Turn of Events: How environmental temperatures and artificial nest habitats influence incubation behaviors of Cassin's auklets (Ptychoramphus aleuticus)

TURN OF EVENTS: HOW ENVIRONMENTAL TEMPERATURES AND ARTIFICIAL NEST HABITATS INFLUENCE INCUBATION BEHAVIORS OF CASSIN’S AUKLETS (PTYCHORAMPHUS ALEUTICUS) by Emily Cashman Kelsey Nest attendance behaviors are critical to hatching success for most bird species. Yet, details of avian incubation behaviors are still not well understood, especially for species that nest in burrows and crevices. Cassin’s auklet (Ptychoramphus aleuticus) is a burrow-­‐nesting seabird found throughout the northeastern Pacific Ocean, including Southeast Farallon Island, California (SEFI). Artificial nest boxes have been used to monitor Cassin’s auklets (hereafter auklet) breeding on SEFI. Temperatures in un-­‐ shaded nest boxes can increase significantly during extreme heat events. The effects of these elevated temperatures on auklet incubation behaviors and egg viability are not clear. In this study, egg data loggers were used to measure egg temperatures and turning rates of auklet eggs in natural burrows, shaded nest boxes, and un-­‐shaded nest boxes on SEFI during the 2012 and 2013 breeding seasons. Nest temperatures were highest and most variable in un-­‐shaded nest boxes. Egg temperatures were highest in un-­‐shaded boxes. Egg turning rates and egg temperature decreased during the night. During the day, egg turning rates increased with nest temperature. Overall, the results of this study show that nest habitat type can influence auklet incubation behaviors and temperatures. Increasing environmental temperatures could affect breeding Cassin’s auklets, and mechanisms to further mitigate these effects should be considered. v ACKNOWLEDGEMENTS First and foremost I would like to thank my adviser, Dr. Scott Shaffer for the opportunities, encouragement, and advice he has continually given me. I would also like to thank my committee members, Dr. Luis Bonachea and Dr. Jaime Jahncke for their support and instruction. I owe much gratitude toward Point Blue Conservation Science for their collaboration on this project, most importantly Pete Warzybok and Russ Bradley for their assistance in the field and out. I thank the US Fish and Wildlife Service for permission to conduct this work on SEFI, and the volunteer Farallon Patrol for providing transportation to and from the island. For help with my fieldwork I want to thank Ryan Berger, Sophie Webb, Ilana Nimz, Laney White, Scarlett Hutchin, Aniko Tutha, and all the other residents of SEFI during the 2012 and 2013 seabird seasons. I am appreciative of Corey Clatterbuck for our ongoing collaboration and grateful to the members of the ShAPE lab for their day-­‐to-­‐day support. I am indebted to Kat McKinnon and Philip Priolo of the Fine Art and Industrial Design departments at San Jose State University for creating the artificial eggs used in the project. For statistical advising, I would like to think Erika Taketa, Hongyue Song, and Xiangchao Qin of the Mathematics department at San Jose State University. I also would like to say thanks to Stephanie Flora of Moss Landing Marine Labs for her MATLAB wisdom. For funding for this project, I am grateful to the CSU COAST program, CSUPERB, The Myers Oceanographic and Marine Biology Trust, and San Jose State University Biological