Department or Administrative Unit
The grouping behavior of the Chinese water deer (Hydropotes inermis) was studied at Poyang Lake National Nature Reserve, Jiangxi, China. I made three predictions to test the hypothesis that grouping is an anti-predatory strategy: (1) group size is negatively related to vegetation cover, (2) animals in groups have more time to feed than solitary animals, and (3) animals spend less time in vigilance when they are in groups than when they are alone. Results showed that group size was largest in the mating season and smallest in the parturition season. Deer tended to form larger groups when they were in short grass areas than in tall grass areas. Hence, the first prediction is supported. However, solitary deer and deer in groups did not differ in time allocated to feeding or vigilance. Therefore, predictions 2 and 3 are not supported. Time budget analysis revealed that females with young allocated less time to feeding, but more time to walking during the non-mating season. During the mating season, females grouped with males spent less time feeding than solitary females, and solitary males spent more time looking for females than did males grouped with females during the mating season. In light of the complications found in the grouping behavior of the water deer, the anti-predatory hypothesis seems to be insufficient as the only reason for the deer to group. Other socio-ecological factors are also important in determining the grouping behavior of this species.
Sun, L. (2002). Anti-predation does not fully explain grouping in the Chinese water deer (Hydropotes inermis). Acta Zoologica Sinica, 48(3), 201-10.
Acta Zoologica Sinica