NESTING HABITAT SELECTION AND HABITAT ASSOCIATIONS OF JUVENILE JABIRU STORKS (Jabiru mycteria) IN BELIZE, CENTRAL AMERICA: IMPLICATIONS FOR CONSERVATION By OMAR ANTONIO FIGUEROA A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2005 Copyright 2005 by Omar Antonio Figueroa To Mary Elizabeth Figueroa. ACKNOWLEDGMENTS This research benefited tremendously from many individuals and organizations. First and foremost, my graduate advisor, Ken Meyer, provided encouragement, support, critical advice and consistent guidance. This project would probably still be conceptual if not for his partnership. My committee members, Peter Frederick and Scott Robinson, provided thoughtful comments. My study program at the University of Florida was funded by a Fulbright/Organization of American States Ecology Initiative Fellowship. Additional funding sources included a Compton Fellowship (Program for Studies in Tropical Conservation), a Jennings scholarship, the Protected Areas Conservation Trust, the Felburn Foundation, the Disney Wildlife Conservation Fund, the Wildlife Conservation Society, New Orleans Audubon Zoo, a Lewis A. Tyler Award and the Columbus Zoo Conservation Program. This generous support made my research possible. Several organizations in Belize provided crucial collaborative support. I would like to thank the Belize Forest Department for providing the necessary research permits, the Belize Zoo for allowing me to work on captive Jabiru storks and the Tropical Education Center for accommodations. The Belize Audubon Society, Programme for Belize and the Belize Forest Department allowed me to work on their managed lands. I thank Frank Plett and David Dueck for providing safe and reliable aerial surveys and Marcus Cucul for assistance with climbing and capture of juvenile Jabiru storks. iv I am indebted to many individuals for contribution too diverse and numerous to mention. I thank Osmany Salas, Sharon Matola, Tony Garel, Bruce and Carolyn Miller, Mark Myers, Marcelo Windsor, Hector Mai, John Pinelo, Valdemar Andrade, Richard and Carol Foster, Alejandro Paredes, Roberto Pott, Victor Alegria, Celso Pott, Miguel Choco, Mario Teul, Reynold Cal, Erneldo Bustamante, Norman Martinez, Joe Awe and Jonathan Urbina. I thank Wilber Martinez, an outstanding field companion, a genuine friend and a great field biologist who provided much needed assistance and encouragement during critical periods. His unwavering and selfless field assistance was greatly appreciated. I thank my wife Desi and daughter Rhiannon for their unrelenting support and understanding, especially during my prolonged absence in the past few months. I thank them for the lunch packs, warm meals and steadfast encouragement. I thank my brother and sisters, and their families for their support and for keeping in touch during challenging times. I am grateful to my parents, Arsenio and Jeanette, for things too numerous to mention. v TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................................................................................. iv LIST OF TABLES........................................................................................................... viii LIST OF FIGURES .............................................................................................................x ABSTRACT...................................................................................................................... xii CHAPTER 1 INTRODUCTION ........................................................................................................1 Regional Overview .......................................................................................................1 Habitat Selection...........................................................................................................2 The Study Species: The Jabiru Stork...........................................................................3 Distribution in Mesoamerica ........................................................................................4 2 METHODS...................................................................................................................7 Study Area ....................................................................................................................7 Nest Searching..............................................................................................................7 Microhabitat Vegetation Measurements.......................................................................9 Landscape-level Habitat Analysis ..............................................................................10 Landscape-level Spatial Analysis...............................................................................10 Nest Site Selection......................................................................................................12 Movement...................................................................................................................15 Habitat Use Versus Available.....................................................................................16 Home-range Analysis .................................................................................................19 National and Regional Queries...................................................................................19 3 RESULTS...................................................................................................................25 Nest Site Selection......................................................................................................25 Microhabitat and Landscape Measurements ..............................................................25 Nest Sites and Ecosystems..........................................................................................28 Habitat Use Versus Availability .................................................................................29 Nest Sites.............................................................................................................29 Post Fledging Movement.....................................................................................29 vi Habitat Associations of Juvenile Storks..............................................................30 Nest Sites by Protected Areas, Watershed Regions and Political Boundaries ...........31 Home Range, Protected Areas and Watershed Regions.............................................32 National and Regional Queries...................................................................................32 4 DISCUSSION.............................................................................................................57 Movement...................................................................................................................63 Conservation Implications..........................................................................................64 Directions for Future Study ........................................................................................66 5 CONCLUSION...........................................................................................................69 LIST OF REFERENCES...................................................................................................73 BIOGRAPHICAL SKETCH .............................................................................................78 vii LIST OF TABLES Table page 1 Broad scale ecosystem classes for Belize. ...............................................................24 2 Comparisons of microhabitat variables measured for nest trees and randomly selected over story trees, and comparisons for landscape measurements at nest and random sites.......................................................................................................35 3 Species and relative percentage of eighty randomly selected unused (over story) trees within 180 meters of 22 active Jabiru stork nests............................................37 4 Principal component analysis (PCA) of variation along landscape variables measured for random sites (a) and nest sites (b).. ....................................................38 5 Principal component analysis (PCA) of variation along microhabitat variables for nest trees (a) and random trees (b)......................................................................38 6 Comparisons of ecosystems within which Jabiru storks built nests and the associated nearest ecotone with those of randomly selected points.........................42 7 Relative frequencies of ecotones associated with Jabiru stork nest sites and random sites..............................................................................................................43 8 Comparisons of habitat use (within 3000 m buffers of nest sites) to the proportions of available habitat within the 3000 m buffered MCP polygon for all nest sites. ..................................................................................................................45 9 Results of Chi square analyses showing that juvenile Jabiru storks used tropical lowland tall herbaceous swamps and short grass savanna with shrubs more than expected....................................................................................................................47 10 Results of the spatial cluster analysis procedure used to test the hypothesis that the activity pattern displayed