UC Riverside UC Riverside Electronic Theses and Dissertations Title How Predation Risk Shapes Avian Nest Site Selection and Processes Underlying Nest Predation Patterns Permalink https://escholarship.org/uc/item/1j85b9zn Author Latif, Quresh Shabbir Publication Date 2009 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA, RIVERSIDE How Predation Risk Shapes Avian Nest Site Selection and Processes Underlying Nest Predation Patterns A Dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Evolution, Ecology, and Organismal Biology by Quresh S. Latif December 2009 Dissertation Committee: Dr. John T. Rotenberry, Chairperson Dr. David Reznik Dr. Len Nunney Copyright by Quresh S. Latif 2009 The Dissertation of Quresh S. Latif is approved: _________________________________________ _________________________________________ _________________________________________ Committee Chairperson University of California, Riverside ACKNOWLEDGEMENTS I want to thank my advisor, John Rotenberry, and the current and past members of his lab for all their help and support. I especially thank Sharon Coe, Susana Peluc, and Karen Bagne for being available during particularly challenging times. I could not have carried out this research without my collaborator, Sacha Heath, and the numerous biologists, interns, and partners of the Eastern Sierra Program of PRBO Conservation Science. The Mono Basin Bird Chautauqua Research Grant, UC Riverside Graduate Research Improvement Grant, the UC Riverside Biology Department’s Distinguished Fellowship Program, and the UC Natural Reserve Program provided financial support either directly for this research or for my graduate school career. Inyo National Forest, USFS Region 5 Partners in Flight, California Department of Fish and Game, Oikonos, and the Advanced Energy Group provided video camera equipment for recording nest predation footage. The Los Angeles Department of Water and Power provided access to City lands along Rush Creek. I thank Johanna Rochester, Ritu Kapur, and Frank Johnson for donating finch eggs and the PRBO field crew for collecting old Yellow Warbler nests for use as experimental nests. I thank the U.C. Davis Museum of Wildlife and Fisheries Biology for use of their specimens for identification of clay egg bite impressions. I dedicate this dissertation to Marka Fenske (soon-to-be Marka Latif), Shabbir and Jumana Latif (my parents), all my friends and family. iv ABSTRACT OF THE DISSERTATION How Predation Risk Shapes Avian Nest Site Selection and Processes Underlying Nest Predation Patterns by Quresh S. Latif Doctor of Philosophy, Graduate Program in Evolution, Ecology, and Organismal Biology University of California, Riverside, December 2009 Dr. John T. Rotenberry, Chairperson Given the importance of nest predation to avian fitness, ornithologists expect birds to select nest sites that minimize predation risk. Despite numerous studies contributing to a wide body of literature, how predation shapes avian nest site selection is still not well understood largely because studies rarely examine the processes underlying either nest site selection or predation risk. I investigated how predation shapes nest site selection for a population of Yellow Warblers with an eye for the processes underlying observed patterns. From 2000-2008, 728 Yellow Warbler nests were monitored regularly until they either succeeded or were depredated (fieldwork was collaborative with PRBO Conservation Science). I measured microhabitat at nest sites (habitat use) and at randomly located sites (habitat availability) for analyses of habitat preference (use versus availability). I also monitored experimental nests (2006-2008) in sites that typically and atypically characterized Yellow Warbler nest sites, and I identified nest predators from v video footage recorded at nests and observations of predation recorded directly by field workers. I found conflicting evidence regarding the role of predation in shaping avian nest site selection. On the one hand, Yellow Warblers preferred high-predation nest microhabitat patches; preferred willow-dominated patches were positively correlated with predation rates (Chapter 2). On the other hand, Yellow Warblers preferred concealment levels (> 30%) that avoided predation risk, and even dynamically changed their selection patterns to favor low-predation sites when predation pressure changed (Chapter 3). Microhabitat-predation patterns primarily arose during the egg period (laying and incubation; Chapters 2, 3, 4) as a direct result on the predatory behaviors of either avian (mainly cowbird; Molothrus ater ) and/or rodent (chipmunks and mice) egg predators (identified in Chapter 1). Microhabitat-predation patterns were not confounded by coarser-scale predation patterns, which arose from different processes than did microhabitat-predation patterns (Chapter 4). These results suggest that Yellow Warblers are more capable of recognizing predator-free nest space with respect to nest concealment than microhabitat patch structure. Future research should examine the specific cues used by birds to select nest sites. Such research would further elucidate the limitations on the ability for nesting birds to recognize predator-free space. vi Table of Contents General Introduction .......................................................................................................1 References ..............................................................................................................7 Chapter 1. Nest predators in Mono Basin riparian systems and their predatory behavior Abstract ................................................................................................................10 Introduction ..........................................................................................................11 Methods ...............................................................................................................13 Results .................................................................................................................17 Discussion ...........................................................................................................20 References ...........................................................................................................26 Tables ..................................................................................................................30 Figures .................................................................................................................33 Chapter 2. An “ecological trap” for Yellow Warbler and its underlying processes Abstract ................................................................................................................34 Introduction ..........................................................................................................35 Methods ................................................................................................................38 Results ..................................................................................................................53 Discussion ............................................................................................................59 References ............................................................................................................68 vii Tables ...................................................................................................................74 Figures ..................................................................................................................78 Chapter 3. Evidence that “adaptive peaks” shape Yellow Warbler nest site selection Abstract ................................................................................................................81 Introduction ..........................................................................................................82 Methods ................................................................................................................85 Results ..................................................................................................................96 Discussion ..........................................................................................................104 References ..........................................................................................................113 Tables .................................................................................................................119 Figures ................................................................................................................123 Chapter 4. The role of Yellow Warbler parents in shaping patterns of nest predation risk Abstract ..............................................................................................................129 Introduction ........................................................................................................130 Methods ..............................................................................................................133 Results ................................................................................................................142 Discussion ..........................................................................................................149 References ..........................................................................................................158