Dobsonia chapmani

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

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 Assessed:

2008

Assessor/s

Heaney, L., Ong, P., Tabaranza, B., Rosell-Ambal, G., Balete, D., Alcala, E., Paguntulan, L.M., Pedregosa, S. & Cariño, A.B.

Evaluator/s:

Huitson, A., 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)
1996	–	Extinct (Baillie and Groombridge 1996)
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 map to view full version)

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

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 lower rainfall than in other parts of 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

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 lower rainfall than in other parts of 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

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).

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.

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.

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. In: IUCN 2008. 2008 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 23 November 2008.
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