Madison et al. 2000, W.E. Palmer, Tall Tim bers Research Station, pers. comm. 2009). Our findings are consistent with studies that have shown that food resources do influence nest site selection in bobwhites (e.g., Chalfoun and Martin 2007) and a number o f other bird species (e.g.

PAGE 45

45 pheasants Genovesi et al. 1999, bearded and griffon vultures Gavashelishvili and McGrady 2006) The fact that bobwhites in our study area preferred to nests in proximity of food plots, and also establish home ranges intersecting food plots (Singh et al., in review) suggest the fact that our study population may be experiencing food resource limitation. We speculate that strips of Sesbania offer provision of food and cover on the WMA where t he quality of habitat is generally suboptimal. Bobwhites preferred to nest farther away from water body, most likely to avoid the possibility of nest failure due to flooding (Applegate et al. 2002) Our results also revealed that nest sites differed significantly from random points in terms of habitat composition and l andscape structure. Specifically, nest sites were more likely to be found in patches where different habitat types were highly inter connected. Also, regions around nest locations were more likely to have a higher diversity of land cover types and better f ood resources (such as food plots). Our results are in agreement with those of Roseberry and (1998) (2005) in that landscape structural attributes influence nest site selection. These results also are consistent with the idea that results of nest site selection studies may depend on spatial scales (Kotliar and Wiens 1990 Orians and Wittenberger 1991, Clark et al. 1999) For example, when looking at actual location of nests, we found that bobwhites preferred to nest closer to food plots and farther away from water bodies; no other habitat was selected for or against. How ever, when we tested for the factors influencing nest site selection at local scales (habitat composition and landscape characteristics surrounding nest sites), it was evident and nest sites and random points differed significantly in terms of habitat comp osition and landscape structure variables (Table 3 2). These results have significant management implications because habitat management practices are generally implemented at

PAGE 46

46 scales larger than the location of nests, and also because they demonstrate the importance of the compositional and structural diversity of habitat in nest site selection by bobwhites. Nesting success was generally low in our study area (56.99%). There was no difference in nesting success among habitat types or years, and none of th e habitat or landscape variable we measured significantly influenced nesting success of bobwhites on the WMA. Studies investigating the effect of habitat and landcape attributes on nesting success have reported mixed results. For example Townsend et al. (2001) and Rader et al. (2007) found no evidence for the effect of nest site habitat attributes on nesting success, but Lusk et al. (2006) and Taylor et al. (1999) found that nests built under higher canopies and more shrub cover were more successful Chalfoun et al. (2007) have recently shown that, at the landscape scale, food availability may influence nesting success. The lack of evidence for the influence of habitat and landscape features on nesting success is suggestive of the fact that random nest predation by meso mammalian predators may be important in our study area, but we do not c urrently have conclusive evidence for it. We believe that nest fate in our study area is a more complex phenomenon that needs data beyond landscape attributes, and at multiple spatial scales.

PAGE 47

47 Table 3 1 Description of habitat types represented and area oc cupied by each habitat type in Babcock Webb Wildlife Management Area, Florida Habitat a Description Area (ha) %Area Dry Prairie (DP) Herbaceous and low shrub communities on seldom flooded, sandy soil areas very similar to pine palmetto, differing from t hem mainly by their lack of pines and sparse palmetto. Utilized by quail throughout the year for nesting, brood rearing, and roosting. 9736.96 36.308 Pine Palmetto (PP) Open stands of slash pine ( Pinus caribaea ) on poorly drained soils, with an understor y of saw palmetto ( Serenoa repens ), wire grass ( Aristida stricta ), broomsedge ( Andropogon spp .) and other grasses. Various panic grasses ( Panicum spp .), slough grass ( Scleria setacea ), and dwarf wax myrtle ( Cerothanmus pumilus ) are used by quail for feedi ng and/or nesting. 9145.19 34.101 Wetland prairie (WH) Herbaceous communities on low seasonally flooded transitional areas between permanent wetlands and drier communities. Important to quail primarily because of the abundant slough grass. Use is limited when they are flooded but commonly utilized when wet but not flooded. 7046.93 26.277 Odd Area (OA) Buildings and other human use areas not generally considered quail habitat. 508.09 1.895 Water (WA) Permanent ponds, natural and man made, surrounded by e mergent aquatic plants. 192.35 0.717 Food Plot (FP) Continuous serpentine stands of Sesbania sp ., an erect legume approximating 2 3 m in height. Width of the food plots is about 7 m. Ground cover beneath the plants is generally open and sandy. 151.21 0.56 4 Road Grade (RG) Roads prepared by grading to create a surface approximately 1+ m above the surrounding habitat. 18.75 0.07 Road (RD) Field roads not elevated above the surrounding surface 18.42 0.069 TOTAL 26817.9 0 100 .00 a Description of h abitat types adopted from Frye (1954), with modifications.

