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Dobsonia chapmani

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Taxonomy [top]

Kingdom Phylum Class Order Family
ANIMALIA CHORDATA MAMMALIA CHIROPTERA PTEROPODIDAE

Scientific Name: Dobsonia chapmani
Species Authority: Rabor, 1952
Common Name(s):
English Negros Naked-backed Fruit Bat, Philippine Bare-backed Fruit Bat

Assessment Information [top]

Red List Category & Criteria: Critically Endangered A2cd ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Heaney, L., Ong, P., Tabaranza, B., Rosell-Ambal, G., Balete, D., Alcala, E., Paguntulan, L.M., Pedregosa, S. & Cariño, A.B.
Reviewer(s): Hutson, A.M., Racey, P.A. (Chiroptera Red List Authority) & Stuart, S.N. (Global Mammal Assessment Team)
Justification:
D. chapmani is considered Critically Endangered, because a population decline of at least 80% over three generations (15-20 years) is inferred based on levels of hunting, habitat loss, fragmentation and degradation, all of which are ongoing. The species had previously not been recorded since 1964, despite intensive surveys and therefore (inaccurately) considered as Extinct (IUCN 2004). Extant populations were recently rediscovered on Cebu (2001) and Negros (2003).
History:
2006 Critically Endangered (IUCN 2006)
2006 Critically Endangered
1996 Extinct
1994 Extinct? (Groombridge 1994)
1990 Extinct? (IUCN 1990)
1988 Extinct? (IUCN Conservation Monitoring Centre 1988)

Geographic Range [top]

Range Description: The Negros Naked-backed Fruit Bat is endemic to the Philippines, where it is known only from Cebu and Negros Islands (Heaney et al. 1998; Simmons 2005) occurring at an elevation range from sea level to 860 m. It was thought to be probably extinct but was rediscovered at Carmen and Catmon on Cebu Island in 2001 (Pangutalan et al. 2004), and Calatong (near Sipalay City), Negros Occidental province, southwest Negros Island, in 2003 (Alcala et al. 2004). Further surveys might locate additional populations on both islands.
Countries:
Native:
Philippines
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Dobsonia chapmani was known to occur on the islands of Negros and Cebu between 1949 and 1964 and the species was believed to have become probably extinct by the 1970s as a result of forest destruction, disturbance through guano mining, and hunting (Heaney and Heideman 1987; Utzurrum 1992). About 35 specimens were collected in the late 1940s, 1950s and 1960s from several different cave systems in southern Negros some of which occurred in well forested and sparsely populated areas (Paguntalan et al. 2004). The species was reported to be formerly common in lowland forest from sea level to 800 m in southern Negros Island (Rabor 1986). Populations were rediscovered in Carmen and Catmon on Cebu Island in 2001 (Pangutalan et al. 2004), and five individuals were found in a small limestone forest fragment (Calatong) near Sipalay City, Negros Occidental province, southwest Negros Island in 2003 (Alcala et al. 2004).
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: D. chapmani occurs in remnant patches of secondary forest on karst limestone, where the natural vegetation is batino (Alstonia macrophylla), hindunganon (Macaranga sp.), tubug (Ficus septica) and matamban (Mallotus sp.) on steep slopes. The surrounding agricultural clearings are planted with abacca (Musa textiles), gabi (Colocasia esculenta) and coconuts (Cocos nucifera) (Paguntalan et al. 2004). The forest at Carmen and Catmon, Cebu island, is a critically important site for the species. However, the only available habitat for the species in this area is a series of small secondary-growth forest fragments on limestone, all of which are highly disturbed (Paguntalan et al. 2004).

The species lives in small caves or cracks in limestone, and forages in karst habitats, which have less rainfall than in other parts of the country. Records suggest that the species is exclusively a cave dweller (Rabor 1986; Heaney and Heideman 1987; Utzurrum 1992). However, three specimens were observed roosting in coconut fronds (Rabor 1954), indicating that D. chapmani is not restricted to forest and is able, to some extent, to make use of degraded and highly disturbed habitats (Paguntalan et al. 2004).
Systems: Terrestrial

Use and Trade [top]

Use and Trade: It is hunted for human food.

Threats [top]

Major Threat(s): The Negros Naked-backed Fruit Bat is threatened by habitat destruction and degradation, and harvest for meat throughout most of its range.

