Meeting Abstract
Glucocorticoids are hormones that free up energy so that an organism can deal with a “stressor”. As addressed by the Reactive Scope Model (Romero et al. 2009), “stressors” can include predictive daily, seasonal, or lifetime changes with regard to the life history of the organism. For example, organisms may maintain elevated glucocorticoid levels during times of the year when they are more active, searching out mates or foraging. The objective of our study was to determine if individual timber rattlesnakes (Crotalus horridus) that maintain larger home ranges and increased movement rates at the same time of the year also maintain higher baseline glucocorticoid levels. We radio-tracked timber rattlesnakes (n = 20) for two years (2016 and 2017) and collected blood samples from individuals in August of each year. We determined corticosteroid levels for each blood sample using a competitive enzymeimmunoassay in the lab. We determined movement rates and home range sizes using radio locations for each individual within ArcGIS. We compared individual movement rates and home range sizes with baseline corticosterone levels using a mixed-model linear regression. Results from this study can assist biologists in interpreting the effect of behaviors on an animal’s physiology and further assist in the definition of a “stressor”.
