By Nancy Shefferly
Geographic Range
The short-nosed fruit bat is found in Sri Lanka, India, South China, S.E. Asia, Western Malaysia, and Sumatra and neighboring small islands.
Habitat
Cynopterus sphinx is common in tropical forests and areas where fruit crops are cultivated. They can also be found in grassland and mangrove forests. They typically nest high in palm trees. The bats chew the fronds of the palms to constuct fairly simple tents. These bats are also known to construct tents by closely interweaving the leaves and twigs of creeping vines which cover buildings, but such nests are constructed only when palms are not available.
Terrestrial Biomes:
savanna or grassland
; forest
; rainforest
; scrub forest
.
Physical Description
These bats have a relatively long snout. Their upper parts are typically bright orange with paler underparts, but there is much variation. The fur is very fine and silky. The wing span of the adult is about 48 cm.
Some key physical features:
endothermic
; bilateral symmetry
.
Reproduction
In Central India, C. sphinx breeds twice per year. Females produce a single young at a time. The function of the female reproductive system is interesting in that each half of the bicornate uterus functions during alternate breeding cycles. The first pregancy cycle occurs from October through February/March. Mating occurs immediately postpartum, and a second offspring is born in July. Gestation 3-5 months. In 72% of bats, the first pregnancy occurs in the right horn of the uterus. The corpus luteum in the right ovary persists for some time after the pregancny and prevents ovulation from occuring in the right ovary during the second breeding cycle. This creats the pattern of alternate functioning of the two horns of the uterus. However, the corpus luteum in the left ovary does not persist until the beginning of the next breeding cycle. As yet, no reason has been found for the dominance of the right horn during the first breeding cycle.
Newborn bats weigh about 13.5 g and have a wingspan of 24 cm. By the time of weaning at 4 weeks of age, young bats weigh 25 g and have wings spanning 36 cm. Female short-nosed fruit bats reach sexual maturity at 5-6 months of age, but males are not capable of breeding until they are a year old.
Key reproductive features:
gonochoric/gonochoristic/dioecious (sexes separate); sexual
.
Behavior
The species is gregarious, and typically roots in same sex groups of 8-9 individuals. The sexes remain separate until the mating season, when group size increases. It is usual for 6-10 males and 10-15 females to share palm frond tents during the breeding season. Males stay with females for some time after mating, but later return to same sex groups. The adult sex ratio is very female biased. Researchers attribute this to the relatively rapid maturation of females compared to males.
Key behaviors:
motile
.
Food Habits
These bats are frugivorous, they and locate their preferred food items by scent. They have been described as voracious feeders, eating more than their body weight in food in one sitting. Some preferred fruits include ripe guava, banana, chikus (a popular Indian fruit crop), dates and liches.
Economic Importance for Humans: Negative
Short-nosed fruit bats inflict serious damage on many fruit crops, and are viewed by local people as a pest species. In addition, these bats are possible vectors for Japanese encephalitis, a very serious disease in humans.
Economic Importance for Humans: Positive
These bats are important dispersers of date palm seeds, and pollinate many night blooming flowers.
For More Information
Find Cynopterus sphinx information at
Contributors
Nancy Shefferly (author), Animal Diversity Web Staff.

