114.

Broad-headed Pipistrelle

Hypsugo crassulus

French: Vespere a grosse téte / German: Breitkopfige Zwergfledermaus / Spanish: Hypsugo cabezudo

Taxonomy. Pipistrellus crassulus Thomas, 1904,

“Efulen, Cameroons [= Cameroon].”

Relationships are currently unresolved. Genetic data place race bellieri close to Hypsugo aisentrauti (but see H. eisentrauti). Nominate crassulus has not yet been included in a phylogenetic analysis; bellieri might represent a distinct species. Two subspecies recognized.

Subspecies and Distribution.

H.c.crassulusThomas,1904—scatteredrecordsinSCameroon,SGabon,SRepublicoftheCongo,NWAngola,NW&NEDRCongo,SWSouthSudan,W&SUganda,andWKenya.

H. c. bellieri De Vree, 1972 — SE Guinea, Liberia, S Ivory Coast, and S Ghana.

Descriptive notes. Head-body c¢.43-52 mm, tail 25-32 mm, ear 9-13 mm, hindfoot 5-3-7-5 mm, forearm 28-33 mm; weight 4-8 g. Pelage of the Broad-headed Pipistrelle is soft and dense; dorsally dark brown or reddish brown in crassulus, medium to dark chocolate-brown in bellier: (hairs are unicolored); ventrally either the same as dorsum (hairs unicolored; crassulus) or various shades of pale brown such as pale fawn and pale grayish fawn (hairs bicolored with medium to dark brown bases and pale tips; bellier:). Throat ofbellier: is usually paler, contrasting with ventral pelage but is the same as venter in crassulus . Ears are blackish ( crassulus) or dark brown (bellieri) and broadly rounded; tragus is slightly less than one-half the ear height, being broadest at midpoint in bellieri and broadest at base of anterior margin in crassulus, and is smoothly convex on posterior margin with small basal lobe and rounded tip. Tail of crassulus is longer than in bellieri. Membranes are blackish brown ( crassulus) or dark brown (bellieri). Penis is very long compared to other pipistrelle-like bats. Baculum ( crassulus) is very long and slender with rounded tip and very small basal lobes in line with extended shaft in vertical plane. Skull is moderately robust; braincase is broad and rounded, low in crassulus and high in belliers; interorbital region is relatively broad; rostrum is moderately long and relatively broad; forehead is almost straight to weakly concave; sagittal and lambdoidal crests are weakly developed and form weak occipital helmet in bellieri but not crassulus . I is deeply bicuspid and very broad and robust; I’ is unicuspid; P* is minute and displaced lingually from tooth row, and barely visible to invisible above gum (larger and more visible in bellieri); P* and C' are usually in contact in crassulus but separated in bellieri; lower incisors are tricuspid; and lower molars are myotodont. Chromosomal complement has 2n = 30 and FNa = 56 ( crassulus).

Habitat. Lowland rainforest, swamp forest, coastal forest, and montane forest at elevations of 70-1600 m. Nominate crassulus seems to prefer higher elevations of 800-1600 m, but can be found down to 300 m, whereas race bellier: appears to prefer rainforest at 70-600 m.

Food and Feeding. The Broad-headed Pipistrelle forages by slow hawking in cluttered habitats.

Breeding. In Ivory Coast, six pregnant females and one lactating female were found between late February and late March, four nulliparous females were captured between late August and late September, and a pregnant female was found in October. Scrotal males were found from late February to late March and in late August. Based on these data, the species may have more than one breeding season. Females produce single young.

Activity patterns. Broad-headed Pipistrelles are nocturnal.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red Lust (as Pipistrellus crassulus). Although rarely captured, the species appears to be widespread and locally common; e.g. in Tai National Park, Ivory Coast, where it was the most commonly captured pipistrelle-like bat.

Bibliography. ACR (2018), Bates et al. (2013), Decher et al. (2016), Fahr (2013z), Hayman (1954), Hayman et al. (1966), Heller et al. (1994), Monadjem & Fahr (2007, 2017b), Monadjem, Richards et al. (2013), Volleth et al. (2001), Weber & Fahr (2007a).