Reintroduction of the European mink Mustela lutreola in Saarland, Germany. Preliminary data on the use of space and activity as revealed by radio-tracking and live-trapping

As an attempt to help conserve the endangered European mink Mustela lutreola (Linnaeus, 1761), a reintroduction program was started in a nature reserve in Saarland, Germany; the present study is part of this ongoing reintroduction project. Within the first 2 yr period, 48 (16 m, 32 f) founder animals were reintroduced, out of a total of about 75 animals intended for release in the course of the 3 yr project. Prior to reintroduction, the animals were acclimatized using soft-release pens where they were preconditioned with natural prey . A number of individuals (n = 18) were set free in groups of mating partners (ffm, fm) and in mother-offspring groups. Thirty-three European mink (14 m, 19 f) were fitted with intraperitonial transmitters and radio-tracked and surveyed via live-trapping. Animals were monitored from April 2006 to May 2008 to determine the distribution, size and temporal changes in home range. Released animals showed linear home ranges spreading along rivers and brooks. Home range sizes were 7.2 km (88 ha) for 1 adult male, 0.2-5.9 km (1-505 ha) for adult females, around 1.7-5.6 km (17-132 ha) for juvenile males and 9.2 km (778 ha) for 1 juvenile female, respectively. The released adults showed inter-, but only few intra-, sexual home range overlaps. In contrast, juveniles did not show any home range overlaps. In winter, home range size decreased to a minimum of about 1 km. Further, home range size for females decreased around parturition but increased successively at time of weaning. The activity pattern of released animals was highest at night (especially around dusk and dawn).