Rattlesnake migrations and the implications of thermal landscapes

Area of Science:

• Ecology
• Herpetology
• Conservation Biology

Background:

• Terrestrial ectotherms rely on thermal resources for survival and activity.
• Habitat selection by ectotherms, especially in colder climates, is often influenced by thermal attributes.
• Western rattlesnakes (Crotalus oreganus) in Canada are at their northern range limit, facing time constraints for migration.

Purpose of the Study:

• To investigate habitat use and migratory movements of Western rattlesnakes in relation to thermal landscapes.
• To examine coarse-scale differences in migratory patterns across the species' northern range.
• To compare snake migratory routes with thermal landscapes and ruggedness using GIS.

Main Methods:

• Radio-tracking of 35 male Western rattlesnakes from 10 different hibernacula.
• Analysis of migratory movements across the region.
• Comparison of snake routes with thermal landscapes and ruggedness GIS maps.

Main Results:

• Dichotomous habitat use observed: grasslands versus upland forests.
• Snakes from higher-elevation forests migrated further and utilized warmer landscape areas.
• Migratory movements varied based on the snakes' hibernacula.

Conclusions:

• Thermal benefits likely drive selective migratory patterns in Western rattlesnakes.
• Understanding population-specific migration strategies is vital for conservation planning and assessing landscape change impacts.
• Migratory patterns have implications for snake populations facing climate-induced ecosystem shifts.