Scent marking in Eurasian beaver Castor fiber during winter

The Eurasian beaver Castor fiber Linnaeus, 1758 deposit castor fluid (casto reum) and/or anal gland secretion at scent mounds in their territory year r ound. We investigated the hypothesis that during winter Eurasian beavers ma y intensify use of scent, in year round ice-free water systems, during the breeding season. This study showed that the median number of scent marks in 7 territories increased significantly in the breeding (January-March 1996) , compared to the nonbreeding portion of winter (October-December 1995), wh ich is consistent with our prediction. The median number of scent marks was significantly higher during February, compared to January and March. This may be due to females approaching or being in oestrous in our study area du ring February. Further studies are, however, needed to clarify how informat ion in scent marks are coded and transmitted during the breeding season.