4.

Ruppell’s Bat

Vansonia rueppellii

French: Pipistrelle de Riippell / German: Rippell-Zwergfledermaus / Spanish: Pipistrela de vientre blanco

Other common names: Rippell’s Pipistrelle, Rippell's Pipistrelle Bat

Taxonomy. Vespertilio rueppelii [sic] J. B. Fischer, 1829,

Dongola, Northern Province, Sudan.

This species is generally placed in Pipistrellus but has been transferred to its own monotypic genus, Vansonia, based on genetic data showing that it is either a very primitive lineage within Pipistrellini or is sister to a clade including Pipistrellus and Nyctalus . V. rueppellii is also morphologically very distinct from species of Pipustrellus. Six or seven subspecies ( rueppellii, coxi, fuscipes, leucomelas, pulcher, senegalensis, and vernayi) are normally recognized but their validity is uncertain, as are their supposed distributional limits. Analyses have shown that there are insufficient morphological differences to support the recognition of the two North African subspecies ( rueppellii and senegalensis); although the rest ofits range has yet to be tested, no subspecies are recognized here until further evaluation. Monotypic.

Distribution. Known from scattered localities throughout Africa and Middle East, including N Africa from Morocco to Egypt and W Africa (Senegal and Mauritania) E to Sudan and Ethiopia and S throughoutthe rest of sub-Saharan Africa to N South Africa as well as Unguja I (Zanzibar Archipelago), and Middle East in Israel, SE Iraq, Kuwait, extreme SW Iran, Bahrain, and SW Yemen; distribution is probably much more continuous.

Descriptive notes. Head-body 43-56 mm, tail 25-41 mm, ear 6-14 mm, hindfoot 6-10 mm, forearm 28-37 mm; weight 4-9 g. Pelage of Ruppell’s Batis soft, dense, and slick, and dorsal pelage is gray, pale grayish brown, or sepia brown, occasionally with silvery sheen. Ventral pelage is pure white, with throat pure white or pale rusty brown. Ears and face are blackish. Ears are relatively long compared to species of Pipustrellus and tragus is one-half the ear length, with slightly concave anterior margin, a constant breadth, and a rounded tip. Wings are typically translucent pale gray but vary from whitish to medium brown; uropatagium is pale gray and extends to end oftail. Calcar extends to about halfway across uropatagium. Skull is moderately robust compared to African Pipistrellus, braincase is relatively high, with medium relative breadth; interorbital region has a medium relative breadth; lateral profile of forehead region is weakly concave and almost straight; lower molars are nyctalodont; I? is very small; P* is easily visible between C'! and large P*. Dental formulais12/3,C1/1,P 2/2, M 3/3 (x2) = 34. Chromosomal complement has 2n = 36 and FNa = 54.

Habitat. Primarily found in woodland and grassland savannas but can also occur in deserts or montane forests (although forests may be largely avoided when there is no nearby water for foraging over), and along rivers systems. Riippell’s Bat can be found associated with rivers or swamps, for instance in Egypt, Zambia, Botswana, and Zimbabwe, or with streams, ponds, and lakes in montane forests in Malawi. In Mauritania, the species was found in temporary wetlands in Sahelian savanna dominated by Acacia (Fabaceae) formations. In Libya and Egypt,it occurs around permanent oases in the middle of the desert. It has been recorded from sea level to 1700 m throughoutits range.

Food and Feeding. Riippell’s Bat is insectivorous. Foraging occurs generally, if not always, by slow hawking over open water and surrounding grassy/marshy areas. When foraging, flightis straight and fast with frequent swerves, dives, and swoops upward when prey is detected; the species is a very acrobatic flier. Ruppell’s Bat generally flies c. 1 m above the water surface, but will sometimes rise up to 10 m aboveground. Throughoutits range, the species is known to feed predominantly on Lepidoptera, Diptera, Coleoptera, Trichoptera, and Hymenoptera . Analysis of a stomach content from Libya revealed a volume of 50% brachyceran Diptera, 30% Lepidoptera, and 20% nematoceran Diptera .

Breeding. Juveniles have been reported in September and November in Zambia, and young subadults in December in Malawi.

Activity patterns. Foraging is probably crepuscular or nocturnal, although the inclusion of a large amount of the diurnal brachyceran flies indicates that individuals may leave the roost very early to catch diurnal prey. In Egypt, individuals or pairs were found under rocks. In Zambia, one was found behind a board against a wall, and another in the same place several days later. In Malawi, some individuals became torpid during the day when temperatures reached 21-24°C. Call shape is a steep FM/QCF and curvilinear steep/shallow FM in Malawi and steep/shallow FM in Zimbabwe. Call intensity is high, and start frequency is up to 100 kHz, being 70 kHz in many regions (Zimbabwe and South Africa). Calls have end frequencies of 49-53 kHz in Israel and 54-57 kHz in Morocco but range from 40 kHz to 48 kHz throughout much of Africa, usually 46-48 kHz. Call duration was recorded at c.7-3 milliseconds in Malawi and 8 milliseconds in Zimbabwe, and pulse duration was recorded at 4-2 + 0-4 milliseconds in Israel. The bat hawk (Macheiramphus alcinus) has been reported as predator.

Movements, Home range and Social organization. Riippell’s Bats may be primarily solitary, although they can be found foraging over water in groups of up to several dozen, with some individuals following each other. They have been found roosting solitarily or in pairs. The flea Ischnopsyllus emminus has been recorded from this species.

Status and Conservation. Classified as Least Concern on The IUCN Red List (as Pipistrellus rueppellii). Ruppell’s Bat is very widespread and common throughoutits range. A major threat to this species may be the use of pesticidesto kill locusts, which can result in the poisoning of the bats themselves.

Bibliography. Aldridge & Rautenbach (1987), Ansell (1986), Archer (1977), Benda, Hanék et al. (2004), Benda, Ludan et al. (2014), Benda, Reiter et al. (2016), Benda, Spitzenberger et al. (2014), Feldman et al. (2000), Fenton & Thomas (1980), Happold, D.C.D. & Happold (1988), Happold, M. (2013bf), Kearney et al. (2002), Koubinova et al. (2013), Mikula et al. (2016), Monadjem, Aulagnier, Jacobs et al. (2017), Padial & Ibanez (2005), Smithers (1983), Whitaker et al. (1994).