Variations in reproduction and age structure in the North American river otter in North Carolina, USA

Historically, the North American river otter (Lontra canadensis; otter) was distributed across Carolina, USA, but populations were decimated by early 1900s. Otter trapping prohibited in 1938, reopened 1947, and gradually expanded until it opened statewide 2005. Between 1986 1992, Carolina Wildlife Resources Commission Great Smoky Mountains National Park released 404 otters to restore western Carolina. Our objective determine if age structure reproductive rates of throughout shifted from 1978 2018 between remnant reintroduced populations. During 1978–1980 (period 1; Coastal Plain) 2009–2013 2014–2016 2; statewide) seasons, we collected 1,439 carcasses licensed trappers, fur buyers, wildlife damage control agents 3 Furbearer Management Units (FMUs) 14 basins We conducted necropsies, used cementum annuli lower canine for analysis, counted corpora lutea fetuses fecundity estimates. Age distributions all skewed toward younger classes did not differ collection periods. period 1, adults Plain had higher counts than during 2, whereas yearlings juveniles numbers 2. differed among FMUs; Mountain FMU (x̄ = 2.56) 1.62) or Piedmont 1.91). Within pooling classes, increased 45% 1 Adult declined 16% while began reproducing periods, indicating that reproduction has 2018.