Lavia frons (E. Geoffroy Saint-Hilaire, 1810)

Don E. Wilson & Russell A. Mittermeier, 2019, Megadermatidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 182-192 : 190-191

1.

Yellow-winged False-vampire

Lavia frons

French: Mégaderme a ailes orangées / German: Gelbflligelfledermaus / Spanish: Megaderma de alas amarillas

Other common names: African Yellow-winged Bat, Yellow-winged Bat

Taxonomy. Megaderma frons E. GeoffroySaint-Hilaire, 1810 ,

“ Sénégal.”

Two subspecies, in addition to nominate Jfroms, are recognized by some authors, mostly based on small differences in size; however, no review of population boundaries or genetic comparisons have been undertaken. Three subspecies recognized.

Subspecies and Distribution.

L. J fons E. Geoffroy Saint-Hilaire, 1810 — Senegal and Gambia E to Nigeria, Cameroon, and Central African Republic, and S to SW Republic ofthe Congo.

L.f.affinisK.Andersen&Wroughton,1907—Chad,Sudan,SouthSudan,NUganda,andextremeNEDRCongo.

L. f. rex G. S. Miller, 1905 — Eritrea, Ethiopia, and Somalia S through E DR Congo, Kenya, and Tanzania (including Unguja I in Zanzibar Archipelago) to N Zambia and N Malawi. A published report from Namibia is considered an error.

Descriptive notes. Head—body 60-83 mm(tailless), ear 33-47 mm, hindfoot 16-20 mm, forearm 53-64 mm; weight 28-36 g. Females average slightly larger than males. The Yellow-winged False-vampire is distinctive and mediumto largein size, with tall erect noseleaf, large ears joined overhead, and long woollygrayfur having pale tips and dark bases. Fur oflower back is often mixed with yellowish color. Ventral pelageis paler, sometimes with yellow tinge. Wing membranes, ears, and noseleaf are yellowish to yellow brown. Noseleafis more than twiceas high as wide. Top ofposterior noseleafis squared off, with slightly raised corners. Sides of posterior noseleafare continuous with anterior noseleaf and have no indentation onsides. Anterior noseleafhas raised fold and notch in center, Just above lip. There is a thickened ridge down the middle ofnoseleafthat is narrowat top and expanded at basejust above nostrils, forming a spoon-like shape. Tragus is deeply forked, with short pointed innerlobe and elongated pointed outerlobethat is morethan one-half the ear length. Eyes are verylarge, with reflective tapetum lucidum that likely allows themto see well at night. Males have gland on lower back that produces yellowish secretion with distinctive odor. Baculum has mediumshaft with two prongs. Rostrum of skull has a largefrontal shield with shallow median depression and enlarged, broad preorbital and postorbital processes. C' has very small anterolingual cusp; P? is lacking; M! has well-developed mesostyle situated labially. Coronoid process of mandibleis equal in height ortaller than C.. Dental formulais10/2,C1/1,P 1/2, M3/3 (x2) = 26.

Habitat. ‘Tropical savannas and open woodlands from sea level up to elevations of ¢. 2000 m. In someareas, Yellow-winged False-vampires are found mainlyin riparian forests along streams, rivers, swamps, and lakes, whereas in others distributionis related to availability ofacacia trees ( Acacia , Fabaceae ). Not reported fromtall rainforest.

Food and Feeding. The Yellow-winged False-vampire eats insects, primarily larger species such as orthopterans, termites, beetles, moths, and butterflies but also smaller species such as flies. It hunts by hanging from a perch, swiveling its head to locate prey, and then flying out to catch it. Prey is taken back to the perch where it is consumed. Prey is mainly caught in flight but occasionally captured on vegetation or the ground. Typical prey-catching flights last 3-4 seconds and cover 15-20 m, often well above the bat suggesting prey is detected visually silhouetted against the sky, rather than by echolocation. The Yellowwinged False-vampire often forages around dusk, in much brighter conditions than most other bats, sometimes at the same time as diurnal birds such as drongos (Dicrurus spp.).

