Meeting Abstract
91.2 Wednesday, Jan. 7 Genetics vs. Environment: Variance in Torpor Patterns of Woodchucks along Latitudinal Gradients FENN, A.M.*; FLORANT, G.L.; ZERVANOS, S; Colorado State University; Colorado State University; Penn State University amfenn@simla.colostate.edu
Little is known about characteristics of torpor during hibernation at different latitudes. Woodchucks (Marmota monax) (WC), exhibit a variety of torpor patterns and have a population range from south-eastern United States to northern Alaska. To determine whether latitudinal gradient plays a role in torpor pattern characteristics, WC were obtained from 3 locales along a northern to southern gradient (Maine (WCM) (Latitude 43°42’N), Pennsylvania (WCP) (Latitude 40°22’N), and South Carolina (WCS) (Latitude 34°40’N)) and placed in a common room in Colorado (CO) (Latitude 40°45’N). Marmots (Marmota flaviventris) from CO were used as a reference out-group. WC were maintained in constant darkness at an ambient temperature (Ta) of 5° C. Body mass, body temperature (Tb) and food intake were recorded in all animals; during winter hibernation food was removed. We hypothesized that torpor characteristics would be similar among WC in the lab suggesting environmental conditions have a greater impact on torpor patterns than genetics. In the lab, WCM spent the most time at low Tb (2743.5 hrs) while WCS spent the least amount of time (1995 hrs). Time spent euthermic, number of torpor bouts, minimum and mean Tb and torpor bout length did not vary between populations. In comparison with field WC time in torpor, time euthermic, torpor bout length, and minimum and mean Tb appeared to differ with WC in the lab. Our data suggests that some traits such as date of final arousal and number of torpor bouts are more genetically fixed while traits such as minimum and mean Tb, torpor and euthermic bout length, and time euthermic vary with environment. These data support our hypothesis that the majority of torpor characteristics vary with environment suggesting high phenotypic plasticity.
