BLUNT-NOSED BLING: ARE RADIO COLLARS A STRESSOR TO BLUNT-NOSED LEOPARD LIZARDS (GAMBELIA SILA)?
Heather M. Neldner; California Polytechnic State University, San Luis Obispo; 1262 Murray Avenue, #78, San Luis Obispo, CA, 93405; (310) 612-6808; hneldner@calpoly.edu; Michael Westphal, Ignacio T. Moore, Kathleen Ivey, Emily Taylor
The federally-endangered blunt-nosed leopard lizard (Gambelia sila) inhabits the rapidly disappearing San Joaquin Desert of California. A variety of techniques are employed to better understand the remaining populations of blunt-nosed leopard lizards, including deployment of radio collars around the lizards’ necks. Sublethal effects of radio collars may be detected by examining hormonal evidence of stress. Corticosterone (CORT) is a glucocorticoid hormone and mediator of stress, and high plasma CORT levels may suggest an animal is under some form of physiological stress. After the completion of a three month radiotelemetry project, we collected blood samples from twenty five collared and six uncollared blunt-nosed leopard lizards. To measure stress reactivity, or the rise in CORT from baseline following an acute stressor, lizards were placed inside breathable cotton bags for one hour, after which an additional blood sample was collected. We will present data comparing baseline CORT in blood samples from collared and uncollared lizards (to detect chronic stress) as well as stress reactivity (to examine the acute stress response). Examining these endocrine profiles will provide much-needed data on the extent to which radio collars may stress individual lizards, allowing us to refine our field methods for tracking sensitive species.
Poster Session