Breeding. A single young is typically born after a gestation period of 3-3-5 months. In Kenya, newborns were reported in early April, just before the rainy season started when food became most abundant. Courtship behavior was observed in May and June suggesting the possibility of a second birth period in October or November coinciding with the second rainy season. In Tanzania, births have been reported in January, April, August, and November, also suggesting two breeding periods. In north-eastern DR Congo, births have been documented in April. Young cling to its mother until c.5 weeks old, holding in its mouth one of the mother’s inguinal false nipples, and wrapping its legs around her neck. Periodically it turns upside down to suckle. Females carry their small young while foraging. Young older than five weeks are left at the roost while the mother forages. At age 6-7 weeks, young begin to forage for prey by themselves but often accompanied by their parents. Young remain with their parents for up to three months while they learn to hunt.

Activity patterns. Yellow-winged False-vampires roost during the day, but adults remain alert, with their eyes open, rotating slowly from side to side and scanning surroundings with their ears and eyes to detect possible threats. They often fly or climb short distances during the day to change roosting branches. This likely has a thermoregulatory function. They select sunny areas in the early morning and on cool days and shady areas during hot periods. They actively forage at night from 30-40 minutes before sunset to ¢.10 minutes before sunrise. When food is plentiful, such as during termite swarms, adults may become satiated within 30 minutes of dusk and return to a roost for much of the night. They have been reported to feed opportunistically during the day on insects disturbed by bush fires. In Kenya and northern Tanzania, Yellow-winged False-vampires roost during the day mainly in acacia ( Acacia ), hanging from small branches typically thinner than 1 cm in diameter 5-10 m aboveground. They also reportedly roost in shrubs under larger trees and occasionally in hollow trees or buildings. Echolocation pulses used for navigation and presumably prey detection are short (3-2 milliseconds) FM calls with most energy in second and third harmonics. Peak energy in second harmonic is at 42 kHz, with typical bandwidth of c.13 kHz, sweeping from 48 kHz to 35 kHz. First harmonic (fundamental) is much softer but sometimes has enough energy below 20 kHz to be audible to humans with good hearing. Larger males tend to have lower frequency echolocation calls. There are reports of predation on this species by falcons, bat hawks (Macheiramphus alcinus), and snakes.

Movements, Home range and Social organization. Pairs or single males defend territories in which they roost and forage. The Yellow-winged False-vampire is not migratory and,at least in Kenya where it has been studied most intensively, appears to maintain the same territory throughout the year. Territories are 0-6-1 ha, with adjacent pairsstaying at least 20 m apart from each other. In the morning around sunrise, males reportedly patrol edgesoftheir territories, moving from tree to tree and actively chasing away any potential intruding conspecifics. It is socially monogamous and typically found in pairs. Members of a pair often roost within 1 m of each other. Groups of up to five individuals have been reported in some areas, but composition of those groups has not been verified.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Populations of Yellow-winged False-vampires are apparently stable, but there is no quantitative data on population trends.

Bibliography. Kingdon (1974), Smarsh & Smotherman (2015), Vaughan (1987), Vaughan & Vaughan (1986, 1987), Vonhof & Kalcounis (1999), Wickler & Uhrig (1969).

Figures

1. Yellow-winged False-vampire (Lavia frons), 2. Heart-nosed False-vampire (Cardioderma cor), 3. Lesser Asian False-vampire (Megaderma spasma), 4. Greater Asian False-vampire (Lyroderma lyra)

Subspecies and Distribution. L. J fons E. Geoffroy Saint-Hilaire, 1810 — Senegal and Gambia E to Nigeria , Cameroon, and Central African Republic , and S to SW Republic ofthe Congo . L.f.affinisK.Andersen&Wroughton,1907—Chad,Sudan,SouthSudan,NUganda,andextremeNEDRCongo. L. f. rex G. S. Miller, 1905 — Eritrea , Ethiopia , and Somalia S through E DR Congo , Kenya , and Tanzania (including Unguja I in Zanzibar Archipelago) to N Zambia and N Malawi . A published report from Namibia is considered an error.