113. Mouse-like Pipistrelle Hypsugo musciculus French: VVespéere murine / German: Mauschen-Zwergfledermaus / Spanish: Hypsugo murino Other common names: Least Pipistrelle Bat, Western Africa Pipistrelle Taxonomy. Pipistrellus musciculus Thomas, 1913, “Bitye, Ja River, Camaroons [= Cameroon]. Alt. 2000’ [= 610 m].” Relationships with other African Hypsugo, Neoromicia, or Nycticeinops are uncertain; further study is needed, using genetic and morphological data of this species. Monotypic. Distribution. W Sierra Leone, SW Ghana, SC Cameroon, NE Gabon, and two records from W DR Congo (one of these may represent the Banana Serotine, Neoromicia nanus). Descriptive notes. Head-body c. 40 mm, tail 21-26 mm, ear 8-11 mm, forearm 23-26 mm; weight 3-8 g (one specimen). Pelage of the Mouse-like Pipistrelle is soft and dense; dorsal and ventral pelage is dark umber brown (hairs are unicolored). Bare portions of face, ears, and membranes are blackish brown. Ears are subtriangular, and inner margin is strongly convex basally, then becoming straight; tragus is about onethird the height of ear, and is narrow, with straight anterior margin, smoothly convex posterior margin, and rounded tip. Uropatagium extends more or less to tail tip; calcar has well-developed postcalcarial lobe. Penis is relatively short. Skull is comparatively small and gracile; braincase is fairly high and wide; interorbital region is quite broad; rostrum is relatively short and wide; forehead is weakly concave. I? is bicuspid and subequal in size to I’; P? is minute, not visible above gum, intruded from tooth row, and occasionally absent; and lower molars are myotodont. Dental formula is as in congeners, but sometimes 12/3, C 1/1, P1/2, M 3/3 (x2) = 32, Habitat. The Mouse-like Pipistrelle is mainly known from rainforest but has been recorded in Guinea savanna in Sierra Leone. Food and Feeding. A group of 4-5 individuals foraged together near the ground. Breeding. A lactating female was captured in mid-May in Sierra Leone; a female with two young was captured in June (locality unrecorded; museum specimen). Activity patterns. A male and female with two young were captured in hollow stem of a West African piassava palm (Raphia vinifera, Arecaceae). The speciesis a veryrapid flier. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Data Deficient on The IUCN Red List (as Pipistrellus musciculus). Very little is known; further research is needed. Bibliography. ACR (2018), Grubb et al. (1998), Hayman et al. (1966), Jacobs et al. (2008g), Van Cakenberghe & Happold (2013k), Van Cakenberghe et al. (2017).

Published as part of Don E. Wilson & Russell A. Mittermeier, 2019, Vespertilionidae, pp. 716-981 in Handbook of the Mammals of the World – Volume 9 Bats, Barcelona :Lynx Edicions on page 815, DOI: 10.5281/zenodo.6397752