Dietary energy estimate inferred from fruit preferences of Cynopterus sphinx (Mammalia: Chiroptera: Pteropodidae) in a flight cage in tropical China

Abstract

From a conservation standpoint, inferences about dietary intake are much more robust when placed within a demographic, temporal and nutritional context. We investigated the dietary cornerstones of fruit preference and the dietary energy gained in the Short-nosed Fruit Bat Cynopterus sphinx. Feeding trials were conducted with 15 wild-caught bats kept in a large flight cage in Xishuangbanna, Yunnan, China, over nine weeks. The goal was to estimate the amount of food required for the sustenance of C. sphinx in captivity and calculate the food amount in terms of energy. Of the fruits (apple, banana, pear, papaya and guava) offered, apple (89%) and banana (93%) were found to be preferred. The relative consumption of fruit species tended to be positively correlated with the energy value per gram fruit. Banana (93%) was the most preferred and papaya (47%) the least preferred of the offered fruits. The results suggest that the minimum recommended dietary intake is 214-267 kJ per day for an individual of C. sphinx in captivity with conditions allowing flight. From this, we can assume that the same energy requirements may represent the minimum intake for bats in the wild. Both body mass and food consumption decreased significantly when bats were kept in a small cage.