PAGE 48

48 Table 3 2 Results of t tests following MANOVA analyses testing for nest site selection. The t tests test for differences between the vector of ratios of the average distances of random points and distances of nest sites to each habitat type and a vector of 1s. Values of t statistic and associated P values are presented. Negative t statistics indicate that nest sites were found closer to the corresponding habitat type (in rows) than by chance, the magnitude of t statistics signifies the strength of the association. Non significant P values indicate the vector of ratios was not significantly different from a vector of 1s (no evidence of preference/avoidance). Significant P values are shown in bold ty peface. Habitat a t P Rank DP 0.41 0.679 4 FP 5.73 <.0001 1 OA 1.72 0.086 7 PP 1.52 0.129 6 RD 1.91 0.057 2 RG 0.29 0.769 5 WA 3.66 0.0003 8 WH 0.93 0.354 3 a D P = Dry Prairie, FP = Food Plot, OA = Odd Area, PP = Pine Palmetto, RD = Road, R G = Road Grade, WA = Water, WH = W etland prairie Table 3 3 Results of logistic regression analysis testing for the influence of habitat composition and landscape structure on nest site selection. S.E. P Intercept 2.583 0.095 741.693 <.0001 Principal component 1 0.076 0. 028 7.310 0.0069 Principal component 2 0.237 0.068 12.300 0.0005 Food plot density 37.136 10.542 12.407 0.0004 Percentage landscape pine palmetto 0.005 0.002 5.129 0.0235 Percentage landscape water 0.268 0.141 3.589 0.0582

PAGE 49

49 Figure 3 1 Location of the Webb Babcock Wildlife Management Area in Charlotte County, south Florida Five management zones are indicated by bold, upper case letters.

PAGE 50

50 Figure 3 2 Number of nests found in various land cover types arranged in ascending order stratified by nes t fate. Habitat type codes are: DP : D ry p rairie, FP = F ood p lot, OA = Odd a rea, PP = Pine p almetto, W P = W et land prairie. No nests were found in r oad, r oad g rade or water.

PAGE 51

51 Figure 3 3 Comparison of habitat composition and landscape structure ar ound random points and nest locations (means 1 SE) A ) D ifferences in linear feature density (road, road grade, and food plots, calculated within a 157 m window) B and C ) M eans of percentage land cover D ) means of sta ndardized principal compo nent scores for PCs 1, 2 and 3

PAGE 52

52 Figure 3 4 Comparison of habitat composition and landscape structure around successful and failed nests (means 1 SE) A ) D ifferences in linear feature density (road, road grade, and food plots, calculated within a 157 m window) B and C ) M eans of percentage land cover D ) means of sta ndardized principal compo nent scores for PCs 1, 2 and 3

