2.

Dark-winged Lesser House Bat

Scotoecus hirundo

French: Scotoéque a ailes noires / German: Schwarzflligel-Hausfledermaus / Spanish: Scotoeco de alas negras

Other common names: \\White-bellied Lesser House Bat, Hinde's Lesser House Bat

Taxonomy. Scotophilus hirundo de Winton, 1899,

“Gambaga [Ghana], 1300 feet [= 396 m].”

Scotoecus was considered a subgenus of Nycticetus by J. R. Ellerman and T. C. S. Morrison-Scott in 1951 but subsequently recognized as a distinct genus by D. R. Rosevear in 1965, a treatment followed by J. E. Hill in 1974. Taxonomy of dark-winged Scotoecus has been much debated. In one of the first revisions of the genus in 1953, Ellerman and colleagues placed all dark-winged Scotoecus in S. hirundo . In 1974, Hill divided them into S. hirundo and S. hinder, the second including a subspecies albigula. After evidence of sympatry between hindei and albigula, the latter was raised to species level. However, differences previously recognized as useful for species distinction were subsequently attributed to secondary sexual dimorphism. Against this background, in 1994 K. F. Koopman placed all dark-winged forms in S. hirundo, recognizing four subspecies: hirundo (Senegal to Benin, possibly to Ethiopia); falabae (Nigeria and Cameroon); hindei (South Sudan and Somalia to south-eastern DR Congo); and albigula (Kenya to Angola). In 1998, P. J. Taylor and M. van der Merwe tested Koopman’s arrangement using principal component analysis, which revealed that these forms were morphometrically distinguishable, and this was the basis for recognizing albigula and hinder as full species again. Although N. B. Simmons in 2005 treated albigula and hinde: as full species, in the absence of further evidence, M. Happold’s arrangement from 2013 for African Scotoecus is followed here, which considers albigula and hindei to be synonyms of S. hirundo . Thus, synonyms include albigula, artinu, falabae, and hindei. According to Happold in 2013, external measurements and those of teeth, measured by different authors indicate geographic variation, with increase in size from Ghana / Benin to Sudan / Ethiopia, to Kenya / Tanzania, and on to Malawi. Pelage color also varies, with bicolored hairs in individuals from West Africa, and unicolored hairs in individuals from Malawi. Although no subspecies are recognized here, the taxonomic status of names currently included under S. hirundo requires further clarification. Monotypic.

Distribution. Patchily from Senegal, Gambia, and Guinea-Bissau E to Ethiopia and Somalia and S to S Angola, S Zambia, and S Mozambique.

Descriptive notes. Head-body ¢.49-65 mm, tail 28-40 mm, ear 9-14 mm, hindfoot 8-10 mm, forearm 31-40 mm (males) and 28-37 mm (females); weight 8-15 g. Males average larger than females in some external measurements, have more massive teeth, greater upper tooth row length and molar width. Penis of the Dark-winged Lesser House Bat is extremely long (14-16 mm). Pelage is soft. Wing and interfemoral membranes are blackish brown, slightly translucent. Dorsal pelage is chocolate brown or medium to pale sepia-brown, unicolored (Malawi) or bicolored, with white bases and sepia-brown tips (West Africa). Ventral pelage varies from gray or grayish white to beige or pale beige, with chest sometimes paler than rest of venter. Head is fairly flattened; muzzle is broad, dark brown, and almost naked. Nostrils open to sides from small transverse pads. Eyes are small. Ears are well separated, oval, rounded, and comparatively short for a vespertilionid. Tragus is short (4-6 mm), with anterior margin strongly concave, posterior margin with smooth, obtuse angle above mid-height, and rounded tip. Skull is somewhat flattened but less flattened than in the Light-winged Lesser House Bat (S. albofuscus). C!' has anterior surface flat and is lightly grooved. P? is usually present, displaced lingually, and minute. P* is pointed, and in contact with C'. M® has three ridges. P, is at least two-thirds the height of P,. Dental formula is as in congenersor 11/3, C1/1, P 2/2, M 3/3 (x2) = 32. Two distinct karyotypes have been recorded for specimens tentatively assigned to S. hirundo: D. Koubinova and colleagues in 2013 reported that a male from Senegal had 2n = 30, FN = 50, and FNa = 46, with a metacentric X-chromosome, and a probably acrocentric Y-chromosome, whereas a female from the Ivory Coast reported by M. Volleth and colleagues in 2006 had 2n = 30, FN = 54, and FNa = 50. The specimen tentatively identified as S. hirundo from Senegal differed 1:6% in the rag2 gene in comparison with a specimen from Tanzania, and may represent an undescribed cryptic species.

