Stable isotope values suggest opossums (Didelphis virginiana) at their northern edge do not seasonally molt

Abstract

The Virginia opossum (Didelphis virginiana) continues to spread further north into temperate North America, raising questions regarding how they survive harsh winters. Very few marsupials exhibit winter adaptations such as torpor or seasonal molting. We used stable isotopes to evaluate evidence of seasonal molting in opossums. We serially cut hairs from captive opossums to determine if a documented diet shift early in life was reflected along the hair shaft. Isotope values along the hair mirrored a shift in captive opossum’s diets. We compared isotope values between opossums trapped in different seasons and found no differences. The data indicate opossums do not seasonally molt at the northern edge of their range.