Picture recognition of food by sloth bears (Melursus ursinus).

Pictures are often used in cognitive research to represent objects and many species have demonstrated the ability to recognize two-dimensional pictures as representations of their three-dimensional counterparts. However, for ursids picture recognition has been reported in only one study of a single 11-year-old female American black bear (Johnson-Ulrich et al. 2016). We tested the picture recognition abilities of an additional species, the sloth bear. After a food preference test by which the bears' food options were ranked and categorized as high-, mid-, and low-preference items, we tested a sub-adult male and an adult female sloth bear by presenting two pictures of food in each testing trial-a high-preference food and a low-preference food. Both bears met the criterion by choosing the pictures of their preferred foods in at least 80% of the trials in three consecutive testing sessions. We then presented never-before-used pictures of high-preference versus low-preference food items and they again met our criterion.