جستجوگری فعالیت و انتخاب مواد غذایی در توله خرس سیاه و سفید یتیم آسیایی در غیاب یادگیری اجتماعی از یک مادر

In different groups of mammals the role of social learning in ontogeny of foraging behaviour is variable. Normally developed foraging skills are necessary for the survival of orphaned cubs, released into the wild after rehabilitation. The development of foraging behaviour in Asiatic black bears (Ursus thibetanus) has been poorly studied, and the role of learning from the mother remains undefined. Here we investigated the ontogeny of three aspects of foraging behaviour (foraging activity, diet composition and food selection) and compared our observations with literature data on wild adult bears. Two observers (including the author) reared three orphaned Asiatic black bear cubs from the age of three to 20 months in a natural environment in the Far East of Russia. We performed ad libitum observations of the cubs’ foraging behaviour during daily excursions in the forest, totaling 2000 h of visual observations. The crop of trees and shrubs was estimated visually in grades (0–5) every 10 days. We found that the seasonal dynamics of the cubs’ foraging activity correlated with food abundance and their nutritional requirements, allowing fattening for winter survival. The diet composition of the orphaned cubs was species-specific, close to that of wild conspecifics, although showing age-related and geographical specificity. The cubs assessed the edibility of foods via taste and olfaction analyzers, trying various food items and selecting those consumed by wild bears. We conclude that in the ontogeny of Asiatic black bear foraging behaviour, the seasonal dynamics of diet composition and foraging activity are based on inborn mechanisms, while food preferences develop through trial and error, i.e. individual learning. Therefore, we discovered that Asiatic black bear orphaned cubs, grown in a natural environment under the limited care of two observers and with supplemental feeding, are able to learn feeding on natural foods from the age of five months.