Behavior, Habitat Usage, and Status of Southwestern Speckled Rattlesnakes (Crotalus pyrrhus) in the

Grimsley, Ashley A.

agrimsley@azgfd.gov

Wildlife Contracts Branch

Arizona Game and Fish Department

Phoenix, Arizona, USA

Piest, Lin A.

Region 4

Arizona Game and Fish Department

Yuma, Arizona, USA

Jones, Tom R.

Terrestrial Branch

Arizona Game and Fish Department Phoenix, Arizona, USA

The Arizona Game and Fish Department is responsible for managing the wildlife resources in the State of Arizona. The Southwestern Speckled Rattlesnake (Crotalus pyrrhus) of the Tinajas Altas Mountains in Yuma County, Arizona, has a very light, attractive color variation that is not found anywhere else in the species’ distribution. The light variation of this snake occurs in a small area and is highly sought after in the pet trade. Limited data exist on the behavior, habitat usage, and status of this unique population. The Arizona Game and Fish Department conducted preliminary mark-recapture surveys from 2015 through 2017 in three separate canyons of the Tinajas Altas Mountains. Telemetry surveys were carried out in order to document the daily and seasonal activity and habitat usage of this snake, in the canyon suspected to have high traffic for collection. The study was carried out from fall of 2017 through spring of 2019. We captured snakes through visual encounter surveys throughout the study area and surgically implanted radio transmitters in a total of 19 snakes. During the active season (March through May) individual snakes were tracked twice a day, in morning, afternoon, or evening survey periods, to assess diurnal and nocturnal movement. Snakes were tracked less intensively from June through February. Telemetry data will be analyzed in May of 2019.