On Negros, lowland forest and karst habitat within the former known range of the species (before its rediscovery) have been heavily degraded by logging and clearing for agriculture. Since its rediscovery in 2001 there has been significant conversion of habitat to agriculture and mining for copper and gold within the current known range of the species on Cebu. Evans (1993) reported that less than 4% of Negros Island was forested, with small patches of degraded forest in the central and southern portion of the island. Roosts of the species are disturbed by guano miners. The largest remaining fragment of forest within the range of this species on Cebu is approximately 60 ha and this is threatened by the cutting of trees for charcoal and agricultural development (Paguntalan et al. 2004)

Harvest of D. chapmani for local consumption and sale has caused past population declines. Hunting is known to occur in the areas in which it has been rediscovered. In an ethnobiological survey, which included the islands of Sipalay City, out of 28 respondents, 15 reported hunting this species (A. Carino pers. comm. 2006). As a larger species, it is particularly targeted by hunters and in the past the species was sold in street markets. However, since 1995, D. chapmani has rarely been captured in caves where it has reportedly been hunted before. Interviews with hunters indicate that only about one or two individuals of D. chapmani have been taken during the 2003-2005 period indicating a population decline (Paguntalan in litt. 2006). It has been bred in captivity by collectors as a pet (L. Paguntalan pers. comm. 2006).

Conservation Actions [top]

Conservation Actions: On Cebu, D. chapmani occurs in the Catmon municipal watershed and it has been adopted as a flagship species by the local government in Carmen municipality. There are political problems in the region and researchers are reluctant to take part in surveys there.

The local government of Carmen has organized a group of environment protection coordinators who patrol and report violations to the municipal mayor and council. Part of the duty of the environment protection coordinators is to survey cave sanctuaries and report illegalities e.g. tree felling and hunting particularly of bats. The municipal government has declared the caves where these bats occur as Naked-backed Fruit Bat Sanctuaries. Reforestation project is underway there (Paguntalan in litt. 2006).

The largest remaining forest fragment is not within a protected area and was not included in the listing of Key
Conservation Sites in Cebu (Mallari et al. 2001). This needs to be rectified.

On Negros, the species has been recorded from a provincial level forest reserve in the southwest of the Island (Calatong). Two towns are pending resolutions to adopt this as a flagship species.

There is an urgent need for improved protection of the remaining known populations on both islands, and further surveys are needed to locate additional populations.

Bibliography [top]

Alcala, E. L., Paalan, R. B., Averia, L. T. and Alcala, A. C. 2004. Rediscovery of the Philippine bare-backed bat (Dobsonia chapmani Rabor) in southwestern Negros Island, Philippines. Silliman Journal 45: 123–136.

Evans, T. D. , Dutson, G. C. L. and Brooks, T. M. 1993. Cambridge Philippines Rainforest Project 1991 Final Report. BirdLife International, Cambridge, UK.

Fauna and Flora International. 2001. 'Extinct' Philippine naked-backed fruit bat rediscovered on Cebu. Fauna and Flora 1: 12 pp.

Heaney, L. R. and Heideman, P. D. 1987. Philippine fruit bats, endangered and extinct. Bats 5: 3-5.

Heaney, L.R., Balete, D.S., Dollar, M.L., Alcala, A.C., Dans, A.T.L., Gonzales, P.C., Ingle, N. R., Lepiten, M. V., Oliver, W. L. R., Ong, P. S., Rickart, E.A., Tabaranza Jr., B.R. and Utzurrum, R.C.B. 1998. A synopsis of the Mammalian Fauna of the Philippine Islands. Fieldiana: Zoology 88: 1-61.

Mallari, N. D., Tabaranza Jr., B. R. and Crosby, M. 2001. Key Conservation Sites in the Philippines. Department of Environment and Natural Resources Philippines and Bookmark Publishing, Inc., Makati City, Philippines.

Mickleburgh, S. P., Hutson, A. M. and Racey, P. A. 1992. Old World Fruit-Bats - An Action Plan for their Conservation. IUCN, Gland, Switzerland.

Paguntalan, L.-M. J., Pedregosa M. G. and Gadiana, M. J. C. 2004. The Philippine Bare-Backed Fruit Bat Dobsonia chapmani Rabor, 1952: Rediscovery and Conservation Status on Cebu Island. Silliman Journal 45(2).

Rabor, D.S. 1986. Guide to the Philippine flora and fauna. Natural Resources Management Centre. Ministry of Natural Resources and University of the Philippines.

Simmons, N. B. 2005. Order Chiroptera. In: D. E. Wilson and D. M. Reeder (eds), Mammal Species of the World, pp. 312-529. The Johns Hopkins University Press, Baltimore, MD, USA.

Utzurrum, R. C. B. 1992. Conservation status of Philippine fruit bats (Pteropodidae). Silliman Journal 36: 27-45.


Citation: Heaney, L., Ong, P., Tabaranza, B., Rosell-Ambal, G., Balete, D., Alcala, E., Paguntulan, L.M., Pedregosa, S. & Cariño, A.B. 2008. Dobsonia chapmani. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 24 November 2014.
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