California Condors in the Pacific Northwest: Integrating History, Molecular Ecology, and Spatial Modeling for Reintroduction Planning
Total Page:16
File Type:pdf, Size:1020Kb
AN ABSTRACT OF THE DISSERTATION OF Jesse D’Elia for the degree of Doctor of Philosophy in Wildlife Science presented on December 8, 2014. Title: California Condors in the Pacific Northwest: Integrating History, Molecular Ecology, and Spatial Modeling for Reintroduction Planning Abstract approved: ________________________________________________ Susan M. Haig Reintroduction programs are increasingly being used to save animals from extinction and aid in their recovery. The California Condor (Gymnogyps californianus), one of the most endangered birds in the world, is a remarkable example of how reintroduction programs can help rapidly increase a species’ population numbers and range following a population bottleneck. Despite these gains, condors remain a critically endangered species and are absent from the northern half of their historical range. Here I evaluated questions concerning the biological feasibility of reintroducing California Condors to their former range in the Pacific Northwest using a multidisciplinary approach, employing the fields of history, molecular ecology, and spatial modeling. A review of the historical evidence, including the archeological and paleontological record, use of condors in Native American culture, and early historical accounts of explorers and naturalists, suggest that condors were once widely distributed and likely abundant in the Pacific Northwest. It is also likely that they were breeding birds in the region, rather than seasonal migrants. Examination of 526 base pairs from the control region of mitochondrial DNA (mtDNA) harvested from California Condor museum samples (n = 67) and genetic founders of the captive population (n =14) revealed 18 haplotypes in the historical population, 14 of which have not been reported previously. Only three of these haplotypes survived the genetic bottleneck, indicating > 80% reduction in haplotype richness. This substantial loss of genetic diversity is consistent with the hypothesis that condor populations were relatively abundant at the time of Euro-American contact, but declined rapidly as a result of human causes. I found no spatial sorting of haplotypes in the historical population, which suggests historical gene flow between the Pacific Northwest and southern and central California. Therefore, conservation strategies should consider restoring rangewide metapopulation connectivity when planning future reintroductions. Finally, I developed and tested activity- specific ecological niche models (nesting, roosting, and feeding) to identify areas in the Pacific Northwest that have retained ecological characteristics similar to those where condors have been observed in the last several decades. These models were integrated with information on condor movement ecology and biology to produce predictive maps of reintroduction site suitability across California, Oregon, and Washington. Ecological niche models were consistent with published knowledge of California Condor ecology, had good predictive performance when tested with data withheld from model development, and identified several candidate reintroduction areas. Results suggest that > 70% of the modeled nesting habitat and > 60% of the modeled roosting and foraging habitat in Washington, Oregon, and California is currently unoccupied. Thus, there are large unoccupied regions of the California Condor’s historical range in the Pacific Northwest that still possess relevant ecological features similar to currently occupied habitats, and therefore warrant consideration for future reintroduction efforts. In summary, this study provides foundational information to inform condor reintroductions to the Pacific Northwest. Key findings include: (1) extensive evidence that condors previously occupied the Pacific Northwest, likely in large numbers, prior to Euro-American expansion; (2) the lack of historical population structure, suggestive of historical gene flow between condor populations in the Pacific Northwest and elsewhere in the range; and, (3) identification of several candidate reintroduction areas in the Pacific Northwest that have retained environmental conditions that appear suitable for condor recovery. ©Copyright by Jesse D’Elia December 8, 2014 All Rights Reserved California Condors in the Pacific Northwest: Integrating History, Molecular Ecology, and Spatial Modeling for Reintroduction Planning by Jesse D’Elia A DISSERTATION submitted to Oregon State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Presented December 8, 2014 Commencement June 2015 Doctor of Philosophy dissertation of Jesse D’Elia presented on December 8, 2014. APPROVED: _________________________________________________ Major Professor, representing Wildlife Science _________________________________________________ Head of the Department of Fisheries and Wildlife _________________________________________________ Dean of the Graduate School I understand that my dissertation will become part of the permanent collection of Oregon State University libraries. My signature below authorizes release of my dissertation to any reader upon request. _________________________________________________ Jesse D’Elia, Author ACKNOWLEDGEMENTS The work of conceiving, carrying out, and completing this dissertation was far from a solo endeavor. I am indebted to so many people for offering their time, assistance, data, encouragement, knowledge, and patience as I navigated this odyssey. First, I thank my family for their unmitigated love and support - my grandparents, for their wisdom and for setting an amazing example that I try to live up to every day; and, my parents, Ralph and Barbara D’Elia for their through-and-through love, support, and encouragement — no matter what. Thanks also to my three brothers, Jay, Ryan, and Matt for their always present comradery and advice over the years. To my wife Courtney, no words can express the gratitude for all of the sacrifices you’ve made while I was on this adventure. You have been my rudder in rough seas, my sail in the wind, and my sun on a calm day. And, to my children - who will never fully understand how much of what I do is for you (no matter how many times I tell you). Thank you. I love you. I thank my advisor and mentor Dr. Susan Haig for suggesting I focus my research on California Condors and for providing exceptional encouragement, support, and guidance. Thanks also the other members of my committee—Dr. Matthew Betts, Dr. Clint Epps, Dr. Matthew Johnson, and Dr. Bruce Marcot—who provided excellent feedback on my study plan and earlier drafts of this dissertation and its component parts. This work is vastly improved as a direct result of your contributions. Thanks also to my Graduate Council Representatives to the committee, Dr. Frank Tepley, and Dr. Daniel Luoma. In addition to committee members, there are other individuals that deserve special mention. Thanks to Sanford Wilbur, principal condor researcher from 1970 to 1980, for his role as a key source of information on the historical occurrence records of California Condors in the region, something he has been investigating for decades. Thanks also to Dr. Noel Snyder, principal condor researcher in the 1980s, for suggesting several important corrections and additions to the chapter on the history of California Condors in the Pacific Northwest that made the dissertation more accurate and complete. Jan Hamber, in addition to being one of the nicest people I’ve ever met, was extremely generous with her time and her firsthand knowledge of the history of the condor recovery program and the extensive files she keeps at the Santa Barbara Museum of Natural History were most helpful and interesting. I also thank Jesse Grantham, California Condor Recovery Coordinator (2004–2012), for stimulating discussions on condor ecology and hosting me on a number of occasions to view condors in the wild and to sift through the official condor recovery files housed at the US Fish and Wildlife Service’s Condor Recovery Office in Ventura, California. Many other people deserve recognition for sharing their knowledge of California Condors and guiding me see condors in the wild. For this I thank Joseph Brandt, Joe Burnett, Eddie Feltes, Daniel George, Chris Parish, Scott Scherbinski, Kelly Sorensen, and Mike Tyner. Finally, I must thank all of my coworkers and mangers at the U.S. Fish and Wildlife Service for their encouragement and support for this research. I especially thank Ren Lohoefener, Robyn Thorson, Richard Hannan, Theresa Rabot, Paul Henson, Patrick Sousa, John McCamman, Scott McCarthy, Marilet Zablan, and Kit Hershey. Support for this work was provided by the Oregon State University Graduate School’s Laurels Block Grant, the Delson Bridge to the Future Fund, the U.S. Fish and Wildlife Service, and U.S. Geological Survey Forest and Rangeland Ecosystem Science Center. CONTRIBUTION OF AUTHORS This study was performed in the laboratory of Dr. Susan M. Haig who provided financial support, advice, and assisted with the organization and development of this dissertation. All laboratory work for Chapter 3 was performed by Tom Mullins and his staff in Dr. Susan Haig’s genetics lab. Dr. Mark Miller, also in Susan Haig’s lab, assisted with statistical analyses for Chapter 3. Dr. Susan Haig, Dr. Matthew Johnson (USDA Plumas National Forest), and Dr. Bruce Marcot (USDA Pacific Northwest Forest Research Station) assisted with study design for Chapter 4. Dr. Johnson also assisted in acquiring spatial data for atmospheric variables. Rich