Effects of Human Activity and Predation on Breeding American

0058227 EFFECTS OF HUMAN ACTIVITY AND PREDATION ON BREEDING AMERICAN OYSTERCATCHERS by JOHN B. SABINE, III (Under the Direction of J. Michael Meyers and Sara H. Schweitzer) ABSTRACT The United States population of American Oystercatchers (Haematopus palliatus) is of special concern. Biologists attribute low numbers and reduced reproductive success to excessive predation and human disturbance; however, researchers have not documented nest predators positively and the mechanism by which human presence reduces reproductive success is not well understood. During the 2003 and 2004 breeding seasons, I video-monitored American Oystercatcher nests (n = 32) to document causes of nest failure and observed oystercatcher behavioral responses to human activity at Cumberland Island National Seashore. Hatching and fledging success were 45% and 33%, respectively. Predation was the primary cause of nest failure (44% of nests). Pedestrian activity reduced reproductive behavior during incubation. Vehicular activity reduced foraging behavior during brood rearing. Presence of boats did not affect behavior. Oystercatchers were fairly intolerant of pedestrian activity ≤137 m of nests during incubation. During brood rearing, oystercatchers reacted to pedestrian activity ≥137 m of chicks. INDEX WORDS: American Oystercatcher, behavior, Cumberland Island, Georgia, Haematopus palliatus, human disturbance, predation, reproductive success, shorebirds, time activity budget, video monitoring 0058228 EFFECTS OF HUMAN ACTIVITY AND PREDATION ON BREEDING AMERICAN OYSTERCATCHERS by JOHN B. SABINE, III B.S., Furman University, 2000 A Thesis Submitted to the Graduate Faculty of The University of Georgia in Partial Fulfillment of the Requirements for the Degree MASTER OF SCIENCE ATHENS, GEORGIA 2005 0058229 © 2005 John B. Sabine, III All Rights Reserved 0058230 EFFECTS OF HUMAN ACTIVITY AND PREDATION ON BREEDING AMERICAN OYSTERCATCHERS by JOHN B. SABINE, III Major Professor: J. Michael Meyers Sara H. Schweitzer Committee: Robert J. Cooper Karl V. Miller James R. Richardson Electronic Version Approved: Maureen Grasso Dean of the Graduate School The University of Georgia August 2005 0058231 ACKNOWLEDGEMENTS I would like to begin by thanking my advisors, Joe Meyers and Sara Schweitzer for creating this research project and giving me the opportunity to carry it out. I could not have asked for more supportive, inspirational, and insightful advisors. I am forever indebted to the woman in my life, Erin Reno. You always had an open ear to my ravings about oystercatchers and your words of encouragement kept me going even when the birds crept into my nightmares. Without your blood and sweat in the field, this project would not be what it has become. My parents edited thesis chapters, helped in the field, gave me a job when I was unemployed, and were an endless source of support and love. Thanks to my committee members, Bob Cooper, Karl Miller, and Jim Richardson, for advice on project design and thesis editorial comments. Without the statistical genius of Clint Moore, I would have drowned in a sea of mixed models and covariance matrices. The help of field technicians Sharon Valitzski, Jennifer Chastant, and Michael Nichols was invaluable. John Fry, Bert Rhyne, and the staff at Cumberland Island National Seashore welcomed me warmly to the island and, along with Brad Winn of the Georgia Department of Natural Resources, provided logistical support and advice that were critical to the success of this project. The USGS Species-at-Risk Program provided substantial funding. I thank the Georgia Ornithological Society, Cumberland Island Conservancy, the University of Georgia’s Stoddard-Burleigh-Sutton Committee, and the D. B. Warnell School of Forest Resources for additional funding. iv 0058232 TABLE OF CONTENTS Page ACKNOWLEDGEMENTS............................................................................................... iv LIST OF TABLES........................................................................................................... viii LIST OF FIGURES ........................................................................................................... ix CHAPTER 1 INTRODUCTION .............................................................................................1 LIFE HISTORY.................................................................................................2 STATUS AND CONSERVATION .........................................................................8 STUDY OVERVIEW........................................................................................10 LITERATURE CITED ......................................................................................10 2 A SIMPLE, INEXPENSIVE VIDEO CAMERA SETUP FOR THE STUDY OF AVIAN NEST ACTIVITY ...................................................................15 ABSTRACT....................................................................................................16 INTRODUCTION.............................................................................................16 METHODS .....................................................................................................17 RESULTS.......................................................................................................19 DISCUSSION..................................................................................................20 ACKNOWLEDGEMENTS .................................................................................22 LITERATURE CITED ......................................................................................22 v 0058233 3 NEST FATE AND PRODUCTIVITY OF AMERICAN OYSTERCATCHERS, CUMBERLAND ISLAND NATIONAL SEASHORE, GEORGIA ............................................................................26 ABSTRACT....................................................................................................27 INTRODUCTION.............................................................................................28 STUDY AREA ................................................................................................29 METHODS .....................................................................................................30 RESULTS.......................................................................................................32 DISCUSSION..................................................................................................33 ACKNOWLEDGEMENTS .................................................................................37 LITERATURE CITED ......................................................................................38 4 EFFECTS OF HUMAN ACTIVITY ON BEHAVIOR OF BREEDING AMERICAN OYSTERCATCHERS, CUMBERLAND ISLAND NATIONAL SEASHORE, GEORGIA.......................................................44 ABSTRACT....................................................................................................45 INTRODUCTION.............................................................................................46 STUDY AREA ................................................................................................48 METHODS .....................................................................................................49 RESULTS.......................................................................................................55 DISCUSSION..................................................................................................57 MANAGEMENT IMPLICATIONS ......................................................................63 ACKNOWLEDGEMENTS .................................................................................63 LITERATURE CITED ......................................................................................64 vi 0058234 5 CONCLUSIONS..............................................................................................78 REPRODUCTIVE SUCCESS AND PRODUCTIVITY .............................................78 THREATS TO REPRODUCTIVE SUCCESS.........................................................79 MANAGEMENT RECOMMENDATIONS............................................................85 RECOMMENDATIONS FOR FUTURE RESEARCH..............................................88 LITERATURE CITED ......................................................................................89 APPENDIX A American Oystercatcher clutch data from Cumberland Island National Seashore, Georgia, 2003 and 2004..............................................................93 B Mean presence (%) of human activities near American Oystercatcher nest attempts (± 2 SE) during incubation, Cumberland Island National Seashore, Georgia, 2003 and 2004..............................................................94 C Mean presence (%) of human activities near American Oystercatcher nest attempts (± 2 SE) during brood rearing, Cumberland Island National Seashore, Georgia, 2003 and 2004..............................................................96 D Mean time (%) devoted to behaviors by American Oystercatcher pairs (± 2 SE) during incubation, Cumberland Island National Seashore, Georgia, 2003 and 2004 ..............................................................................97 E Mean time (%) devoted to behaviors by American Oystercatcher pairs (± 2 SE) during brood rearing, Cumberland Island National Seashore, Georgia, 2003 and 2004 ..............................................................................99 vii 0058235 LIST OF TABLES Page Table

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