Vertebrates (pdf)

	Bats in an underground water channel
	Diadema sea urchins and the Black-spot tuskfish
	More new fishes from the Cape d'Aguilar Marine Reserve

Bats in an underground water channel

by Sze-man Cheung

Bats were sighted during an exploration to an underground water channel in the northern New Territories in December 2002 by Dr. Benny Chan, Rita Yam and the author (see Porcupine! 27 p. 18-19). After examination of some close-up photos, some of the bats were identified as Bi-colored round-leaf bat (Hipposideros pomona).

The bodies of the bats ranged from 4 to 6 cm and had a brownish yellow coat and grey belly. The presence of a pink non-pointed leaf nose and disproportionately large ears distinguished them from the Great round-leaf bat (Hipposideros armiger) (Ades, 1990; Ades et al., 2002). The bats roosted in a dark humid underground water channel which is a part of a water network conducting hill stream water to Plover Cove Reservoir. Water channels are typical preferred habitat of H. pomona (Ades, 1994, 1999; Ades et al., 2002). They are used as roost sites by many bat species in Hong Kong (Ades, 1999). Although H. pomona is insectivorous (Ades, 1990, 1994, 1999; Ades et al., 2002), it is unknown whether the moth fragments and dead ‘headless’ fish found within the channel (see Porcupine! 27 p. 18-19) were food remains of the bats.

Previous studies had shown that H. pomona is a species with a moderate colony size of up to 1000 individuals (Ades, 1994, 1999; Lin & Chen, 2002). We observed over 200 bats in approximately 300 m of the channel well within the range of a normal colony size for H. pomona.

Disturbance to the bat colony is one of the major threats to bats in Hong Kong, in addition to filling of tunnels and habitat destruction (Ades, 1990). It should be stressed that all bats are protected locally under Wild Animals Protection Ordinance, Cap. 170. No person can collect any bat unless under a special permit obtained from the Agriculture, Fisheries and Conservation Department.

Bibliography

Ades, G.W.J. (1990). Bats of Hong Kong. World Wide Fund for Nature (HK). 40 pp.

Ades, G.W.J. (1994). A comparative ecological study of insectivorous bats (Hipposideridae, Vespertilionidae and Rhinolophidae) in Hong Kong, with special reference to dietary seasonality. Ph.D. Thesis, Department of Ecology & Biodiversity, The University of Hong Kong. 279 pp.

Ades, G.W.J. (1999). The species composition, distribution and population size of Hong Kong bats. Memoirs of the Hong Kong Natural History Society 22: 183-209.

Ades, G.W.J., Lau, M.W.N. & Crow, P.A. (2002). Mammals of Tai Po Kau Nature Reserve. Friends of the Country Parks & Cosmos Books Ltd., Hong Kong. 40 pp.

Lin, L.K. & Chen, J.H. (2002). Species richness and abundance of cave bats in Hong Kong. In: The 2nd Conference on the Status and Conservation of Hong Kong’s Wild Animals and Plants (ed Wildlife Conservation Society), pp. 23-29, Wildlife Conservation Society, Hong Kong. (in Chinese)