Dyacopterus rickarti, Helgen et al., 2007

Don E. Wilson & Russell A. Mittermeier, 2019, Pteropodidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 16-162 : 72

17.

Philippine Large-headed Fruit Bat

Dyacopterus rickarti

French: Cynoptere de Rickart / German: Philippinen-Dayak-Flughund / Spanish: Dyacoéptero de Rickart

Other common names: Rickart's Dayak Fruit Bat

Taxonomy. Dyacopterus rickarti Helgen et al, 2007 ,

“San Isidro (17°27'N, 120°37’E), Luzon (Abra Province), Philippines.”

This species is monotypic.

Distribution. Philippines, suspected to be widespread in the archipelago, but so far recorded in only one locality on Luzon I and four localities on Mindanao I.

Descriptive notes. Head-body 130- 144 mm, tail 18-29 mm, ear 21-25 mm, hindfoot 25 mm, forearm 91-96- 4 mm; weight 138-148 g. Muzzle of the Philippine Large-headed Bat is stout, almost hairless, with grayish brown skin; nostrils are shortly tubular and divergent, with thickened rims and obvious philtrum, reaching upper lip that has faint, inconspicuous white mustache of very sparse hairs; lower lip has very large but not prominent paired pads and other small papillae. Eyes are moderately large; iris is dark brown. Ears are short and grayish brown, with pointed tips. Head is massive, very wide, and divided by obvious temporal muscles. Head pelage is very short and grayish brown and continues on nape, becoming warm brown along dorsum. Tail is long, surpassing wide uropatagium; calcar is short. Throat and chest are sparsely haired and light brown that becomes darker on flanks; belly is pale brown to cream. Small tuft of longer, warm brown hairs occurs on shoulder. Wing membranes are dark gray from sides of body and attach to second toe, index claw is present, and all claws are unpigmented and whitish. Skull has no basicranial deflection, is generally very robust, and long posteriorly. Laterally, premaxillae are fused; narial opening is deeply concave; rostrum is very deep, ascending and continued into flat forehead; juga of canine and cheekteeth roots are obvious; orbit is large, with well-marked rim; zygomatic root is above upper alveolar line; zygoma is strongly arched; and braincase is low and elongated. Dorsally, rostrum widens posteriorly, paranasal recesses are inflated, postorbital foramen is absent, postorbital constriction is obvious, postorbital processes are thick and divergent, forehead looks like a shield, temporal lines are joined in sharp sagittal crest, and braincase is oval and elongated, ending in marked nuchal crest. Ventrally, palate is flat; tooth rows diverge; post-dental short and converging, without palatine spine; sphenoidal crest is low; and ectotympanic is very wide, especially anteriorly, and internally edged by ribbon-like entotympanic. Mandible is stout; symphysis slopes, continuing in a convex ventral border; coronoid slopes steeply, almost vertical, and tip is rounded; condyle is strong, above lower alveolar line; and angle is stout, with marked rim. There are 15-16 palatal ridges, with posterior and some anterior ridges divided. Upper incisors are small and crowded; I' is longest; C' is straight and proclivous, has well-developed vertical groove on its anteromedial surface and obvious cingulum and posterolateral basal cusp; P' is absent; next premolar (P?) is massive, stout, high-crowned, very wide, and square in outline; last premolar has anteromedial cingular ledge; and M' is more elongated and low crowned. Lower incisors are very small and spaced; C, is short, stout, and strongly decurved; P, is relatively large and wide; posterior cheekteeth are massive, changing from high-crowned triangular outline to very wide, square outline in last premolar, to more elongated, low-crowned M; and M,is peg-like.

Habitat. Primary and regenerating montane and mossy rainforest at elevations of 260- 1680 m. The Philippine Large-headed Batis suspected to use subcanopy and canopy strata.

Food and Feeding. The Philippine Large-headed Bat is primarily frugivorous, probably relying on figs ( Ficus spp. , Moraceae ) and hard fruits,judging from its robust skull and dentition.

Breeding. A pregnant Philippine Large-headed Bat with one young was captured in May.

Activity patterns. The few captures of Philippine Large-Headed Bats suggest that it uses open areas as flyways.

Movements, Home range and Social organization. No information.

Status and Conservation. Not assessed on The [UCN Red List. The Philippine Largeheaded Bat was included under the Common Dayak Fruit Bat ( D. spadiceus ), which was classified as Near Threatened. Additional research is needed to evaluate conservation status of the Philippine Large-headed Bat, which is rare and infrequently captured. Present in some protected areas; e.g. Mount Kitanglad Range Nature Park (Mindanao).

Bibliography. Heaney, Balete & Rickart (2016), Heaney, Tabaranza et al. (2006), Helgen et al. (2007), Kock (1969a).

Figures

15. Brooks's Dayak Fruit Bat (Dyacopterus brooksi), 16. Common Dayak Fruit Bat (Dyacopterus spadiceus), 17. Philippine Large-headed Fruit Bat (Dyacopterus rickarti), 18. Blanford’s Fruit Bat (Sphaerias blanfordi), 19. Bornean Spotted-winged Fruit Bat (Balionycteris maculata), 20. Malayan Spotted-winged Fruit Bat (Balionycteris seemundi), 21. Bornean Pygmy Fruit Bat (Aethalops aequalis), 22. Common Pygmy Fruit Bat (Aethalops alecto), 23. Common Swift Fruit Bat (Thoopterus nigrescens), 24. Suhaniah’s Swift Fruit Bat (Thoopterus suhaniahae), 25. Mindanao Pygmy Fruit Bat (Alionycteris paucidentata), 26. Fischer’s Pygmy Fruit Bat (Haplonycteris fischeri), 27. Luzon Pygmy Fruit Bat (Otopteropus cartilagonodus), 28. Salim Ali’s Fruit Bat (Latidens salimaliz), 29. Sundaic Black-capped Fruit Bat (Chironax melanocephalus), 30. Sulawesi Black-capped Fruit Bat (Chironax tumulus), 31. Lucas’s Short-nosed Fruit Bat (Penthetor lucasu)

Distribution. Philippines , suspected to be widespread in the archipelago, but so far recorded in only one locality on Luzon I and four localities on Mindanao I.