Abstract
into existence in the 19th century. Nevertheless, scientifically based knowledge on bear nutrition in terms of nutritional composition of natural food, digestion and requirements for growth, maintenance and reproduction are rare. The diet for different bear species in captivity ? with the exception of polar bears, sloth bears and giant pandas ? is often still very similar, consisting of fruits, mainly apples and pears, and vegetables, mainly carrots, to varying degrees supplemented by animal matters of different origin. This composition is based on the assumption of an omnivorous feeding style without considering species differences in terms of food composition and seasonal (and hormonally triggered) fluctuations in food intake. In consequence, nutrient composition and amounts of captive diets can differ significantly from what can be expected in the wild. In tropical bears, this feeding practice often results in obese bears, whereas bears of the moderate and higher altitudes are too lean during certain seasons. The feeding technique ? one main meal with or without several scatter feeds per day offered in similar quantities over the whole year - does apply more to a tropical carnivore than to an omnivorous carnivore with a simple digestive tract, but behavioural and physiological adaptations to survive on a mainly vegetarian diet in different climates. This technique is one of the causes for the development of stereotypic behaviours, which are frequently observed in ursids. The few scientific studies on ursid nutrition focus on digestion of the omnivorous brown bears and American black bears and the carnivorous polar bears. Similar studies are lacking for the other more tropical species with somewhat different food niches and specializations either towards more vegetarian (Andean bears) or more insectivorous diets (sun bear and sloth bear). The rapidly growing knowledge on feeding ecology of all ursid species in combination with their morphological features will be used to propose diets and feeding techniques which approach the species specific behavioural and nutritional requirements more closely. Examples of diets and feeding techniques will be provided for brown bears, polar bears, Andean and sun bears. Finally fields for research on bear feeding and nutrition will be briefly outlined.