Habitat. Open woodlands in West Africa, woodlands and deciduous thicket and bushland in the east of its range, and both wetter and drier miombo woodlands in the south of its range. In Malawi, the Dark-winged Lesser House Bat occurs in miombo woodland,relict rainforest, and riverine woodland, gardens,villages and towns. In Nigeria, it occurs in the Guinea savanna zone, especially on the Jos Plateau. Elevational range is 100-1500 m.

Food and Feeding. Dark-winged Lesser House Bats forage by moderately fast hawking, in open spaces, above the canopy, or over grassland, usually 5-25 m aboveground. There 1s no information about diet.

Breeding. In Malawi, restricted seasonal monoestry with early pregnancy in September, pregnancy in October, parturition in November, adult females lactating from November to January, volant young with unfused epiphyses from January to March, adult females post-lactating from February to March, and adults not palpably pregnant from April to June. From September to January, most adult males had abdominal testes; from February to May, most had large scrotal testes. Mating seems to occur around May, followed by sperm storage or reproductive delay until about late August. Litter size 1S two.

Activity patterns. Natural day roosts are not known, but the species is known to roost under corrugated iron roofs of huts and houses. Search-phase call shape of seven Malawian individuals flying in open space after release was very shallow linear FM, occasionally alternated with a curvilinear steep/shallow FM. For very shallow linear FM calls, intensity was high, end frequencies were 30-34 kHz, bandwidths were 2—4 kHz, and call durations were ¢.5-6 milliseconds. For curvilinear steep/shallow FM calls, intensity was high, end frequencies were 32-34 kHz, bandwidths were ¢.6-7 kHz, and call durations were ¢.5—6 milliseconds. When calls were alternated, end frequency was often lower in very shallow linear FM than in curvilinear steep/shallow FM. Approach-phase calls were firstly curvilinear steep/shallow FM sweeps of bandwidth up to 15 kHz, and then steep FM/QCF of greater bandwidth. Calls emitted close to the ground in cluttered areas were steep FM/QCF sweeps, intensity was high, with start frequency up to 70 kHz, and end frequencies of 33-40 kHz. Reflecting the differences in skull size, males echolocate at lower frequencies than females.

Movements, Home range and Social organization. In Masalani, southern Kenya, in 1980, T. J. O’Shea and T. A. Vaughan observed that the abundance of the Dark-winged Lesser House Bat was comparatively low during the long dry season (May-October), and this was preceded by a buildup of subcutaneous fat. These observations led the authors to speculate on emigration from Masalanito places that receive rainfall during May-October (e.g. highlands of western Kenya or the coast). The bedbug Cacodmus sparsilis ( Hemiptera) and the flea Echidnophaga aethiops ( Siphonaptera) have been recorded on this species.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Darkwinged Lesser House Bat is apparently rare in West Africa, but common in Malawi.

Bibliography. Ansell & Dowsett (1988), Ellerman & Morrison-Scott (1951), Ellerman et al. (1953), Happold, M. (2013bh), Hill (1974a), Hill & Harrison (1987), Koopman (1993, 1994), Koubinové etal. (2013), O'Shea & Vaughan (1980), Simmons (2005), Taylor & van der Merwe (1998), Taylor et al. (2005), Volleth et al. (2006).