Dobsonia chapmani, Rabor, 1952

Don E. Wilson & Russell A. Mittermeier, 2019, Pteropodidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 16-162 : 110

87.

Philippine Naked-backed Fruit Bat

Dobsonia chapmani

French: Roussette de Chapman / German: Chapman-Nacktriickenflughund / Spanish: Dobsonia de Chapman

Other common names: Negros Naked-backed Fruit Bat, Philippine Bare-backed Fruit Bat

Taxonomy. Dobsonia chapmani Rabor, 1952 ,

Pagyabonan, Bais, Negros Island, Philippines.

This species is monotypic.

Distribution. Endemic to the Philippines, where it is known only from Cebu and Negros Is.

Descriptive notes. Tail 23-26 mm, ear 15- 27 mm, hindfoot 36-39 mm, forearm 123— 131 mm; weight 138-143 g. On specimens from Negros, dorsal fur is rich brown to umber on head, mantle, and face. Fur along forearm is golden tawny olive. Ventrally, throat is raw umber, center of breast is olive-brown (this distinct breast color is not present in some specimens), and sides of breast and belly are drab. Specimens from Cebu have been described only as “generally colored olive-green.” Wings join along spinal region with underlying fur. Flight membranes are black. Index claw (second digit of wing) is absent. Short tail is free of narrow uropatagium that runs along legs to short stiff calcars. Large eyes reflect reddish eyeshine. Premaxillae and canines are proclivous.

Habitat. Historically tropical, moist, dipterocarp forests from sea level up to elevations of 860 m. Currently, Philippine Naked-backed Fruit Bats occur in only a few remnant patches of secondary forest on karst limestone where natural but highly disturbed vegetation is principally composed of Alstonia macrophylla (Apocynaceae) , Macaranga sp. (Euphorbiaceae) , Ficus septica ( Moraceae ), and Mallotus sp. (Euphorbiaceae) growing on steep slopes not used by agriculture. They will forage in highly disturbed agricultural areas.

Food and Feeding. The Philippine Naked-backed Fruit Bat is frugivorous. It forages on canopy fruits, almost certain to include native figs. Mist-net captures found it flying up to 6 m aboveground.

Breeding. A female Philippine Naked-backed Fruit Bat was observed at night landing on a coconut frond while carrying her small young in December. Longevity is 5-7 years In captivity.

Activity patterns. The Philippine Naked-backed Fruit Bat is nocturnal. It roosts in small caves or cracks in limestone and forages in karst habitats. Although principally a cavedweller, three specimens were observed roosting in coconut fronds, and thus it is not restricted to forests and is able, to some extent, to use degraded and highly disturbed habitats.

Movements, Home range and Social organization. The Philippine Naked-backed Fruit Bat is gregarious and roosts hanging from cave ceilings or walls clumped together in groups of up to 30 individuals; maximum colony size in a cave was estimated at 300 individuals in the late 1940s. Philippine Naked-backed Fruit Bats have also been observed in groups of 2-3 individuals, roosting among fronds of coconut palms.

Status and Conservation. Classified as Critically Endangered on The IUCN Red Last. Population of the Philippine Naked-backed Fruit Bat has declined at least 80% in the past 20 years as inferred from levels of hunting and habitat loss, degradation, and fragmentation—all of which are ongoing and placing continued pressure on population decline. The Philippine Naked-backed Fruit Bat was not recorded between 1964 and 2001, despite intensive surveys, and was considered as Extinct until small extant populations were rediscovered on Cebu and Negros. It has been hunted for local food although public awareness programs are now focused on educating local communities about its conservation value. Several municipal governments contribute to conservation efforts protecting roost caves and surrounding forest as sanctuaries. Municipally appointed conservation officers patrol and report violations of hunting, tree felling, and cave disturbance ordinances. In conjunction with non-government organizations, municipalities have started reforestation programs to increase forest habitat. Lowland forests and karst habitat in the known distribution of the Philippine Naked-backed Fruit Bat have been heavily degraded by logging, agriculture, and mining for copper and gold. Less than 4% of Negros Island remains forested, generally with only small patches of degraded forest remaining. On Cebu, largest remaining fragment of forest in the distribution is ¢.60 ha and is threatened by tree cutting for charcoal and agricultural development. Harvest for local consumption has caused past population declines and continues. More than 50% of respondents to an ethnobiological/hunting survey conducted in Sipalay City admitted they hunted and sold Philippine Naked-backed Fruit Bats in street markets. Since 1995, it has rarely been captured in caves where it was previously hunted. These hunters also indicated that only few individuals have been taken since 2003, suggesting a severe population decline. Guano miners historically have disturbed roosts. It has been bred successfully in captivity for the pet industry, and efforts should be made to develop a well-designed captive breeding program. Additional surveys might locate additional populations on Cebu and Negros.

Bibliography. Alcala et al. (2004), Evans et al. (1993), FFI (2001), Heaney & Heideman (1987), Heaney, Balete et al. (1998), Heaney, Ong et al. (2008), Mallari et al. (2001), Mickleburgh et al. (1992), Paguntalan et al. (2004), Rabor (1952, 1986), Utzurrum (1992).

Figures

73. Lesser Long-tongued Blossom Bat (Macroglossus minimus), 74. Greater Long-tongued Blossom Bat (Macroglossus sobrinus), 75. Southern Blossom Bat (Syconycteris australis), 76. Halmaheran Blossom Bat (Syconycteris carolinae), 77. Moss-forest Blossom Bat (Syconycteris hobbit), 78. Manado Fruit Bat (Boneia bidens), 79. Sulawesi Harpy Fruit Bat (Harpyionycteris celebensis), 80. Philippine Harpy Fruit Bat (Harpyionycteris whitehead), 81. Bulmer’s Fruit Bat (Aproteles bulmerae), 82. Lesser Naked-backed Fruit Bat (Dobsonia minor), 83. Moluccan Naked-backed Fruit Bat (Dobsonia moluccensis), 84. Western Naked-backed Fruit Bat (Dobsonia peronu), 86. Panniet Naked-backed Fruit Bat (Dobsonia pannietensis), 87. Philippine Naked-backed Fruit Bat (Dobsonia chapmani), 88. Biak Naked-backed Fruit Bat (Dobsonia emersa), 89. Sulawesi Naked-backed Fruit Bat (Dobsonia exoleta), 90. Greenish Naked-backed Fruit Bat (Dobsonia viridis), 91. Beaufort’s Naked-backed Fruit Bat (Dobsonia beauforti), 92. Halmahera Naked-backed Fruit Bat (Dobsonia crenulata), 93. Solomons Naked-backed Fruit Bat (Dobsonia inermis), 94. New Britain Naked-backed Fruit Bat (Dobsonia praedatrix)

Distribution. Endemic to the Philippines , where it is known only from Cebu and Negros Is.