Unassisted weighting of European bison

Abstract

Since the summer of 2018, six European bison (Bison bonasus) born in 2016, graz over an area of 12 ha at Nordens Ark on the west coast of Sweden, where E. bison used to occur during the early Holocene. In order to collect their weight in a stress free manner on a regular basis, an unassisted weighting station was designed and constructed. After a 53-day period of habituation, animals calmly entered the scale when passing between enclosures. Some of those individuals tended to be repeatedly startled as changes were made in the setup. A wide fence opening and covering of the platform floor with naturally occurring soil and faeces seemed to encourage a calm passage. When entering the scale, the weight and identity of the animal was recorded by a trail camera triggered by the movement. Weights have continuously been recorded since October 2018. A knowledge of the body mass of particular individuals provides an information regarding their physiological status and is important for proper management. According to obtained results the body mass of E. bison at Nordens Ark exceeds that of free-living E. bison of similar age, from Białowieska Forest.