Two Fields, One Pellet: Combining Demographics and Population Genetics Through Non-invasive Sampling of Snowshoe Hare Fecal Pellets in Michigan.

Abstract

As climate continues to change at a rapid rate, species are increasingly vulnerable to the resulting environmental changes. This is especially true for species whose fitness is closely linked to climate-associated environmental conditions. One of these vulnerable species is snowshoe hare, Lepus americanus, who depends on the timing and duration of snowfall to provide camouflage when they go through seasonal pelage changes from brown in the summer to white in the winter. Whereas snowshoe hare are stable across the core of their range, populations along the southern range edge are experiencing declines due to climate driven environmental changes that cause a mismatch between pelage color and the background environment (e.g., white hare pelage against a brown snowless background), making hare more conspicuous to predators, reducing survival and leading to localized extirpations. My thesis aimed to gather baseline demographic estimates (e.g., density) and to characterize fine-scale patterns of genetic diversity and gene flow of snowshoe hare subpopulations in a portion of their southern range within the Hiawatha National Forest-East (HNFE) in Michigan. I combined the two fields of demography and population genetics through non-invasive genetic tagging, in which snowshoe hare fecal pellets (n=847) representing 160 individuals were used in both spatially explicit capture-recapture and genetic analyses. Snowshoe hare density varied across occupied sites (range=0.02-0.838 hares/ha) and was low overall (>1 hare/ha), but similar to other areas along their southern range edge. Density was positively correlated with horizontal vegetation cover at 50 cm (p=0.007) and 100 cm (p=0.01), and conifer stem density (p