Evaluating Large-Scale Reintroductions of a Locally Imperiled Rodent

Although animal reintroductions are commonly used for conservation, documented successes with imperiled rodents are limited. Most Neotoma (woodrat) reintroduction attempts have released small numbers of individuals and either failed to establish populations or required frequent management for populations to persist. The translocation of 422 N. floridana (Eastern Woodrat) to 5 sites in the southeastern tip of Illinois during 2003-2009 and 172 Eastern Woodrats to 2 southern Illinois state parks during 2013-2014 are the only woodrat reintroductions to date with > 50 individuals released per site. We evaluated the success of these Illinois reintroductions by comparing Eastern Woodrat abundance and evidence of reproduction to published performance indicators. During 2012-2014, we captured 436 individual Eastern Woodrats and observed signs of reproduction in 63% of females from the southeastern tip of Illinois and captured Eastern Woodrats nearly 9 km from release sites. In 2017, we captured 52 Eastern Woodrats at Illinois state parks and observed signs of reproduction in 73% of females. Our findings indicate that the 2003-2009 Eastern Woodrat reintroduction and a 2013-2014 Eastern Woodrat reintroduction can be considered successful (all performance indicators met), while the other 2013-2014 Eastern Woodrat reintroduction can be considered potentially successful (1 out of 2 performance indicators met). Our study adds to the sparse information on successful rodent reintroductions that managers can use to inform structured decision making for future conservation and management actions.