116.

Schlieffen’s Bat

Nycticeinops schlieffenii

French: Vespére de Schlieffen / German: Schlieffen-Abendfledermaus / Spanish: Nicticenop de Schlieffen

Other common names: Schlieffen’s Twilight Bat

Taxonomy. Nycticejus schlieffenii Peters, 1859,

“ Cairo,” Egypt.

Nycticeinops appears to be most closely related to Hypsugo crassulus and H. eisentrauti (both of which may best be moved to Nycticeinops, but see their accounts), which together are sister to a clade including Neoromicia and Laephotis based on limited genetic data. Karyological studies have revealed different diploid and fundamental numbers for an individual from Somalia in comparison with 22 from South Africa; this may indicate that the two populations represent distinct species, or that the identity of the Somali specimen is erroneous. Four subspecies have been tentatively proposed based on patterns of pelage color. Synonyms include adovanus, africanus, albiventer, australis, bedouin, cinnamomeus, fitzsimonsi, and minimus. Monotypic.

Distribution. S Mauritania E to N Somalia (including isolated population in N Egypt) and S to N Namibia, N Botswana, and NE South Africa; also SW Arabia.

Descriptive notes. Head-body 37-48 mm, tail 24-34 mm, ear 9-13 mm, hindfoot 7-8 mm, forearm 28-35 mm; weight 4-9 g. Females average heavier than males. Schlieffen’s Bat is among the smallest bats in Africa. Pelage color varies geographically; dorsally, head and body are brown to light brown and hairs are unicolored; ventrally paler brown to grayish white to white. Muzzle is flattened, sparsely haired anteriorly and with prominent lateral glandular swellings; nares are obliquely opened. Ears are dark brown. Wings and interfemoral membrane are dark brown with blackish-brown venation; free edge of interfemoral membrane sometimes has faint white border. Ears are rounded with small, posteriorly oriented basal lobe; tragus is pointed, with strongly convex posterior margin and prominent basal lobe. Calcar extends over one-half of border of uropatagium. This species can be distinguished from the North American Evening Bat ( Nycticeius humeralis) by baculum with expanded base and long fluted shaft, as well as shorter rostrum, narrower cranium, and maxillary tooth row more convergent. It can be distinguished from Scoteanax and Scotorepens by baculum without modified tips, and reduced molars. I* is fairly long and unicuspid; C' and C, are robust; C' has anterior surface rounded and not grooved; P* is sharply pointed, reaching twothirds to three-quarters the height of C'; M® has three ridges (cf. Scotophilus); lower incisors are tricuspid; and P, is about one-half the height and one-half the crown area of P, (ct. Scotoecus). Dental formulaisI11/3,C1/1,P 1/2, M 3/3 (x2) = 30. Chromosomal complement has 2n = 42 and FNa = 50 (South Africa) or 2n = 34 and FNa = 52 (Somalia).

Habitat. North of equator, Schlieffen’s Bat occurs mainly in Sudanian woodlands, penetrating into arid areas through riparian vegetation (otherwise not usually found in forested habitats). South of equator,it occurs in semi-desert grassland and shrubland, but absent from most arid areas. It is usually found at elevations of up to 900 m in south of range, extending to 1000 m on Central African Plateau in Malawi.

Food and Feeding. Schlieffen’s Bat forages 2-6 m aboveground in open areas, between larger branches and tree trunks, near surface of branches and leaves of trees and bushes, in clearings over floodplains and over water. In Zimbabwe, it was found foraging in riparian forests, over floodplains, and above open water during dry season. It apparently takes a variety of insects, including Lepidoptera, Coleoptera, Diptera, Hemiptera, Trichoptera, and Hymenoptera .

Breeding. Schlieffen’s Bat is seasonally monoestrous. In Kruger National Park, northeastern South Africa, copulation begins in winter (around June). Females store spermatozoa in uterine horns until ovulation occurs in late August; births occur during summer (November—-December). Gestation lasts c.11 weeks. Litter size is 1-3.

Activity patterns. Schlieffen’s Bats have been found in torpor during the day at temperatures of 21-24°C. Roosts include hollow branches, rock crevices, and cracks and crevices inside hollow trees, roofs, and cellars. In Malawi, search-phase call shapes are smooth steep/shallow FM, with the following parameters for bats flying in open areas: intensity high, start frequencies of 46-64 kHz, end frequencies 38-43 kHz, peak frequencies 38-41 kHz, and call durations mostly 7-9 milliseconds. For bats flying near the ground call shape becomes steep FM/QCEF, with the following parameters: start frequencies up to 76 kHz, end frequencies 38-42 kHz, and call durations mostly 5-6 milliseconds. In Zimbabwe and Kruger National Park, call shape of bats flying in open areas is steep FM/QCEF, with start frequency of ¢.78 kHz, end frequency c¢.33 kHz, and peak frequency c.42 kHz. In Swaziland,call shape is steep FM, with start frequency of 45-5 kHz (mean), end frequency 39-5 kHz, peak frequency 41 kHz, and call duration 3-7 milliseconds. Predators include bat hawks (Macheiramphus alcinus).

Movements, Home range and Social organization. Schlieffen’s Bats roost alone, in pairs, in small groups, or in large numbers. Bats occasionally congregate to forage. In Malawi, a maternity colony of c.40 post-lactating females and their young was found in a rooftop. Schlieffen’s Bats have occasionally been found roosting with African Sheathtailed Bats (Coleura afra), Mongalla Free-tailed Bats (Mops demonstrator), and Midas Free-tailed Bats (M. midas).

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

Bibliography. Fenton (1975), Happold (2013bd), Hayman & Hill (1971), van der Merwe & Rautenbach (1987), O'Shea & Vaughan (1980), Rautenbach et al. (1993), Ruedas et al. (1990).