Meeting Abstract

67.4  Wednesday, Jan. 6  Does Translocation Effect Physiological Stress Levels in Desert Tortoises? DRAKE, K.K.*; NUSSEAR, K.E.; ESQUE, T.C.; BARBER, A.; MEDICA, P.A.; TRACY, C.R.; U.S. Geological Survey; U.S. Geological Survey; U.S. Geological Survey; University of Nevada-Reno; U.S. Geological Survey; University of Nevada-Reno kdrake@usgs.gov

In 2005, the USGS initiated research to understand the physiological characteristics of stress potentially associated with translocation in a population of desert tortoises (Gopherus agassizii) near Fort Irwin, California. We hypothesized that translocation of wild tortoises may cause a potentially chronic physiological stress response in both resident and translocated animals and this response may result in changes in behavior, habitat use, and movement patterns. We predicted this stress response would return to baseline levels within two years after translocation. Blood samples (n=2,220) were collected from 238 individual tortoises for three years (2005-2007) prior to translocation and two years (2008-2009) post translocation to determine whether translocation of tortoises causes any measurable stress response, and the time frame over which animals adjust to translocation. Laboratory analyses were completed for samples (2005-2008) measuring plasma total corticosterone (CORT) using radioimmunoassay. Analysis for 2009 data are on-going. Sex, handling time, time of blood collection, animal body temperature, ambient air temperature, categories of lymphatic fluid (i.e. samples with no lymphatic fluid or samples containing <15% lymphatic fluid) all had a significant effect on levels of CORT. After translocation occurred in spring 2008, differences in CORT were not observed among treatment groups (translocated, resident, and control tortoises) indicating that translocation did not cause a measurable physiological stress response within the first year of translocation.