PAGE 53

53 CHAPTER 4 CONCLUSIONS AND MANA GEMENT RECOMMENDATIO NS During the period of this study the bobwhite population on the majority of the Babcock Webb WMA existed at a very low density in contrast with many other managed habitats across (Dimmick et al. in press) The population reached this very low density exceeded 5000 birds per year (Florid a Fish and Wildlife Conservation Commission, unpublished data).The population decline almost surely reflected deterioration in the quality of the habitat, and this deterioration may have been facilitated by various changes in management practices as well a s other activities occurring on the area or its perimeter. It is also possible that the population has been over harvested, particularly during recent years when legal harvest removed birds at a rate believed to be unsustainable (Dimmick et al. in press) Efforts to reverse the downward spiral in the bobwhite population are currently underway. In this thesis, I examined several aspects of the spatia l ecology of bobwhite quail at the Babcock Webb WMA in South Florida. I estimated space use and habitat and nest site selection by bobwhites and investigated the influence of landscape composition and structure on bobwhite nesting success. My goal was to a ssist managers reverse the bobwhite population declines in south Florida by providing data on the habitat ecology and nesting ecology of bobwhites on the Babcock Webb WMA. Conclusions Literature review suggests that bobwhites typically occupy small home ranges ranging from approximately 5ha in excellent habitat to 40 ha in good habitat (Wiseman and Lewis 1981, Sisson et al. 2000 ; Bell et al. 1985, Dixon et al. 1996, Gu thery et al. 2004b, Haines et al. 2004, Terhune et al. 2006) The mean annual home range size in the Babcock Webb WMA was 88.43 6.16 ha, which is substantially larger than most previously reported bobwhite home ranges.

PAGE 54

54 E xtremely large bobwhite home ran ges observed in this study most likely reflects that some component of the habitat is poor on the WMA. Annual home ranges were generally smaller for birds whose ranges contained food plots compared to those that did not The fact that there were few home r anges that did not intersect food plots is itself an indication that food plots markedly influenced the habitat chosen by bobwhites on the WMA Furthermore, f ood plots significantly contributed to reduction in size of winter, but not summer, home ranges. B obwhites on Webb WMA preferred to place nests closer to food plots than would be expected by chance alone. The fact that bobwhites in the study area preferred to nests in proximity of food plots, and also establish home ranges intersecting food plots su ggest that the bobwhite population on the Webb WMA may be experiencing food resource limitation. I speculate that strips of Sesbania offer provision of food and cover on the WMA where the quality of habitat is generally suboptimal. The results revealed th at nest sites were more likely to be found in habitat patches where habitat diversity was high and different habitat types were highly inter connected. These results also suggest that results of nest site selection studies may depend on spatial scales (Kotliar and Wiens 1990, Orians and Wittenberger 1991, Clark et al. 1999) For example, when looking at actual location of nests, I found that bobwhites preferred to nest closer to food plots and farther away from wate r bodies However, when testing for factors influencing nest site selection at scales surrounding nest sites, it was evident that nest sites and random points differed significantly in terms of habitat composition and landscape structure. Nesting success was generally low in the study area (56.99%). There was no difference in nesting success among habitat types or years, and none of the habitat or landscape variable I measured significantly influenced nesting success of bobwhites on the WMA. The lack of

PAGE 55

55 e vidence for the influence of habitat and landscape features on nesting success is suggestive of the fact that random nest predation by meso mammalian predators may be important in our study area, but we do not currently have conclusive evidence for it. I b elieve that nest fate in our study area is a more complex phenomenon that needs data beyond landscape attributes, and at multiple spatial scales. Management R ecommendations Bobwhites in our study site had substantially larger home ranges compared to those in other parts of their range. If larger home ranges are indicative of lower habitat quality, as is typically assumed, the quality of habitat in our study site in south Florida may be considered suboptimal, most likely due to limited abundance of food res ources. There may be other habitat issues but food resources are clearly identified as an important factor by the data reported here. This is supported by the observation that bobwhites whose ranges contained food plots had substantially smaller home range s compared to those that did not, and that bobwhites exhibited a strong preference for food plots. M anagement practices that will lead to an increase in quantity and quality of food (e.g., through fertilization and rejuvenation) interspersed within well ma naged dry prairie and pine palmetto habitats will most likely have a positive impact on bobwhite populations in south Florida. This strategy would help release the bobwhite population from food limitations, while avoiding potential negative effects of high ly localized feeders (e.g. Frye 1954, Oberheu and Dabbert 2001) As the there are indications of food r esource limitation i t is not surprising that bobwhites generally established home ranges intersecting food plots, and preferred to place nests closer to food plots. Furthermore, the results point to the importance of a compositionally and structurally div erse habitat that can provide a diversity of food and cover resources throughout the year. Thus,

PAGE 56

56 management practices aimed at increasing quantity and quality of food plots (e.g., through fertilization and rejuvenation) interspersed within well managed pin e palmetto and other habitats that offer adequate food and cover will most likely have a positive impact on bobwhite population in South Florida. Guthery (1997) suggested that the goal of habitat management should be to maximize the proportion of landscape usable by bobwhites through time. Creation and maintenance of early successional native plant communities and augmentation of food a nd cover through food plots could contribute substantially to bobwhite population recovery in south Florida.

