We evaluated the thermal ecology of Crotalus lutosus in a semi-arid montane landscape of eastern Nevada (Great Basin National Park). During 2023–2024, we surgically implanted 29 snakes with temperature dataloggers to record field active body temperature (Tb) and measured environmental temperatures in a wide range of available microhabitats. We determined the species’s preferred body-temperature range (Tset = 28–32°C) from previous studies and calculated thermoregulation indices to evaluate thermoregulatory effectiveness (E). We hypothesize that gravid females exhibit higher median Tb and greater E than non-gravid females and males, with more frequent exceedances of the upper bound (32°C) in midsummer. We expected the effectiveness of thermoregulation to peak in the early morning and late afternoon of the day, and then decline at dusk and night. We assumed snakes shift among microhabitats—basking in sun-exposed sites when the environment is cooler than their preferred body temperature range and retreating under rocks when the surrounding area is too warm. We further predicted that E will decline over time across the active season as ambient temperatures cool. This study linked microhabitat choice, thermal landscapes, and thermoregulatory metrics to clarify how C. lutosus maintains body temperatures within preferred thermal limits across time.

Colton recently graduated from the University of Nevada, Reno in December with a Master of Science degree in Natural Resources and Environmental Science. For his masters he studied rattlesnake habitat use and their thermal ecology. Colton has been an avid amphibian and reptile enthusiast since he was 6 years old and today, he strives to educate friends, family, colleaugues, and the public on the importance of amphibian and reptile conservation in Nevada, primarily human-rattlesnake conflict in towns, cities, and his favorite national park of all............ "Great Basin National Park!!!!"