29th Annual Meeting and Symposium of the
Desert Tortoise Council, February 20-23, 2004
Abstracts

POSTER

Preliminary Distribution of Upper Respiratory Tract Disease in Captive and Free-ranging Desert Tortoises in Greater Tucson, Arizona

Cristina A. Jones^1,2, Cecil R. Schwalbe^3,1, Don E. Swann⁴ and William W. Shaw^1
1School of Renewable Natural Resources, The University of Arizona, 325 Biological Sciences East, Tucson, AZ 85721
²Arizona-Sonora Desert Museum, Department of Herpetology, Ichthyology, and Invertebrate Zoology, 2021 N. Kinney Road, Tucson, AZ 85743
³U.S. Geological Survey, Southwest Biological Science Center, Sonoran Desert Research Station, The University of Arizona, 125 Biological Sciences East, Tucson, AZ 85721
⁴Saguaro National Park, 3693 S. Old Spanish Trail, Tucson, AZ 85730.

Upper Respiratory Tract Disease (URTD), caused by the pathogen Mycoplasma agassizii, poses a critical threat to the Mojave population of the desert tortoise (Gopherus agassizii), where release of captive tortoises into the wild has been implicated in the spread of the disease. Little is known about URTD in the Sonoran population of the desert tortoise. To determine the distribution of URTD in Greater Tucson, Arizona we used enzyme-linked immunosorbent assay (ELISA) to detect antibodies indicating previous exposure to M. agassizii. Blood samples were collected in 2002 and 2003 from 52 captive tortoises within Tucson and 117 free-ranging tortoises in 9 mountain ranges along an urban gradient radiating from Tucson. We compared results from captive and free ranging populations to determine if there is an association between urbanization and distribution of M. agassizii. Results of this study will shed light on geographic patterns of URTD and may help elucidate the relationship between a very large captive population and free-ranging population. This study has implications for other diseases that may be spread into urban wildlife habitat as human development continues to encroach upon mountain foothills.