Dobsonia beauforti, Bergmans, 1975

Don E. Wilson & Russell A. Mittermeier, 2019, Pteropodidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 16-162 : 111-112

91.

Beaufort’s Naked-backed Fruit Bat

Dobsonia beauforti

French: Roussette de Beaufort / German: \Waigeo-Nacktriickenflughund / Spanish: Dobsonia de Beaufort

Other common names: Beaufort's Bare-backed Fruit Bat

Taxonomy. Dobsonia beauforti Bergmans, 1975 ,

“from a cave near Nja-njef, Waigeo [Island, Sorong Division, Papua Province], New Guinea,” Indonesia.

This species is monotypic.

Distribution. Raja Ampat Is (Gebe, Gag, Waigeo, and Batanta), Schouten Is (Biak-Supiori and Owi) off NWNew Guinea;it possibly may be found on MisoolI, a single individual reported from Salawati I probably represents a vagrant.

Descriptive notes. Head-body 120-155 mm, tail 20-28 mm, ear 23-27 mm, forearm 100-114 mm; weight 116-163 g. Males are appreciably larger than females in mean weight (males 158 g and females 133 g) and slightly larger in mean forearm length (males 108 mm and females 106 mm). Breeding males differ from females in having brighter greenish yellow fur, proportionately more massive heads with prominent white cheek glands, and almost naked skin on rest of face. Females tend to be more brownish, have more gracile head that is more heavily furred, and lack inflated cheek glands. Young have green-yellow wash to fur, more similar to adult males. Fur on top and side of head is bone brown to olive-brown (greenish yellow in some descriptions). Nape, shoulders, and furred parts of back are olive-brown and somewhat darker in occipital region and bordering naked skin including narrow strip along spine. Chin is sparsely furred blackish brown. Hairs on throat are drab, and central region of throat has exposed pale skin. Ventral parts of upper arms, shoulders, and flanks are drab, with median patch of Sudan brown on breast and belly. Undersides of propatagium and plagiopatagium have Sudan brown hairs near forearm and between upper arm and body. Claws are light yellowish brown but darkest basally. Index claw (second digit of wing) is absent. Ears, wings, and naked dorsal skin are blackish brown. Nostrils are slightly tubular, and each flares outward from centerline.

Habitat. Primary and secondary tropical moist forests, pandanus palms, coconut and cocoa plantations, and village gardens.

Food and Feeding. Beaufort’s Naked-backed Fruit Bat is frugivorous. Native cluster figs ( Ficus spp. , Moraceae ) and invasive Piper aduncum ( Piperaceae ) are included and probably quite important in its diet. It forages on carambolas ( Oxalidaceae ) and other fruits in village gardens.

Breeding. Seven of 14 Beaufort’s Naked-backed Fruit Bats examined from Waigeo in December were lactating or pregnant. Females observed on Biak in September were in the first trimester of pregnancy. On Batanta, many pregnant females were observed in October.

Activity patterns. Beaufort’s Naked-backed Fruit Bat is nocturnal and roosts in sea and inland caves.

Movements, Home range and Social organization. Beaufort’s Naked-backed Fruit Bat is highly gregarious, sometimes roosting in large colonies of thousands of individuals. It will also roost in smaller groups of tens of individuals in trees.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Beaufort’s Naked-backed Fruit Bat is distributed on a number of islands, presumably has a large population, and is unlikely to be declining at a rate required to qualify for listing in a threatened category. Cave disturbanceis a potential threat. Research is needed on extent of occurrence throughout its distribution and monitoring of population sizes over time to establish whether numbers are stable or experiencing decline. Studies also are needed on habitat requirements, food habits, and effects of forest loss and degradation. Additional taxonomic studies are needed to determine how Beaufort’s Nakedbacked Fruit Bat might be related (or even if some populations thought to represent it) or conspecific with closely related Greenish Naked-backed Fruit Bat (D. viridas).

Bibliography. Bergmans (1975), Flannery (1995a), Maryanto & Kitchener (1999), Mildenstein (2016d).

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. Raja Ampat Is (Gebe, Gag, Waigeo, and Batanta), Schouten Is (Biak-Supiori and Owi) off NWNew Guinea ;it possibly may be found on MisoolI, a single individual reported from Salawati I probably represents a vagrant.