PAGE 57

57 LIST OF REFERENCES Aebischer, N. J., P. A. Robertson, and R. E. Kenward. 1993. Compositional analysis of habitat use from ani mal radio tracking data. Ecology 74:1313 1325. Allen, C. R., R. S. Lutz, and S. Demarais. 1995. Red imported fire ant impacts on northern bobwhite populations. Ecological Applications 5:632 638. Applegate, R. D., C. K. Williams, and R. S. Lutz. 2002. The e ffect of flooding on Northern Bobwhites. Western North American Naturalist 62:227 229. Askins, R. A. 1993. Population trends in grassland, shrubland, and forest birds in eastern North America. Current Ornithology 11:1 34. Badyaev, A. V., W. J. Etges, and T E. Martin. 1996. Ecological and behavioral correlates of variation in seasonal home ranges of wild turkeys. The Journal of Wildlife Management 60:154 164. Barea, L. P. 2008. Nest site selection by the painted honeyeater ( Grantiella picta ), a mistletoe sp ecialist. Emu 108:213 220. Barnes, T. G., L. A. Madison, J. D. Sole, and M. J. Lacki. 1995. An assessment of habitat quality for northern bobwhite in tall fescue dominated fields. Wildlife Society Bulletin 23:231 237. Begg, C. M., K. S. Begg, J. T. Du Toit and M. G. L. Mills. 2005. Spatial organization of the honey badger Mellivora capensis in the southern Kalahari: home range size and movement patterns. Journal of Zoology 265:23 35. Bell, B., K. Dancek, and P. J. Zwank. 1985. Range, movements, and habitat use by bobwhites in southern Louisiana pinelands. Proceedings of the Southeastern Association of Fish and Wildlife Agencies 39:512 519. Bingham, R. L., and L. A. Brennan. 2004. Comparison of Type I error rates for statistical analyses of resource selectio n. Journal of Wildlife Management 68:206 212. Boyce, M. S., and L. L. McDonald. 1999. Relating populations to habitats using resource selection functions. Trends in Ecology & Evolution 14:268 272. Brennan, L. A. 1991. How can we reverse the northern bobwhi te population decline. Wildlife Society Bulletin 19:544 555. Brennan, L. A., and W. P. Kuvlesky. 2005. North American grassland birds: An unfolding conservation crisis? Journal of Wildlife Management 69:1 13. Burger, L. W., D. A. Miller, and R. I. Southwic k. 1999. Economic impact of northern bobwhite hunting in the southeastern United States. Wildlife Society Bulletin 27:1010 1018.

