PARENT SESSION
Oral Session # 58: Rare, Threatened, and Endangered Species III: Reptiles and Amphibians.
Presiding: K Beard
Wednesday, August 6. 1:30 PM to 5:00 PM, SITCC Meeting Room 202.

The common raven as a threat to esert tortoise, west Mojave Desert, California.

McIntyre, Blodwyn^*,1, ¹ University of Redlands, Redlands, CA, USA

ABSTRACT- The common raven (Corvus corax,) is a subsidized predator of the desert tortoise (Gopherus agassizii). Raven predation on juvenile tortoises is believed to be one of the most important threats to desert tortoise. Although many threats to the desert tortoise are known, few, including raven predation, have been quantified, which is essential to conservation management. An area in the West Mojave Desert encompassing five Breeding Bird Survey (BBS) routes was chosen for study. Raven population increases since the 1970's were calculated for this area. Using GIS, features in this landscape identified as "raven attractants" were quantified. Spatial and statistical analyses were used to estimate and rank the importance of various "raven attractants" (landfills, water sources, urban areas, etc.) in their potential to increase raven populations locally. The results of this study can be used in adaptive management of desert tortoise through management of "raven attractants".

Key words: Desert Tortoise (Gopherus agassizzi), Geographic Information Systems, Common Raven (Corvus corax), Threatened Species