The Ecology of Melanism in Yellow-Bellied Marmots of Grand Teton National Park: A summary of 1994 and 1995.

Abstract

Melanism (black fur coloration) in the yellow-bellied marmot, Marmota flaviventris, is encountered uniquely in the Teton Range in northwest Wyoming. During the summers of 1994 and 1995, several aspects involving marmots and melanism were investigated, including the affect of human impact on the incidence of melanism, spatial implcations of melansim, differential survival rates of melanistic and non-melanistic phenotypes, and temporal implications. Results suggest the the presence of humans is not related to the incidence of melanism when all surveyed areas of Grand Teton National Park are included in the analysis. However, when only those areas involving high human use and negligible human use are analyzed, then both the total number of marmots observed, and the proportion of melanistic marmots, are significantly higher in high human use areas. Differential survival rates of melanistic and non­melanistic phenotypes were observed for both 1994 and 1995 when comparing the proportions of marmots corresponding to the different age classes GuveniJes, subadults, and adults) for each pelage type (normal, melanistic, and other). Although 1994 and 1995 differed considerably with respect to the climate, only minute differences were observed in the proportions of the differnt pelage types and age groupings for the two years. Several interesting behaviors were documented including aboreal activity, resistance to snow exposure, tunneling in ice and under rock, thermoregulation by conduction, and kissing and paw play as a means of communication.