PAGE 58

58 Chalfoun, A. D., and T. E. Martin. 2007. Assessments of habitat preferences and quality depend on spatial scale and metrics of fitness. Journal of Applied Ecology 44:983 992. Chapman, N. G., K. Claydon, M. Claydon, P. G. Forde, and S. Harris. 1993. Sympatric populations of muntjac ( Muntiacus reevesi ) and roe deer ( Capreolus capreolus ) a comparative analysis of their ranging beha vior, social organization and activity. Journal of Zoology 229:623 640. Clark, W. R., R. A. Schmitz, and T. R. Bogenschutz. 1999. Site selection and nest success of ring necked pheasants as a function of location in Iowa landscapes. Journal of Wildlife Man agement 63:976 989. Conner, L. M., M. D. Smith, and L. W. Burger. 2003. A comparison of distance based and classification based analyses of habitat use. Ecology 84:526 531. _____. 2005. A comparison of distance based and classification based analyses of ha bitat use: Reply. Ecology 86:3125 3129. Crabtree, R. L., L. S. Broome, and M. L. Wolfe. 1989. Effects of habitat characteristics on gadwall nest predation and nest site selection. The Journal of Wildlife Management 53:129 137. Dimmick, R. W. 1992. Northern bobwhite ( Colinus virginianus ). Dimmick, R. W., M. J. Gudlin, and D. F. Mckenzie. 2002. The northern bobwhite conservation initiative. South Carolina, USA. Dimmick, R. W., J. A. Hostetler, T. Hines, S. Brinkley, H. F. Percival, and M. K. Oli. in press. Hu nting pressure, harvest rates, mortality and survival of northern bobwhites in South Florida. Proceedings of the Game Bird Conference 2006. Dixon, K. R., M. A. Horner, S. R. Anderson, W. D. Henriques, D. Durham, and R. J. Kendall. 1996. Northern bobwhite h abitat use and survival on a South Carolina plantation during winter. Wildlife Society Bulletin 24:627 635. Elfstrom, M., J. E. Swenson, and J. P. Ball. 2008. Selection of denning habitats by Scandinavian brown bears Ursus arctos Wildlife Biology 14:176 1 87. Favaron, M., G. C. Scherini, D. Preatoni, G. Tosi, and L. A. Wauters. 2006. Spacing behaviour and habitat use of rock ptarmigan ( Lagopus mutus ) at low density in the Italian Alps. Journal of Ornithology 147:618 628. FenskeCrawford, T. J., and G. J. Nie mi. 1997. Predation of artificial ground nests at two types of edges in a forest dominated landscape. Condor 99:14 24. FFWCU. 1994. 1993/1994 Florida land cover. in Florida gap analysis project. Florida Fish and Wildlife Cooperative Unit,Gainesville, FL, USA.

PAGE 59

59 Fleming, K. K., and W. M. Giuliano. 2001. Reduced predation of artificial nests in border edge cuts on woodlots. Journal of Wildlife Management 65:351 355. Fretwell, S. D., and H. L. Lucas. 1970. On territorial behavior and other factors influencing habitat distribution in birds. Acta Biotheoretica 19:16 36. Frye, O. E. J. 1954. Charlotte county quail investigation. Report Project Florida W 11 R. Gavashelishvili, A., and M. J. McGrady. 2006. Breeding site selection by bearded vulture ( Gypaetus barbatu s ) and Eurasian griffon ( Gyps fulvus ) in the Caucasus. Animal Conservation 9:159 170. Genovesi, P., M. Besa, and S. Toso. 1999. Habitat selection by breeding pheasants Phasianus colchicus in an agricultural area of northern Italy. Wildlife Biology 5:193 20 1. Giuliano, W. M., C. R. Allen, R. S. Lutz, and S. Demarais. 1996. Effects of red imported fire ants on northern bobwhite chicks. Journal of Wildlife Management 60:309 313. Gustafson, E. J. 1998. Quantifying landscape spatial pattern: What is the state of the art. Ecosystems:143 156. Guthery, F. S. 1997. A philosophy of habitat management for northern bobwhites. Journal of Wildlife Management 61:291 301. Guthery, F. S., A. K. Crews, J. J. Lusk, R. N. Chapman, and M. Sams. 2004a. Effects of bag limits on bo bwhite hunters and harvest. Journal of Wildlife Management 68:1095 1103. Guthery, F. S., T. L. Hiller, W. H. Puckett, R. A. Baker, S. G. Smith, and A. R. Rybak. 2004b. Effects of feeders on dispersion and mortality of bobwhites. Wildlife Society Bulletin 3 2:1248 1254. Guthery, F. S., M. J. Peterson, and R. R. George. 2000. Viability of northern bobwhite populations. Journal of Wildlife Management 64:646 662. Haines, A. M., F. Hernandez, S. E. Henke, and R. L. Bingham. 2004. Effects of road baiting on home r ange and survival of northern bobwhites in southern Texas. Wildlife Society Bulletin 32:401 411. Hatchwell, B. J., A. F. Russell, M. K. Fowlie, and D. J. Ross. 1999. Reproductive success and nest site selection in a cooperative breeder: Effect of experienc e and a direct benefit of helping. Auk 116:355 363. He, H. S., B. E. DeZonia, and D. J. Mladenoff. 2000. An aggregation index (AI) to quantify spatial patterns of landscapes. Landscape Ecology 15:591 601. Heppell, S. S., H. Caswell, and L. B. Crowder. 2000 Life histories and elasticity patterns: Perturbation analysis for species with minimal demographic data. Ecology 81:654 665.

