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

Aeshita Mukherjee,Burkhard Wilske,Jin Chen

doi:10.11609/jott.o2326.908-18

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.

Highlights

Fruit bats play a crucial role in maintaining diversity in plant communities via regeneration and genetic flow of dominant forest trees (Banack 1996, 1998)
Large differences existed in the consumption relative to fruit species
Neither guava nor pear was consumed in the same amounts, and papaya was the least preferred of the fruits

Summary

Introduction

Fruit bats play a crucial role in maintaining diversity in plant communities via regeneration and genetic flow of dominant forest trees (Banack 1996, 1998). Food resources like flowering and fruiting plants exert different selective forces on the foraging behaviour and energetic budgets of pollinators and the seed dispersers (Voigt et al 2006). A number of different physiological and behavioural strategies have been identified in mammals helping them to accommodate increased energy demands at various stages of their life cycle. These strategies include increases in energy intake (Brody 1945; Randolph et al 1977; Millar 1978; Hickling et al 1991) or mobilization of fat reserves to fuel the increased demands (Fedak & Anderson 1982). It has been shown that lactating bats Myotis lucifugus and Eptesicus fuscus) and fruit-eating megachiropteran Rousettus aegyptiacus increases their field metabolic rate (Korine et al 2004; Kurta et al 1989a)

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