Reproductive performance of otters Lutra lutra (Linnaeus, 1758) in Eastern Germany: low reproduction in a long-term strategy

The reproductive status of female otters ( Lutra lutra ) was determined from an examination of 518 carcasses collected from Eastern Germany between 1950 and 2001. In Germany otters mate throughout the year. Significant seasonal differences are evident with a distinct peak in summer. Females were in breeding condition between the ages of three and 15 years, with the majority between six and nine years. The mean litter size at birth was 2.36, which was the lowest when compared with other inland populations. There were no significant differences in litter size for regions, seasons or age. Prenatal losses account for 26.31%. The mortality between birth and first appearance of cubs following their mother is about 29%. An effective reproduction rate of 78.4% was deduced from the known age structure of the sample and the proportion of breeding females. Reproductively active females show a significantly higher body condition than non-reproductive females. Following these investigations into breeding status, suggestions on reproductive output and the life history of the otter are discussed.  © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 77 , 329–340.