Mating and First-season Births in Interstate 



Transplanted River Otters, Lutra canadensis 



(Carnivora: Mustelidae) 



Peter J. Tango and Edwin D. Michael 



Division of Forestry, West Virginia University 



Morgantown, West Virginia 26506 



And 



Jack I. Cromer 



West Virginia Department of Natural Resources 



Elkins, West Virginia 26541 



ABSTRACT. — River otters were transplanted from North Carolina 

 and Maryland into the West Fork River, W. Va., during February and 

 April 1987. Birth of young and mating by the released otters occurred 

 within 2 months of release. This represents the only known occurrence 

 of birth during the same year following transplanting. 



Several states have transplanted river otters (Lutra canadensis) 

 (Schreber) in recent years in an attempt to establish or reestablish 

 breeding populations. Birth of young during the same year otters were 

 released was not documented in any of those states. Releases in Missouri 

 resulted in reproduction during the second post-release reproductive 

 period (Erickson and McCullough 1987). Timing of confinement in 

 Louisiana, the source of the otters, and of subsequent release in 

 Missouri appeared to be the cause of that reproductive delay (Erickson 

 and McCullough 1987). Female otters transplanted by one Louisiana 

 supplier were usually held until after parturition (Serfass and Rymon 

 1985). In Tennessee, no reproduction was documented during the first 

 (17-month) post-release period of radio-tagged animals into the Obed 

 River system (Griess and Anderson 1987). One of 1 1 females transplant- 

 ed to Pine Creek, northcentral Pennsylvania, and thought to be pregnant 

 when released in August, reportedly remained near a den the next 

 spring; area residents indicated a family of otters was present in that 

 stretch of river that year (Serfass and Rymon 1985). Pollard (1984) in 

 Oklahoma also did not indicate any first-year post-release reproduction. 



In 1986, a program for reintroduction of river otters into northcen- 

 tral West Virginia was initiated. The first release of four radio-tagged 

 otters (three males and one female) on the West Fork River was on 5 



Brimleyana 17:53-55, December 1991 53 