PAGE 60

60 Herkert, J. R. 1995. An analysis of midwestern breeding bird population trends: 1966 1993. American Midland Naturalist 134:41 50. Hernandez, F., F. Hernandez, J. A. Arredondo, F. C. Bryant, L. A. Brennan, and R. L. Bingham. 2005. Influence of precipitation on demographics of northern bobwhites in southern Texas. Wildlife Society Bulletin 33:1071 1079. Holt, R. D. 1985. Population dy namics in two patch environments: Some anomalous consequences of an optimal habitat distribution. Theoretical Population Biology 28:181 208. Hooge, P. N., and B. Eichenlaub. 2000. Animal movement extension to Arcview. ver. 2.0. in Alaska Science Center Biological Science Office, U.S. Geological Survey, Anchorage, AK, USA. Hosmer, D. W., and S. Lemeshow. 1989. Applied logistic regression. John Wiley & Sons, New York, New York, USA. Koehler, G. M., and D. J. Pierce. 2003. Black bear home range sizes in Washington: Climatic, vegetative, and social influences. Journal of Mammalogy 84:81 91. Kotliar, N. B., and J. A. Wiens. 1990. Multiple scales of patchiness and patch structure A hierarchical framework for the study of heterogeneity. Oikos 59:253 260. Lu sk, J. J., F. S. Guthery, and S. J. DeMaso. 2001. Northern bobwhite ( Colinus virginianus ) abundance in relation to yearly weather and long term climate patterns. Ecological Modelling 146:3 15. Lusk, J. J., S. G. Smith, S. D. Fuhlendorf, and F. S. Guthery. 2006. Factors influencing northern bobwhite nest site selection and fate. Journal of Wildlife Management 70:564 571. Madison, L. A., R. J. Robel, and D. P. Jones. 2002. Hunting mortality and overwinter survival of northern bobwhites relative to food plots in Kansas. Wildlife Society Bulletin 30:1120 1127. Martin, T. E. 1993. Nest predation and nest sites. BioScience 43:523 532. McGarigal, K., and B. J. Marks. 1995. FRAGSTATS: spatial pattern analysis program for quantifying landscape structure. Pacific Nort hwest Research Station. McGarigal, K., S. A. M. C. N. Cushman, and and E. Ene. 2002. FRAGSTATS: Spatial pattern analysis program for categorical maps. in A. University of Massachusetts, editor. www.umass.edu/landeco/research/fragstats/fragstats.html Moyer, M. A., J. W. McCown, and M. K. Oli. 2007. Factors influencing home range size of female Florida black bears. Journal of Mammalogy 88:468 476.

