Dobsonia anderseni, 1914

Don E. Wilson & Russell A. Mittermeier, 2019, Pteropodidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 16-162 : 109-110

85.

Andersen’s Naked-backed Fruit Bat

Dobsonia anderseni

French: Roussette d/Andersen / German: Andersen-Nacktrlickenflughund / Spanish: Dobsonia de Andersen

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

Taxonomy. Dobsonia anderseni Thomas, 1914 ,

Manus Island, Admiralty Islands, Papua New Guinea.

K. M. Helgen, cited in D. G. P. Byrnes in 2003, suggested there could be three subspecies of D. anderseni (Admiralty Islands, St. Matthias Island Group, and Bismarck Archipelago), but these taxa have not been described formally. Monotypic.

Distribution. Admiralty Is (Manus), St Matthias Is (Mussau), and Bismarck Archipelago including NE New Guinea offshore Is (Karkar, Bagabag, Tolokiwa, Sakar, and Umboi).

Descriptive notes. Head-body 130-212 mm, tail 15-32 mm, ear 24-38 mm, hindfoot 24-37 mm, forearm 109-135 mm; weight 156-325 g. Andersen’s Naked-backed Fruit Bat is sexually dimorphic; adult breeding age males can be up to 80 g heavier than females. Pelage of head is red-brown, blackish, or gray-brown and tends to be darker in young individuals. Mantle of coarse erect hairs on nape and shoulders is medium brown or red-brown. Fur of upper back is gray-brown; venter is medium brown, with greenish yellow wash along midline. Greenish color, which fades to dull gray/tan in museum specimens, is probably attributable to photosynthetic blue-green algae based on iodine tests that reveal starch-containing globs coating hairs. Wings meet along spine providing naked-backed appearance; back is furred under wing membranes. Claws are white; index claw is lacking. Ear is long and narrow. Upper incisors and P| are very small. Chromosomal complement has 2n = 38 and FN = 68.

Habitat. [Lowland to lower montane moist tropical forests, village gardens, and fruit plantations from sea level up to elevations of ¢. 1500 m.

Food and Feeding. Andersen’s Naked-backed Fruit Batis frugivorous. Native figs are important in diets.

Breeding. On New Britain, pregnant Andersen’s Naked-backed Fruit Bats are observed in March-April and lactating females and offspring in June-August. Lactating females have also been observed in January on Tabar (n = 1) and February on Boang (n = 2) and one pregnant female in July on New Ireland. On Manus, one of six adult females examined was pregnant with small embryo in July, and one of the non-pregnant females showed swollen sebaceous glands on neck and cheeks. A 32-g young is known from January on New Britain. In June-July, adult males on NewBritain have musky smells emanating from swollen glands of thicken and folded skin on necks and cheeks. Males with scrotal testis are reported in March-April on New Britain. This limited evidence suggests a reproductive peak in pregnancy and lactation in March—July on NewBritain.

Activity patterns. Andersen’s Naked-backed Fruit Bat is nocturnal and emerges to forage well after dark. Roosting habitat is in large limestone caves.

Movements, Home range and Social organization. Andersen’s Naked-backed Fruit Bat is gregarious and forms colonies of hundreds or thousands of individuals in twilight zonesof seaside and inland limestone caves. In the Rabaul area of New Britain,it roosts in World WarII era tunnels excavated by theJapanese Imperial Army. It will cohabit cave twilight zones with Geoftroy’s Rousettes ( Rousettus amplexicaudatus ) and glossy swiftlets (Collocalia esculenta). As experimentally demonstrated, Andersen’s Naked-backed Fruit Bat has high thermal conductance (134% of expected for a mammal) based on body weight, thus allowing efficient heat loss for a colonial cave-dwelling species. Basal metabolic rate is 101% of that expected for a mammal based on body weight. Faced with cool ambient temperatures, it thermoregulates to maintain average body temperature of 36-4°C. Andersen’s Naked-backed Fruit Bats are often parasitized by blue-colored ticks (species unknown) that are frequently found clumped on their rumps.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Andersen's Naked-backed Fruit Bat has a large distribution, tolerates habitat modification, and presumably has large and stable or possibly increasing population. Local populations are vulnerable to cave disturbance and hunting for local consumption. Extent and quality of forest habitat continues to decline in its distribution.

Bibliography. Bonaccorso (1998), Byrnes (2005), Flannery (1995a), Helgen, Allison et al. (2008a), McNab & Bonaccorso (2001), Smith & Hood (1981).

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. Admiralty Is (Manus), St Matthias Is (Mussau), and Bismarck Archipelago including NE New Guinea offshore Is (Karkar, Bagabag, Tolokiwa, Sakar, and Umboi).