Sloth bear denning behavior in eastern Karnataka, India

Eastern Karnataka, India, has abundant sloth bear (Melursus ursinus) habitat made up of rocky scrub jungle and an abundance of naturally occurring caves, which the bears use for resting (day) and natal or neonatal dens. We deployed cameras on active dens from 2014 to 2018 and collected sloth bear resting and maternal denning behavior. We estimated a total of 37 different families with cubs aged 4 months to 2 years over the study, 15 with 1 cub, 19 with 2 cubs, and 3 with 3 cubs, for an average of 1.68 cubs/family. Data were analyzed from 34 dens being used by single bears and 21 dens being used by families. No significant differences were found between the temporal activity patterns of families and single bears entering (P = 0.145) or exiting (P = 0.649) dens. Nor were there any significant differences between the two groups seasonally. However, families entered dens significantly earlier during summer than they did during winter (P = 0.006), likely to escape the heat and earlier human activity. Individual resting and maternal dens were used sporadically. Resting dens were used for 1 (84.1%), 2 (11.6%), or >2 consecutive days (4.3%) before the bear left. Maternal dens were used for 1 (81.4%), 2 (3.9%), or >2 days (14.7%). Families with young cubs (3–9 months old) used dens for more consecutive days than did single bears or families with independently walking cubs. In 2 male cub family break-up events, the mother left the den that the two bears had been inhabiting together, and the young male continued to use the den. Notable interactions between bears at den sites were documented as were other species observed denning with or near sloth bears.