Poster Session II
Project Type
Poster
Project Funding and Affiliations
American Society of Ichthyologists and Herpetologists and the Herpetologist’s League
Faculty Mentor’s Full Name
David Tevs
Faculty Mentor’s Department
Division of Biological Sciences
Abstract / Artist's Statement
Microhabitat selection by small ectotherms often involves trade-offs between accommodating the thermoregulatory needs of the organism and minimizing predation. Sunny microhabitats are often used as basking sites by small ectotherms. However, sunlight may also increase chromatic contrast between the animal and its substrate, thereby increasing visibility to potential predators. To counter this increased exposure, small ectotherms may develop means to remain hidden in sunny areas or achieving suitable body temperatures while in shaded areas. We collected data on substrate temperature, light conditions, observation time, and behavior (active vs stationary) between two sympatric garter snake species with contrasting dorsal colorations (Thamnophis elegans and Thamnophis sirtalis) in western Montana (USA). We observed the darker T. sirtalis more frequently in shaded areas and later in the day than the lighter T. elegans. However, substrate temperature at time of observation did not differ between the two species. We suspect T. elegans’ lighter coloration allows them to utilize sunny areas earlier in the day while decreasing interactions with T. sirtalis and remaining concealed to predators. In contrast, dark coloration on T. sirtalis may result in greater chromatic contrast with its substrate during sunny conditions. Consequently, T. sirtalis activity may be constrained to times of day when shaded areas provide both a means of crypsis and adequate thermoregulation.
Use of sunlight differs between sympatric garter snakes in montane riparian forests
UC South Ballroom
Microhabitat selection by small ectotherms often involves trade-offs between accommodating the thermoregulatory needs of the organism and minimizing predation. Sunny microhabitats are often used as basking sites by small ectotherms. However, sunlight may also increase chromatic contrast between the animal and its substrate, thereby increasing visibility to potential predators. To counter this increased exposure, small ectotherms may develop means to remain hidden in sunny areas or achieving suitable body temperatures while in shaded areas. We collected data on substrate temperature, light conditions, observation time, and behavior (active vs stationary) between two sympatric garter snake species with contrasting dorsal colorations (Thamnophis elegans and Thamnophis sirtalis) in western Montana (USA). We observed the darker T. sirtalis more frequently in shaded areas and later in the day than the lighter T. elegans. However, substrate temperature at time of observation did not differ between the two species. We suspect T. elegans’ lighter coloration allows them to utilize sunny areas earlier in the day while decreasing interactions with T. sirtalis and remaining concealed to predators. In contrast, dark coloration on T. sirtalis may result in greater chromatic contrast with its substrate during sunny conditions. Consequently, T. sirtalis activity may be constrained to times of day when shaded areas provide both a means of crypsis and adequate thermoregulation.