PAGE 61

61 Mueller, J. M., C. B. Dabbe rt, S. Demarais, and A. R. Forbes. 1999. Northern bobwhite chick mortality caused by red imported fire ants. Journal of Wildlife Management 63:1291 1298. NASA, L. p. 2008. Landsat Imagery. in G. L. C. Facility, editor. USGS/NASA,College Park, Maryland, US A. Ndithia, H., and M. R. Perrin. 2006. The spatial ecology of the rosy faced lovebird Agapornis roseicollis in Namibia. Ostrich 77:52 57. Oberheu, D. G., and C. B. Dabbert. 2001. Aflatoxin contamination in supplemental and wild foods of northern bobwhite. Ecotoxicology 10:125 129. Oka, T. 1992. Home range and mating system of 2 sympatric field mouse species, Apodemus speciosus and Apodemus argenteus Ecological Research 7:163 169. Orians, G. H., and J. F. Wittenberger. 1991. Spatial and temporal scales in habitat selection. American Naturalist 137:S29 S49. Parra, G. J. 2006. Resource partitioning in sympatric delphinids: Space use and habitat preferences of Australian snubfin and Indo Pacific humpback dolphins. Journal of Animal Ecology 75:862 874. Pedersen E. K., W. E. Grant, and M. T. Longnecker. 1996. Effects of red imported fire ants on newly hatched northern bobwhite. Journal of Wildlife Management 60:164 169. Perkins, M. W., and L. M. Conner. 2004. Habitat use of fox squirrels in southwestern Georgia. Journal of Wildlife Management 68:509 513. Peterjohn, B. G., and J. R. Sauer. 1999. Population status of North American grassland birds from the North American Breeding Bird Survey 1966 1996. Studies in Avian Biology 19:27 44. Peterson, M. J. 2001. Northe rn bobwhite and scaled quail abundance and hunting regulation: A Texas example. Journal of Wildlife Management 65:828 837. Pulliam, H. R. 1988. Sources, sinks and population regulation. American Naturalist 132:652 661. Rader, M. J., L. A. Brennan, F. Herna ndez, N. J. Silvy, and B. Wu. 2007. Nest site selection and nest survival of Northern bobwhite in Southern Texas. Wilson Journal of Ornithology 119:392 399. Ransom, D., R. R. Lopez, G. G. Schulz, and J. S. Wagner. 2008. Northern Bobwhite habitat selection in relation to brush management in the Rolling Plains of Texas. Western North American Naturalist 68:186 193. Riedle, J. D., R. C. Averill Murray, C. L. Lutz and D. K. Bolen. 2008. Habitat use by desert tortoises ( Gopherus agassizii ) on alluvial fans in the Sonoran Desert, south central Arizona. Copeia:414 420.

PAGE 62

62 Riitters, K. H., R. V. O'Neill, J. D. Wickham, and B. K. Jones. 1996. A note on contagion indices f or landscape analysis. Landscape Ecology 11:197 202. Robel, R. J., and K. E. Kemp. 1997. Winter mortality of northern bobwhites: Effects of food plots and weather. Southwestern Naturalist 42:59 67. Roseberry, J. L., B. J. Richards, and T. P. Hollenhorst. 1 994. Assessing the potential impact of conservation reserve program lands on bobwhite habitat using remote sensing, GIS, and habitat modeling. Photogrammetric Engineering and Remote Sensing 60:1139 1143. Roseberry, J. L., and S. D. Sudkamp. 1998. Assessing the suitability of landscapes for northern bobwhite. Journal of Wildlife Management 62:895 902. Saether, B. E., and O. Bakke. 2000. Avian life history variation and contribution of demographic traits to the population growth rate. Ecology 81:642 653. Sams on, C., and J. Huot. 1998. Movements of female black bears in relation to landscape vegetation type in southern Quebec. Journal of Wildlife Management 62:718 727. Sauer, J. R., J. E. Hines, I. Thomas, J. Fallon, and G. Gouch. 2004. The North American breed ing bird survey, results, and analysis, 1966 1999. United States Geological Service. Report Version 98.1. Seaman, D. E., and R. A. Powell. 1996. An evaluation of the accuracy of kernel density estimators for home range analysis. Ecology 77:2075 2085. Sisso n, D. C., H. L. Stribling, and D. W. Speake. 2000. Effects of supplemental feeding on home range size and survival of northern bobwhites in south Georgia. Pages 128 131 in Brennan, L.A., W.E. Palmer, L.W. Burger, Jr., and T.L. Pruden (eds) Quail IV: Proc. Fourth national Quail Symposium. Slade, N. A., L. A. Russell, and T. J. Doonan. 1997. The impact of supplemental food on movements of prairie voles ( Microtus ochrogaster ). Journal of Mammalogy 78:1149 1155. Stahl, J. T., and M. K. Oli. 2006. Relative i mportance of avian life history variables to population growth rate. Ecological Modelling 198:23 39. Sutherland, W. J. 1996. Predicting the consequences of habitat loss for migratory populations. Proceedings of the Royal Society of London Series B Biologic al Sciences 263:1325 1327. Taylor, J. S., K. E. Church, and D. H. Rusch. 1999. Microhabitat selection by nesting and brood rearing northern bobwhite in Kansas. Journal of Wildlife Management 63:686 694. Taylor, J. S., and F. S. Guthery. 1994. Components of northern bobwhite brood habitat in southern Texas. Southwestern Naturalist 39:73 77.

