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	Feral / stray dogs and civet mortality on Kau Sai Chau, 2001-2
	Sightings of 'overseas' colour-ringed Black-faced Spoonbills in Hong Kong
	Pipistrelles use bat roost boxes on Kau Sai Chau

Feral/stray dogs and civet mortality on Kau Sai Chau, 2001-2

by Thomas D. Dahmer
Ecosystems Ltd., 2/F Kingsun Computer Bldg., 40 Shek Pai Wan Road, Aberdeen, Hong Kong, ecosys@pacific.net.hk

Introduction

Mortality of Small Indian (Viverricula indica) and Masked Palm (Paguma larvata) Civets between May 1998 and May 2001 on Kau Sai Chau was documented by Dahmer (2001). Five dead Small Indian Civets and one dead Masked Palm Civet were reported on a ±6 km² island in Port Shelter of eastern Hong Kong. The cause of death in each case was determined to be attack by feral/stray dogs (Canis lupus familiaris). Between June 2001 and November 2002 six additional Small Indian Civet fatalities were recovered from Kau Sai Chau, raising the total to 12 civets over a period of four years and eight months. The cause of death in each of the latter cases was also determined to be attack by feral/stray dogs. Based upon recovered carcasses the rate of civet mortality due to dog attack on Kau Sai Chau has averaged one civet every 4-5 months since May 1998. Most of the attacked civets were sub-adult males that appeared to be dispersing from litters.

Many feral/stray dogs were removed from Kau Sai Chau between 1998 and 2002, but the population was seldom, if ever, reduced to zero for more than a few weeks at a time. At almost all times the island was occupied by >2 feral/stray dogs.

The purpose of this manuscript is to document the frequency of dog attacks on Small Indian Civets in a situation that is uniquely suited to monitoring this relationship. It is hoped that this report will encourage a more aggressive feral/stray dog removal and control programme in Hong Kong in the interests of reducing civet mortality. One additional Small Indian Civet fatality is included in this report to document a death caused by vehicle collision.

Methods

Methods reported in Dahmer (2000) were used in the 18-month follow-on period from June 2001 through November 2002. All dead civets were reported by the golf course greenskeeping staff. One vehicle-killed Small Indian Civet was recovered by the author from Clearwater Bay Road on 4 July 2001. Nomenclature used in this report follows Wilson and Reeder (1992).

Results

Over a period of 18 months from June 2001 through November 2002, six dead Small Indian Civets were recovered from northern Kau Sai Chau. These are listed in Table 1 together with the fatalities reported in Dahmer (2001). All fatalities were discovered shortly after sunrise when the greenskeeping staff spread out over the golf courses to mow grass and tend to facilities. Only the two March 2002 fatalities were inspected in detail prior to disposal of the carcasses. No flesh or internal organs of the two inspected civets had been eaten, and none of the body cavities had been opened (except by tooth punctures through skin and underlying flesh).

Table 1. Civet fatalities documented on Kau Sai Chau between May 1998 and November 2002.

Similar to the fatalities reported in 1998-2001, those during 2001-2 were on the golf fairways and practice areas. The civet recovered on 4 March 2002 had suffered numerous bites to the dorsal lumbar region. The bites penetrated the skin and flesh to the spine and pelvis. The civet recovered on 6 March 2002 had suffered one bite on the left thorax that penetrated the rib cage, and one bite on the right groin that penetrated the abdominal cavity. The locations of recovery of both civet carcasses are areas frequented by feral/stray dogs at night. Weights and measurements of the two civets recovered in March 2002 are listed in Table 2 together with those of a vehicle-killed Small Indian Civet recovered from Clearwater Bay Road on 4 July 2001. The latter fatality is not discussed further in this report.

Table 2. Sex, age class, and morphometrics of one vehicle- killed civet recovered from Clearwater Bay Road and two dog-killed civet carcasses recovered on Kau Sai Chau.

*This record is included in this report for the purpose of documentation only.

Discussion

For several reasons Kau Sai Chau is a unique situation in which to monitor the frequency of dog attacks on civets. Firstly, dogs do not appear to eat the civets they kill or remove the civet carcasses to remote locations where discovery would be unlikely. Dogs do not eat civets possibly because the dogs are often fed by visitors to the island or part-time owners living or working on the island. Secondly, dead civets are readily visible on the short-grass fairways of the golf courses at Kau Sai Chau. Thirdly, the golf courses are closely inspected at sunrise every day of the year by the greenskeeping staff who cover the entire course maintaining turfgrass and tending to facilities. This combination of highly visible evidence and intensive monitoring at a consistent level of effort means that any civet killed on the golf course is likely to be seen.

