Development of a noninvasive photograph-based method for the evaluation of body condition in free-ranging brown bears.

摘要: Body condition is an important determinant of health, and its evaluation has practical applications for the conservation management mammals. We developed a noninvasive method that uses photographs to assess body free-ranging brown bears (Ursus arctos) in Shiretoko Peninsula, Hokkaido, Japan. First, we weighed measured 476 captured during 1998-2017 calculated their index (BCI) based on residuals from regression mass against length. BCI showed seasonal changes was lower spring summer than autumn. The torso height:body length ratio strongly correlated with BCI, which suggests it can be used as indicator condition. Second, examined precision photograph-based measurements using identifiable bear Rusha area, special wildlife protection area peninsula. A total 220 lateral this were taken September 24-26, 2017, classified according posture. height:body/torso four measurement methods compared among postures photographs. results height:horizontal (TH:HTL) could applied most diverse postures, coefficient variation <5%. In addition, when analyzing June October 2016-2018, TH:HTL significantly higher autumn spring/summer, indicates reflects wild bears. Third, actual seven females same individuals. found significant positive relationship between estimated high accuracy Our simple accurate useful monitoring repeatedly over years contributes further investigation relationships condition, food habits, reproductive success.