PAGE 63

63 Terhune, T. M., D. C. Sisson, H. L. Stribling, and J. P. Carroll. 2006. Home range, movement, and site fidelity of translocated northern bobwhite ( Colinus virginianus ) in southwest Georgia, USA. European Journal of Wildlife Research 52:119 124. Townsend, D. E., R. L. Lochmiller, S. J. DeMaso, D. M. Leslie, A. D. Peoples, S. A. Cox, and E. S. Parry. 1999. Using supplemental food and its influence on survival of northern bob white ( Colinus virginianus ). Wildlife Society Bulletin 27:1074 1081. Townsend, D. E., R. E. Masters, R. L. Lochmiller, D. M. Leslie, S. J. Demaso, and A. D. Peoples. 2001. Characteristics of nest sites of northern bobwhites in western Oklahoma. Journal of Range Management 54:260 264. Webb, W. M., and F. S. Guthery. 1983. Avian response to habitat management for northern bobwhites in northwest Texas. Journal of Wildlife Management 47:220 222. Whitaker, D. M., D. F. Stauffer, G. W. Norman, P. K. Devers, J. Ed wards, W. M. Giuliano, C. E. Harper, W. Igo, J. D. Sole, H. Spiker, and B. Tefft. 2007. Factors associated with variation in home range size of appalachian ruffed grouse ( Bonasa umbellus ). The Auk 124:1407 1474. White, C. G., S. H. Schweitzer, C. T. Moore, I. B. Parnell, and L. A. Lewis Weis. 2005. Evaluation of the landscape surrounding northern bobwhite nest sites: A multiscale analysis. Journal of Wildlife Management 69:1528 1537. White, G. C., and R. A. Garrott. 1990. Analysis of wildlife radio tracking data. Academic Press, San Diego, CA. Williams, C. K., F. S. Guthery, R. D. Applegate, and M. J. Peterson. 2004. The northern bobwhite decline: scaling our management for the twenty first century. Wildlife Society Bulletin 32:861 869. Wiseman, D. S., and J C. Lewis. 1981. Bobwhite use of habitat in tallgrass rangeland. Wildlife Society Bulletin 9:248 255. Worton, B. J. 1989. Kernel methods for estimating the utilization distribution in home range studies. Ecology 70:164 168. Xu, J. L., Z. W. Zhang, G. M. Z heng, X. H. Zhang, Q. H. Sun, and P. McGowan. 2007. Home range and habitat use of Reeves's pheasant Syrmaticus reevesii in the protected areas created from forest farms in the Dabie Mountains, central China. Bird Conservation International 17:319 330. Yo, S. P., Y. S. Lin, and W. E. Howard. 1992. Home range dynamics of red bellied tree squirrels ( Callosciurus erythraeus ) in Chitou. Bulletin of the Institute of Zoology Academia Sinica 31:199 211.

PAGE 64

64 Yoho, N. S., and R. W. Dimmick. 1972. Habitat utilization by b obwhite quail during winter. Pages 90 99 in J. A. Morrison, and J. C. Lewis, eds. Quail I: Proceedings of the First National Bobwhite Quail Symposium.:90 99.

PAGE 65

65 BIOGRAPHICAL SKETCH Aditya Singh was born in Indore, Madhya Pradesh, India in the year 1977 He graduated Gwalior, India in 2000. He received his Post graduate diploma in Planning from the Centre for Environmental Planning and Technology (CEPT), Ahmedabad, India in 2002. He worked at CEPT as a GIS, remote sensing and regional planning specialist for three years before joining the Ashoka Trust for Research in Ecology and the Environment (ATREE), Bangalore in 2005. At ATREE, he worked as a senior research asso ciate on issues related to biodiversity conservation planning in India. In August 2006, he began his graduate studies at the Department of Wildlife Ecology and Conservation at the University of Florida. Wildlife Ecology i n the spring of 2009.