Date of Award
Doctor of Philosophy
Woodrats (Neotoma spp.) are imperiled in the north-central and north eastern United States. In Illinois, eastern woodrats (N. floridana) experienced range reductions and population bottlenecks over the past century. Hypothesized reasons for the decline of many woodrat populations that inhabit rock outcrops in the eastern United States include parasitism by raccoon roundworms (Baylisascaris procyonis), hard mast shortages, owl predation, and reductions in crevice availability for nest construction. During 2004-2005, the isolated remnant populations along the Mississippi bluffs in southwestern Illinois were genetically augmented with 47 eastern woodrats from Arkansas and Missouri resulting in 40% admixture within the largest population. In 2009, a strong windstorm created canopy gaps and woody debris throughout this area, potentially improving habitat for eastern woodrats. During 2003–2009, 422 eastern woodrats were reintroduced to 5 sites in the southeastern Illinois, and 172 eastern woodrats to 2 southern Illinois state parks during 2013–2014. These reintroductions are the only woodrat reintroductions to date with >50 individuals released per site. Most previous woodrat reintroduction attempts have released small numbers of individuals (10–15 per site and 10–54 total) and either failed to establish populations or required frequent management for populations to persist. My objectives were to (1) investigate the status of augmented eastern woodrat populations in southwestern Illinois, (2) evaluate the success of the southern Illinois reintroductions, (3) investigate whether eastern woodrats demographics within a reintroduced metapopulation could be predicted by factors underlying hypothesized reasons for woodrat declines, and (4) develop and evaluate noninvasive alternatives to live-trapping and sign surveys for monitoring woodrat populations.
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