Movement Behavior, Patch Occupancy, Sustainable Patch Networks and Conservation Planning for an Endemic Understory Bird
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MOVEMENT BEHAVIOR, PATCH OCCUPANCY, SUSTAINABLE PATCH NETWORKS AND CONSERVATION PLANNING FOR AN ENDEMIC UNDERSTORY BIRD By TRACI DARNELL CASTELLÓN A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2006 Copyright 2006 by Traci Darnell Castellón ACKNOWLEDGMENTS I sincerely thank my advisor, Kathryn Sieving, for her unwavering support and assistance, and my graduate committee, Lyn Branch, Michael Binford, Graeme Cumming, Doug Levey, and Emelio Bruna. I am also extremely grateful to my field assistants Hector Jañez, John Davis, Alvaro Wurstten, Emma Elgueta, Juan Carlos Correra, computer assistant Nia Haynes, and the many land owners in Chiloé and Osorno who graciously provided access to their farms. This work would not have been possible without their contributions. In addition, I have appreciated and benefited from the support of my friends and colleagues Daniel Smith, Mike Milleson, Matt Reetz, Tom Contreras, Nat Seavy, Marcella Machicote, Greg Jones, and Ivan Díaz. I gratefully acknowledge Mary Willson, Juan Armesto, and Cecilia Smith. Finally, and above all, I thank my parents; Carolyn Blethen and Charles Darnell, my husband Charles Castellón, and my friends, for helping me remember what is important. Partial funding was provided by the Disney Conservation Fund. In-kind support was provided by Fundación Senda Darwin, the University of Florida Map and Image Library, Geoplan Center, the Geography Department, the Land Use and Environmental Change Institute, and the Department of Wildlife Ecology and Conservation. iii TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................................................................................. iii LIST OF TABLES............................................................................................................. vi LIST OF FIGURES .......................................................................................................... vii ABSTRACT..................................................................................................................... viii CHAPTER 1 INTRODUCTION ........................................................................................................1 Theoretical Background................................................................................................2 Study System ................................................................................................................5 Research Overview.......................................................................................................8 2 AN EXPERIMENTAL TEST OF MATRIX PERMEABILITY AND CORRIDOR USE .......................................................................................................11 Introduction.................................................................................................................11 Methods ......................................................................................................................13 Study System.......................................................................................................13 Experimental Design ...........................................................................................15 Selection of Release Sites....................................................................................16 Capture and Handling..........................................................................................17 Radio Telemetry ..................................................................................................18 Measurement of Landscape Metrics....................................................................21 Data Analysis.......................................................................................................22 Results.........................................................................................................................23 Discussion...................................................................................................................27 Corridor versus Matrix Movement......................................................................27 Generality of Results ...........................................................................................28 Conservation Implications...................................................................................29 3 LANDSCAPE HISTORY AND FRAGMENTATION EFFECTS ON PATCH OCCUPANCY............................................................................................................36 Introduction.................................................................................................................36 Methods ......................................................................................................................38 Study System.......................................................................................................38 iv Land Cover Analysis ...........................................................................................40 Patch Occupancy Surveys ...................................................................................42 Habitat Quality Characterization.........................................................................43 Predictive Models................................................................................................45 Results.........................................................................................................................47 Land Cover Analysis ...........................................................................................47 Chucao Distribution Patterns...............................................................................47 Predictive Models................................................................................................48 Discussion...................................................................................................................49 Landscape Analysis.............................................................................................49 Chucao Distribution Patterns...............................................................................50 Model Validation.................................................................................................52 4 SUSTAINABLE PATCH-NETWORK CRITERIA ..................................................63 Introduction.................................................................................................................63 Methods ......................................................................................................................65 Study Species.......................................................................................................65 Landscape Criteria for Sustainable Populations..................................................65 Sustainable Population Size ................................................................................66 Habitat Area Requirements .................................................................................67 Matrix Composition and Connectivity ................................................................70 Sustainability Criteria Summary .........................................................................72 Graph Theory Format..........................................................................................73 Analysis of Test Landscapes ...............................................................................74 Results.........................................................................................................................75 Discussion...................................................................................................................76 Restoring Landscape Connectivity......................................................................80 Conclusions .........................................................................................................84 5 CONCLUSIONS AND RECOMMENDATIONS.....................................................91 Dissertation Summary ................................................................................................92 Conservation Implications and Recommendations ....................................................97 LIST OF REFERENCES.................................................................................................101 BIOGRAPHICAL SKETCH ...........................................................................................114 v LIST OF TABLES Table page 2-1. Summary of radio-telemetry results for translocated subjects .................................31 3-1. Metrics describing spatial patterns of forest cover in the Chiloé and Osorno study areas in 1961 and 1993. ..................................................................................56 3-2. Mean (± S.E.) values for metrics describing focal patches......................................58 3-3. Classification-tree model confusion matrices. .........................................................59 vi LIST OF FIGURES Figure page 2-1. Schematic representation of the three landscape treatments....................................33 2-2. Hazard function reflecting chance of movement by translocated Chucaos. ............34 2-3. Map (1:2,000) of wooded habitat patches................................................................35 3-1. Satellite image (grayscale)