Body mass and physical changes of reintroduced Asiatic black bears

The information on animal weight is often an essential component of wildlife management and research. However, it may be difficult to obtain direct scale weights from the free-ranging large animals when equipment needed to weigh the animals are inadequate or unavailable. In these cases, body weight can be estimated by morphometric equation. We investigated body mass and size (16 body parts) of reintroduced Asiatic black bears (Ursus thibetanus; ABB) and their offsprings (28 males and 24 females, age 7 months − 12 years) between 2005 and 2013. Mean body weight of adult females and males in September − December were 132.2 ± 11.8 and 166.6 ± 7.2 kg, respectively, which was higher than those in April − August (103.8 ± 5.6 and 141.7 ± 6.3 kg, respectively). We developed three predictive equations for body mass by pad width and season that can utilize the footprint size before capturing. In addition, we also developed eleven multiple regression models to predict body mass through body part measurements after capturing, and selected two best models including neck girth, chest girth, body length, season, and sex. This study is the first to develop predictive equations for body mass by simple measurements of body parts in ABB. This data will not only help to understand the relationship between the weight and body size of reintroduced bears, but by estimating the weight without a scale, it will help to make the task easier and faster and to determine the appropriate anesthetic dose in the field.