Cheiromeles parvidens, G. S. Miller & Hollister, 1921

Don E. Wilson & Russell A. Mittermeier, 2019, Molossidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 598-672 : 621

2.

Lesser Naked Bat

Cheiromeles parvidens

French: Chiromeéle a dents courtes / German: Sulawesi-Nacktfledermaus / Spanish: Queirémelo pequeno de espalda desnuda

Other common names: Sulawesi Mastiff Bat

Taxonomy. Cheiromeles parvidens G. S. Miller & Hollister, 1921 ,

“Pinedapa, Middle Celebes [= Sulawesi],” Indonesia .

Cheiromeles parvidens included C. torquatus , but it is smaller in size, and distributions are disjunct. Monotypic.

Distribution. Philippines (Mindoro, Negros, Mindanao, and Jolo and Tawi-Tawi Is in the Sulu Archipelago) and Sulawesi, including nearby Buton and Sanana Is.

Descriptive notes. Head-body 104-5-115-4 mm, tail 54-3-64-1 mm, ear 24-1-29 mm, hindfoot (without claw) 21-23 mm, forearm 69-478 mm; weight 73-100 g. Body of the Lesser Naked Bat appears naked but is covered in very fine short hairs, particularly on undersides. Skin is dark brown to dark gray, and although smooth dorsally, there are thick loose folds on underside, particularly near genitals. There is a patch of stiff hairs or bristles associated with gular pouch, in which there is glandular structure, and bristles of short stiff hairs with spatulated ends on hallux of hindfeet, presumably used for grooming. Ears are not joined over top of head and are oriented laterally and slightly forward. Skull is broad, with well-developed sagittal crest and powerfuljaws. Lips are smooth, and upperlips appear to project over lowerlips to present an “overbite.” Wings are long, narrow, and folded when an individual is at rest such that third and fourth phalanges are tucked into subaxillary pouches formed by attachment of plagiopatagium dorsally rather than laterally; attachment runs from upper arm to thigh. Pouches open posteriorly, and tensor plagiopatagia muscle can tighten opening to stabilize position of folded wing. When wings are folded, an individual can move quadrupedally using pad at base of thumb and hindlimbs. Sturdy hindlimbs are angled such that feet project laterally, wings can be folded, and phalanges tucked away, and thumbs have thickened pads. Calcar might play a role in supporting shank for quadrupedal motion. Hallux of hindfootis set at almost a right angle to the rest of digits, appearing opposable and creating hand-like appearance from which the genus got its name (Greek for badger hand); this might assist with tucking wingtips into the pouch, terrestrial locomotion, moving backward up trees, and arboreal locomotion. Reverse climbing behavior is known for the related and morphologically very similar Greater Naked Bat ( C. torquatus ). Hindlimbs are short, stocky, and very strong; shank is angled anterodorsally, supporting quadrupedal movements (walking on “all fours”) and climbing. M? has third ridge highly reduced. Dental formulas 1/1, C1/1,P 1/2, M 3/3 (x2) =26.

Habitat. Probably agricultural and forested areas from sea level up to elevations of¢. 200 m.

Food and Feeding. The Lesser Naked Bat is an aerial insectivore that forages fast and high in open spaces over and well above vegetation. It has been captured in mist-nets set over slow-moving rivers. Dietary data are unavailable, but strong jaws, well-developed canines, and enlarged temporal muscles are adaptations that would enable it to puncture and crunch hard-shelled prey such as beetles.

Breeding. Lesser Naked Bats presumably have two young per pregnancy that are left in roosts when females leave to forage.

Activity patterns. Captures suggest that Lesser Naked Bats are actively foraging, at least overrivers, in the first 1-2 hours after dusk. Activity might continue throughout the night. It is known to roost in hollow trees, coconut palms, and occasionally caves.

Movements, Home range and Social organization. The Lesser Naked Bat shares morphological adaptations for quadrupedal and arboreal movement as seen in the Great er Naked Bat. Large heavy body and long narrow wings suggest high wing loading and low aspect ratio—parameters that facilitate fast efficient flight. Therefore, it is likely that Lesser Naked Bats forage far from day roosts, possibly tens of kilometers per night, although there are no direct observations. Social organization is unconfirmed, but colonial roosting seems probable based on clustered patterns of captures, and gregarious behavior of the related Greater Naked Bat. Secretions from gular sac, genital folds, and subaxillary pouch are extremely pungent and unpleasant to most people but probably play roles in social communication. Collections from Mindanao Island, Philippines, confirm association between commensal earwigs Arixenis camura and Xeniaria bicornus (Arixeniina, Dermaptera) and Lesser Naked Bats. Arixenis camura might exploit some product of glandular skin because its mouthparts are reduced and largely adapted for brushing rather than masticating. Based on mouthpart morphology, Xeniaria insects are believed to be consuming insects in bat roosts.

Status and Conservation. Classified as Least Concern on The IUCN Red List. There is very little information on population status of the Lesser Naked Bat, but deforestation is occurring throughout its distribution. It is hunted for consumption in Sulawesi.

Bibliography. Corbet & Hill (1992), Csorba, Bumrungsri, Francis, Bates, Gumal & Kingston (2008d), Flannery (1995a), Freeman (1979), Heaney et al. (2010), Ingle & Heaney (1992), Nakata & Maa (1974), Nowak (1999), Schutt & Simmons (2001), Simmons & Cirranello (2018).

Figures

1. Blunt-eared Bat (Tomopeas ravus), 2. Lesser Naked Bat (Chewromeles parvidens), 3. Greater Naked Bat (Chewromeles torquatus), 4. Peters’s Little Mastff Bat (Mormopterus jugularis), 5. Reunion Little Masuft Bat (Mormopterus francoismoutoui), 6. Mauritian Little Mastiff Bat (Mormopterus acetabulosus), 7. Sumatran Little Mastift Bat (Mormopterus doriae), 8. Least Little Mastiff Bat (Mormopterus minutus), 9. Kalinowski’s Little Mastiff Bat (Mormopterus kalinowskii), 10. Incan Little Masuft Bat (Mormopterus phrudus), 11. Alvarez’s Mastff Bat (Molossus alvarez), 12. Aztec Mastff Bat (Molossus aztecus), 13. Coiban Mastuff Bat (Molossus cotbensis)

Distribution. Philippines (Mindoro, Negros, Mindanao, and Jolo and Tawi-Tawi Is in the Sulu Archipelago) and Sulawesi, including nearby Buton and Sanana Is.