Effects of feeding on body temperatures of rattlesnakes: A field experiment

I used temperature-sensing radiotransmitters to investigate the effect of feeding on body temperatures of rattlesnakes in the Sonoran Desert. Six snakes were fed meals (rodents) averaging 34% of their body mass. Snake locations and body temperatures were monitored before and after feeding in midautumn. Body temperatures of snakes that had eaten were compared with the body temperatures of unfed controls and with environmental temperatures. Rattlesnakes exhibited preferences for elevated body temperatures following feeding, but the degree, timing, and duration of this response varied considerably. At this rime of year, body temperatures of fed snakes were significantly higher than those of unfed controls only between 1200 and 1600 hours. The postfeeding thermophilic responses of snakes were restricted by thermal limitations in the snakes' environment and by reclusive behaviors following feeding. The elevated body tempera temperatures selected by snakes after feeding were similar to those maintained during activity.