ИСТИНА

The goal of our project is to study behavioral ontogenesis of Asiatic Black bear orphaned cubs during their preparation for independent life in natural environment. The work was started in March 2009 in the Russian Far East (western slopes of the Sikhote-Alin Mountains). 3 cubs (♂♂♀), orphaned at the age of 2,5 months after den hunt, are under observation. We use methods of rearing, invented and successfully practiced for 3 decades by Dr V. Pazhetnov for brown bear orphaned cubs’ rehabilitation in European Russia. This research is realized due to an interfamilial bond between bears and humans based on the imprinting – retaining smell and appearance of the mother. It happens in a short sensitive period, while bear family emerges from the den in spring. Cubs are reared by two persons only, who surrogate a mother, with minimal custodial contact. Interactions with other humans are forbidden. We conduct regular excursions in the forest along selected routes, while cubs follow us due to imprinting. Cubs overnight in the forest enclosure, where they receive supplementary feeding. We don’t teach them anything. Basic foraging, defensive and social skills are stereotypic and instinctive and develop in certain age, identical to those of wild cubs living with a mother. Bear cubs are mostly vegetarians. In May they begin eating leaves and flowers of grasses, shrubs and trees. In early summer, when their teeth get stronger, cubs feed on roughage, such as stalks of umbelliferous plants. Great part of their summer diet is composed by eggs, nymphs and honeycombs of insects. Since August and until denning cubs consume mostly fruits of trees and shrubs. Taking more caloric food and intensification of nutrition is associated with fat accumulation, necessary for survival in winter. As well as adult bears, cubs build feeding nests on trees (Padus maacki, Quercus mongolica) and begin eating some fruits in the leafage before they mellow and fall. In 2009 poor yield of oak and cedar stimulated cubs to use alternative foods. Defensive behavior is connected with tree climbing, what they learn to do in April. Basic defensive reactions are formed by age of 7 months and are associated with the presence of large carnivores (tiger, adult brown and Asiatic black bears). Cubs encountered wild Asiatic black bears and their signs and tracks regularly. Degree of phobic reaction correlates with age and sex of encountered bear and the freshness of its tracks. In June we observed pronounced phobic reaction of cubs towards adult males. This time bears mate, and adult males are extremely aggressive to everyone, including bear cubs. In August the intensity of fear decreases. Decline of intraspecific aggression contributes to better exploring of food sources in places of local food concentration where bear density is high. Defensive behavior always interrupts foraging and play behavior and is usually gradually replaced by investigating behavior. In 2009 our research will be ended when cubs den up independently in October-November. Prior to denning they will be immobilized, ear-tagged, measured, weighted and sampled. Data on behavioral ontogenesis of Asiatic black bear are fragmentary. That’s why previous attempts of orphaned cubs’ rehabilitation usually were inadequate to biological features of that species. Alike experiment, when cubs and humans form a surrogate family, is the first ever done. Fast following reaction of cubs allowed us to investigate their behavior particularly and continuously in various natural situations. Annually in Russia only official statistics registers 30-40 Asiatic black bear orphans, which are lost from the population. Nowadays all attempts of cubs’ rehabilitation and release are desisted. We hope that achieved data will contribute to safe returning of cubs back to the wild.