ECOLOGY AND CONSERVATION GENETICS OF RIDGWAY'S HAWK Buteo ridgwayi LANCE GERARD WOOLAVER JR. A DISSERTATION SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY GRADUATE PROGRAM IN BIOLOGY YORK UNIVERSITY TORONTO, ONTARIO JANUARY 2011 Library and Archives Bibliotheque et 1*1 Canada Archives Canada Published Heritage Direction du Branch Patrimoine de I'edition 395 Wellington Street 395, rue Wellington Ottawa ON K1A 0N4 Ottawa ON K1A 0N4 Canada Canada Your Tile Votre r6f6rence ISBN: 978-0-494-80558-9 Our file Notre reference ISBN: 978-0-494-80558-9 NOTICE: AVIS: The author has granted a non­ L'auteur a accorde une licence non exclusive exclusive license allowing Library and permettant a la Bibliotheque et Archives Archives Canada to reproduce, Canada de reproduire, publier, archiver, publish, archive, preserve, conserve, sauvegarder, conserver, transmettre au public communicate to the public by par telecommunication ou par I'lnternet, preter, telecommunication or on the Internet, distribuer et vendre des theses partout dans le loan, distribute and sell theses monde, a des fins commerciales ou autres, sur worldwide, for commercial or non­ support microforme, papier, electronique et/ou commercial purposes, in microform, autres formats. paper, electronic and/or any other formats. The author retains copyright L'auteur conserve la propriete du droit d'auteur ownership and moral rights in this et des droits moraux qui protege cette these. Ni thesis. Neither the thesis nor la these ni des extraits substantiels de celle-ci substantial extracts from it may be ne doivent etre imprimes ou autrement printed or otherwise reproduced reproduits sans son autorisation. without the author's permission. In compliance with the Canadian Conformement a la loi canadienne sur la Privacy Act some supporting forms protection de la vie privee, quelques may have been removed from this formulaires secondaires ont ete enleves de thesis. cette these. While these forms may be included Bien que ces formulaires aient inclus dans in the document page count, their la pagination, il n'y aura aucun contenu removal does not represent any loss manquant. of content from the thesis. 1+1 Canada ABSTRACT Ridgway's Hawk is a forest raptor endemic to the island of Hispaniola in the West Indies. The species is ecologically little known, with only three nests followed in 1976, and no comprehensive nest observations reported since then. This thesis reports on 5 years of research on the ecology and conservation genetics of this small isolated population. The global distribution was found to be limited to an area of 1600 km2 on the northeast coast of the island, with only one source population. Population size was estimated at 91 - 109 breeding pairs remaining with a continued declining trend observed over the study period. Effective population size for the species may be less than 40 individuals. Breeding pairs were found to be socially and genetically monogamous. Nests were constructed in native palm or hardwood trees, in areas with both intact secondary forest and small agricultural plots. Productivity averaged 0.64 young fledged per nest, similar to that of other tropical raptors. Nestling sex-ratio showed a trend toward female bias. Ridgway's Hawk relied on reptile prey for -80% of the diet as well as rats (9%) and smaller proportions of birds, frogs and arthropods. This specialist reptile diet provides insight into the current distribution of the species in the wet lowland forest of Los Haitises, where reptiles are abundant. Human activities including poaching of nestlings and habitat conversion within Los Haitises National Park are the main threats to the current population with sixty percent of nests monitored failing due to human activities. iv Genetic diversity within the population, based on 11 micro satellite loci, was found to be relatively high with a mean heterozygosity of 0.732. Deviations from Hardy-Weinberg equilibrium and linkage disequilibrium were found for several loci, with inbreeding as the most likely source of these deviations. Supporting evidence of inbreeding was verified by genetic relatedness estimators that showed 4 of 8 sampled pairings and up to 18% of potential pairings to be inbred. Conservation of the species is highly dependent on the protection of the remaining forested area of Los Haitises National Park. Although more intensive management will be required within the immediate future, high productivity and an ability to use human altered habitat has allowed this hawk to persist. If provided with a safe forested area, free from human persecution, and ample reptile prey, the population could recover. v ACKNOWLEDGEMENTS Firstly I would like to thank my co-supervisors, Bridget Stutchbury and Eugene Morton Thank you for advice and guidance over the five (plus) years, and comments on the chapters Thank you to Eugene for being such a genial mine of information, and to Bridget for persevering