431.

Bocage’

Myotis

Myotis bocagii

French: Murin de Du Bocage / German: Bocage-Mausohr / Spanish: Ratonero de Bocage

Other common names: Bocage's Banana Bat, Bocage's Hairy Bat, Bocage's Mouse-eared Bat, Rufous Hairy Bat, Rufous Mouse-eared Bat, Rufous Mouse-eared Myotis, Rufous Myotis

Taxonomy. Vespertilio bocagii Peters, 1870,

Duque de Braganca, Angola.

Subgenus Chrysopteron. See M. tricolor and M. scotti . The forms dogalensis and hildegardeae are treated as synonyms of bocagii . Two subspecies recognized.

Subspecies and Distribution.

M.b.bocagiiPeters,1870—SYemenandmostofsub-SaharanAfricafromEthiopiatoAngolaandStoNESouthAfrica.

M. b. cupreolus Thomas, 1904 —- W & C Africa from Senegal to DR Congo.

Descriptive notes. Head-body ¢. 50-53 mm, tail 30-50 mm, ear 12-16 mm, hindfoot 11-12 mm, forearm 33-42 mm; weight 5-10 g. Greatest lengths of skulls are 13-6 15- 9 mm. Females average, slightly larger than males. Pelage is soft, dense and silky; dorsally pale brownish gray (hairs bicolored, with basal half blackish-brown, and distal half pale brownish-gray; mid-dorsal hairs 6-7 mm); ventrally white to yellowish, sharply delineated from dorsal pelage, especially between ear and shoulder (hairs bicolored, blackish-brown with white to yellowish tip). Juveniles are dorsally darker and browner than adults. Wings uniformly grayish brown without markings; attached to distal end of tibia, clearly above heel; interfemoral membrane grayish brown, thickly covered by brown downy hairs, particularly near body. Ears are grayish brown, short for an African Myotis, outer margin with slight notch; tragus Sshaped with bluntly pointed tip, measuring about half ear length. Muzzle naked from prominent nostrils to eyes, rufous-brown to dark-gray. Tibia hairy, particularly on outer edge; hindfeet relatively large, measuring 70-83% of tibia length. Skull small; braincase comparatively low, profile of forehead moderately to strongly concave; no sagittal crest. P* comparatively large, measuring about half to three-quarters the height of P?, and much more than half the crown area of P?*, usually displaced lingually, but P? and P* well separated; P? also displaced lingually. I, and I, with four cusps. Chromosomal complement has 2n = 44 and FNa = 50 (South Africa), X submetacentric, Y acrocentric.

Habitat. Common where forest, banana plants and open water are present. Recorded from riverine habitats in lowland rainforest and woodland savanna in West Africa, coastal forests in East Africa, and miombo woodland and savanna in the south.

Food and Feeding. Lepidoptera, Coleoptera, Hemiptera, Diptera, and Trichoptera were eaten in summer and winter at Umbilo River, KwaZulu-Natal (South Africa). The species forages mainly by trawling and slow-hawking over water, capturing insects from water surface (orjust below) or, less often, above it, perhaps using hindfeet. Wing loading very low, aspectratio low; flight fast or slow, with great maneuverability; able to take off from the ground. In Malawi, a marked bat foraged over a large farm dam for more than 1-5 hours with only one four-minute break after 55 minutes’ foraging.

Breeding. Litter size usually one; one record of two. In Makokou, Gabon, a marked female that gave birth in January was pregnantin the following June, and three other marked females gave birth three times within two years. Based on this evidence, the reproductive chronology is polyestry with births in December—February and June. These periods comprise the two drier seasons, when insects are concentrated in the vicinity of rivers and marshes, providing optimal foraging. In north-eastern DR Congo, a pregnant female was recorded in early January and a birth in June. In Equatorial Guinea, a pregnant female in late pregnancy was seen in late January and a young bat in June. In Malawi, one of three adult females was pregnant in September; one of one was pregnant in October; two of five were pregnant, one was lactating, one was postlactating and one was inactive in January; one of one was post-lactating in February; two of eight were post-lactating and six were reproductively inactive in March; six ofsix were parous but reproductively inactive in May. Based on these data, polyestry seems unlikely unless two births occur within the November—March wet season. A male with scrotal testes was collected in East Usambara Mountains, Tanzania,in July.

Activity patterns. Day roosts include furled leaves of bananas and other musaceous plants, bunches of bananas and under dead leaves of bananas and plantains. The species has also been found clinging to broad leaves in dank, dark vegetation of a thickly overgrown swamp; also roosts among leaves of Hyphaene (Arecaceae) palms and in hollow trees. Average peak frequency of calls is 43-2 kHz, with duration of 2 milliseconds (Durban, South Africa); minimum frequency 30-1 kHz, frequency of knee 41-2 kHz, characteristic frequency 36-6 kHz, and duration 2-8 milliseconds for one specimen in Swaziland.

Movements, Home range and Social organization. In Makokou, north-eastern Gabon, bats roosted in furled banana leaves in plantations along Ivindo River, over which they foraged at night. Although banana leaves open after a few days, clumps of bananas produce new leaves often enough to allow bats to move into a new leaf, showing roostfidelity to particular clumps. Bats lived in harems comprising one adult male and 2-7 adult females and their young, the entire group roosting together in one furled leaf. Adult males that are not in harems roost singly, sometimes near harems. Each harem occupies a distinct clump of bananas, the distance between harems being 600-1000 m. Females remained very stable over the study period, whereas males were replaced more often.Juveniles left the parental harem at ¢.4-5 months old. Two of ninejuvenile males that were marked in their parental harems, returned when one year old and became “harem-masters.” In formation of harems, adult females outnumbered adult males. As sex ratio at birth was balanced, mortality is probably higher in males than females. Roosts are not in short supply; prime feeding territories over stretches of the river near roosting sites may be limited and worth defending, influencing the harem structure.

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

Bibliography. Brosset (1976), Csorba, Chou Cheng-Han etal. (2014), Happold, M. (2013bk), Monadjem, Shapiro et al. (2017), Naidoo et al. (2011), Schoeman & Waddington (2011), Simmons (2005), Stanley & Goodman (2011).