427.

Welwitsch’s Myotis

Myotis welwitschii

French: Murin de Welwitsch / German: Welwitsch-Mausohr / Spanish: Ratonero de Welwitsch

Other common names: \Welwitch's Bat, Welwitsch's Hairy Bat, Welwitsch’s Mouse-eared Bat

Taxonomy. Scotophilus welwitschii]. E. Gray, 1866,

“ Angola.”

Subgenus Chrysopteron. See M. tricolor and also M. rufoniger. Monotypic.

Distribution. Patchily in sub-Saharan Africa, in SE Guinea, and from Ethiopia and South Sudan through W Uganda, Rwanda, Burundi, S DR Congo, and Angola to N & NE South Africa.

Descriptive notes. Head-body c¢.57 67 mm, tail 55-65 mm, ear 19-25 mm, hindfoot 9- 5-13 mm, forearm 52-60 mm; weight 14-19 g. Sexes similar. Pelage of Welwitsch’s Myotis is dense and woolly, without sheen; dorsally orange (hairs tricolored, cream with blackish-brown base and orange tip; mid-dorsal hairs 7-8 mm); ventrally cream, slightly suffused with orange (hairs bicolored, blackish brown with cream tip). Wings strikingly particolored, with outer arm-wing and hand-wing black, bones outlined in orange, and inner arm-wing orange with small black spots. Wing membranes naked, attached to base offirst toe; interfemoral membrane orange with small black spots, ventral surface with sparse backward-pointing hairs, and posterior margin with sparse fringe of straight, bristle-like hairs between tips of calcars and tip of tail. Ears orange with small black spots and black edges, outer margin without notch, and of medium length; tragus long, bluntly pointed, measuring about one-half ear length. Tibia naked. Muzzle naked, orange with black spots. Skull large and robust (greatest length of skull 18-6-20- 8 mm); profile of forehead moderately concave;sagittal crest low anteriorly, absent posteriorly. P* reduced, being partially or fully displaced lingually; P? and P* separated or in contact; I, and I, with four cusps, three well developed and the fourth low and inconspicuous. Chromosomal complement has 2n = 44 and FNa = 50 (South Africa), X = submetacentric, Y = submetacentric.

Habitat. Typically in Afro-montane habitats at elevations over 2000 m, including forest in much of East and Central Africa, and grassland nearforest in Guinea; up to 2200 m in Ethiopia. Also at lower elevations, occurring in wetter and drier miombo woodland and riverine woodland at 100-1000 m in Malawi; woodland savanna in south-central and southern Africa; and coastal forest surrounded by thornveld in KwaZulu-Natal.

Food and Feeding. Fecal pellets from one bat contained remains of small beetles; captive bats prefer softshelled insects. Recorded flying low over streams and a farm pool, which suggests that the species may forage by trawling over open water like Bocage’s Myotis ( M. bocagii). Wing loading very low, aspect ratio low, flight fast or slow with great maneuverability; able to take off from ground.

Breeding. No information.

Activity patterns. Recorded calls of two individuals from Soutpansberg, South Africa, had the following parameters: maximum frequency 73-8 kHz, minimum frequency 33-8 kHz and 34 kHz,frequency of knee 52-9 kHz and 53 kHz, characteristic frequency 50 kHz and 50-3 kHz, slope 563 OPS, and duration 2-1 milliseconds.

Movements, Home range and Social organization. Welwitsch’s Myotis has been found roosting singly, but data are scarce. During the day, it has been seen hanging in bushes and trees, where well camouflaged by resemblance to dead leaves. In Malawi, one individual was found in furled leaf of banana plant, although there were no other record of banana leaves being used as day roost, despite almost two years of intensive search.

Status and Conservation. Classified as Least Concern on The IUCN Red List.

Bibliography. ACR (2017), Ansell & Dowsett (1988), Csorba, Chou Cheng-Han et al. (2014), Happold, M. (2013bm), Linden et al. (2014), Rautenbach et al. (1993), Ruedi & Mayer (2001), Taylor, Sowler et al. (2013).