in the face of adversity (best way I can describe supervising someone like me), always being patient and positive, and extremely quick in replying any tune I needed help Thank you to Joel Shore and Laurence Packer for serving on my committee, providmg guidance, a sense of humour during my preliminary exam, and excellent comments on the chaptei s in this thesis Thank you to my parents and sister and to Bob and Frankie for always supporting Rina and I, and for unconditional support and love, which we are now able to pass on to Glen and Jeremy Thanks to Nigel Collar for making me aware of the plight of this beautiful hawk and the other fascinating birds of Hispamola, and for advice and moral support throughout Many thanks to Jim Wiley and Russell Thorstrom for sharing their knowledge of the hawk, as it proved invaluable Steve Latta and Chris Rimmer were extremely helpful, providing logistical support and a wealth of experience with carrying out research in Hispamola Robert Cmpley and David Wege provided valuable advice on working in the Caribbean A number of people have greatly assisted fieldwork in the Dominican Republic mcludmg Miguel Angel Landestoy, Jesus Almonte, Juan Cespedes, Nicolas Corona, Samuel VI Balbuena de la Rosa, Esteban Garrido, Damlo Mejia, Vemcio Mejia, and Maria Paulino Each of these individuals is quite special and we should all be grateful for the work they are doing on behalf of the unique wildlife of the Dommican Republic Tunoteo Bueno Hernandez (Timo), Pastor de Leon Franco (Chiverro) and Hilario Jorge Polanco (Nojime) provided significant conti lbutions to this thesis Their assistance during the field research, collecting observations and data at hawk nest sites was invaluable James Dean at the United States National Museum helped track down museum specimens fiom Haiti Thanks to Mike O'Brien, Marlene Snyder, Sheiman Boates and Soren Bondrup-Nielsen for assisting with funding applications, and Karen Freeman for providing advice during the write up Thank you to Heather Proctor for identifying nest parasites A special acknowledgement to Kate Wallace for all of her support thioughout Kate's passion and selfless concern for the birds of Hispamola is inspirational Thanks to Jason and Andrea Townsend (you guys rock) for helping me get my feet on the ground, and for being great company Jorge Brocca, Eladio Fernandez, Elvis Cuevas, Nicolas Corona, Pedro Rodriguez, Lrmbano Sanchez, and Yolanda Leon have each been of nnmense assistance on many occasions The Sociedad Orrntologica Hispamola (SOH) has been making a significant difference in saving species from extinction Jennie Smclair, Todd Nichols and John Vetter endured long, gruellmg hours of field-work without complamt, and proved to be excellent field researchers, providing important contributions to this thesis Elaine Williams and Ellen Rernhart (Wildlife Preservation Canada) and Graham Hallward provided much needed support back in Canada VII A number of people at York University have helped me along the way Bonnie Woolfenden and Scott Tarof at YUMEL provided me with the knowledge and skills to carry out the lab work, even when it was clear that I was not a natural This took some patience on their part. Even though it was a new experience, I enjoyed the tune in the lab and this was due in part to working with them At various times, other students helped me in the lab and I would like to thank the other YUMEL students Patrick Kramer, Ioana Chiver, Stephanie Hung, Tobin Macintosh, Tyler Done, and Elizabeth Gow for providing molecular tips along the way Amro Zayed and Jonathan Labonne shared their lab experience, while Amro provided excellent comments on the genetics chapter of this thesis A very large thank you to Adrienne Dome for helping me navigate my way through the University administration The research was partially funded by an NSERC award from 2005-2007 and an OGS in 2008 Fundmg for field and laboratory work was provided by Wildlife Preservation Canada's Canadian Collection, the James Bond Fund of the Smithsonian Institution, the Research Cost Fund at York University, and Dr Stutchbury's Molecular Ecology Lab at York University (YUMEL) In-kind support has been generously provided by Kate Wallace, Russell Thorstrom and The Peregrine Fund, the Sociedad Orrntologica Hispamola, Andrea and Jason Townsend, Chris Rimmer and Steve Latta All research was carried out with the permission of Subsecretaria de Estado de Areas Protegidas y Biodiversidad, and the Secretaria de Estado de Medio Ambiente y Recursos Naturales, Repubhca Domrmcana This work would never have been started or completed without Rina Nichols. Rina was there at the beginning when we first saw a Ridgway's Hawk together in Trepada Alta. We were hiking for hours through muddy quagmires in the rain, sleeping in a little tent surrounded by goats in the rain, but like so many other things in our life, we were there supporting each other together.