Two of the six recovered carcasses were examined and both bore bite wounds that penetrated thoracic or abdominal body cavities and caused blood loss. These results are similar to the results reported earlier of six civet fatalities attributable to dog attacks over 37 months (Dahmer 2001). The 2001-2 mortality rate due to dog attack averaged one kill every three months compared to a rate approximately half that in 1998-2001 (one kill every 6 months). The two time periods combined yield a rate of one kill every 4.7 months. This might be a minimum estimate of the rate of civet mortality attributable to dog attack because some attacks may take place outside the golf course where they would go undetected. The population biology of Small Indian Civets on Kau Sai Chau has not been studied, so it is not possible to calculate the population impacts of the estimated loss to dog attack of 2.6 civets per year. However, because the portion of the island occupied by the golf course is approximately 2.2 km², the rate of civet mortality due to dog attack can be estimated as 1.2 deaths/km²/year. If this rate of mortality is applied to the Small Indian Civet’s estimated range throughout Hong Kong (estimated from Suen Kai-yuen 2002:264-265 at >200 km²), the annual losses could well exceed 240 civets.

As in the earlier report other possible agents of civet mortality at Kau Sai Chau could be shuttle buses, other civets, or Eagle Owls (Bubo bubo). Buses are again ruled out because the recovered carcasses were found distant from roads, examined carcasses showed no sign or trauma suggestive of vehicle collision, and there was little overlap between shuttle bus operating schedules (diurnal) and civet activity patterns (nocturnal). Other civets were ruled out because there is no indication that civet density is so high that intra-specific aggression over territories or mates could lead to civets killing civets. Further, there is no indication in the literature that intraspecific agression is an agent of civet mortality. Eagle Owls were ruled out because of the location and type of wounds, and because civet carcasses were not fed upon. Finally, attack by dogs was strongly suggested by the pattern of bites to the lower back, hind legs, and groin, that is characteristic of the canid attack strategy (Brown undated).

Predation on civets in Hong Kong is only one of the many reasons for eliminating feral/stray dogs from the countryside. Other researchers have suggested that Indian Muntjac (Muntiacus muntjak) may be attacked by feral/stray dogs (Pei Jai-Chyi et al. 2002, Suen Kai-yuen 2002). Given that there are no other extant mammals that prey on Indian Muntjac in Hong Kong and that Muntjacs are neither abundant nor is their local population irruptive (as are other deer populations in the absence of canid and felid predators), the hypothesis that feral/stray dogs limit population numbers of Muntjacs is credible. Thus conservation of Indian Muntjac is a second justification for eliminating feral/stray dogs. Public sanitation and human health and safety are additional good reasons for eliminating feral/stray dogs from Hong Kong’s wild lands (see Dahmer et al. 2000).

Acknowledgements

Civet carcasses and other wildlife observations were often reported by personnel at The Jockey Club Kau Sai Chau Public Golf Course Ltd. Their cooperation and assistance are greatly appreciated. Studies reported here were funded by The Jockey Club Kau Sai Chau Public Golf Course Ltd., whose support is gratefully acknowledged. AFCD assisted frequently in capture of feral/stray dogs on Kau Sai Chau.

Bibliography

Brown, D.E. (undated). The wolf in the southwest: The making of an endangered species. Univ. Arizona Press, Tuscon, 195p.

Dahmer, T.D. (2001). Feral dogs and civet mortality on Kau Sai Chau, Sai Kung, Hong Kong. Porcupine! 24: 16-18.

Dahmer, T., Coman, B. & Robinson, J. (2000). Ecology, behaviour and persistence of packs of stray/feral dogs with implications and practical recommendations for control. Final report. Dept. Agriculture, Fisheries & Conservation, Government of Hong Kong Special Administrative Region, 10 March 2000, 30pp +app.

Pei, J.C., Lai, Y.C. & Suen, K.Y. (2002). Present status of larger mammals in Hong Kong’s country parks and their conservation concerns. Wildlife Conservation Foundation Workshop, October 2002, Hong Kong. Wildlife Conservation Foundation Ltd., Chai Wan, Hong Kong.

Sue, K.Y. (2002). Lost Mammals. Guo Liang Hui Xin Shiye Co. Ltd., Hong Kong.

Wilson, D.E. & Reeder, D.M. (eds.). (1992). Mammal species of the world: a taxonomic and geographic reference. 2^nd ed. Smithsonian Institution Press, Washington, D.C. 1206pp.