Hypsugo crassulus (Thomas, 1904)

Bates, Paul J. J., Cameron, Kenneth, Pearch, Malcolm J. & Hayes, Benjamin, 2013, A review of the bats (Chiroptera) of the Republic of Congo, including eight species new to the country, Acta Chiropterologica 15 (2), pp. 313-340 : 325

Hypsugo crassulus (Thomas, 1904)

Broad-headed pipistrelle

Pipistrellus crassulus Thomas, 1904: 206 ; Efulen, Cameroons (= Cameroon).

New material

HZM.1.40190 , ♂, 4 August, 2012, Forest Trails, Lekoumou , 2°45.767’S, 13°36.365’E . This is the first authenticated record for Congo ( Appendix I ). According to Happold and Happold (2013), this species is widely distributed but localised in Africa, not uncommon in suitable habitats.

Description

A small, nondescript, species with a short forearm length of 26.7 mm ( Table 2 ) but a robust body. The dorsal pelage, wing and interfemoral membranes are dark. The ventral pelage appears to be dark. In the ear, the tragus is tall and relatively narrow; the anterior border is straight, the posterior border is rounded and there is a well developed basal lobule ( Fig. 8C ). The skull has a greatest length of 13.80 mm ( Table 3 ). In lateral profile, the rostrum runs smoothly to the braincase with only the slightest indication of a concavity in the interorbital region; the braincase is relatively flat and is highest at its most posterior point ( Fig. 10A ). The first upper incisor (I 2) is tricuspid; the second (I 3) is unicuspid but with a well developed cingulum, it attains half the height of I 2 ( Fig. 10A ). The first upper premolar (P 2) is minute and displaced internally such that the canine and second premolar (P 4) are nearly in contact ( Fig. 10A ). The first lower premolar (P 2) is between half and two-thirds the crown area and two-thirds the height of the second (P 4) ( Fig. 10A ). The baculum, which is 3.9 mm in length, has a long, thin, pointed shaft, which is curved when viewed laterally, and a bilobate base ( Fig. 11A ); this compares well with the baculum of the holotype of crassulus illustrated in Hill and Harrison (1987: Figure 7e ).

Taxonomic notes

Currently there are no subspecies recognised ( Heller et al., 1994; Happold and Happold, 2013).

Figures

APPENDIX I A list of the forty-three bat species currently recorded from Congo, including citations in the literature and locality data. CS (Conservation status – NT: Near threatened; DD: Data deficient; LC: Least concern) is based on IUCN Red List of Threatened Species retrieved on 8 May, 2013. Two species listed here have not been assessed (na) by IUCN for their conservation status but rather have been included within other taxa: Triaenops afer in Triaenops persicus and Chaerephon leucogaster in Tadarida pumila. Superscripts associated with localities in column 4 refer to the superscripts for the literature cited in column 3

FIG. 8. Right tragus of (A): Glauconycteris alboguttata, HZM.1.40172, ♀; (B): G. beatrix, HZM.1.40181, ♀; (C): Hypsugo crassulus, HZM.1.40190, ♂; (D): Neoromicia brunnea, HZM.1.40191, ♂; (E): N. nana, HZM.321.40186, ♂; (F): N. tenuipinnis, HZM.7.40170, ♀; (G): Pipistrellus nanulus, HZM.1.40189, ♂; (H): Mimetillus moloneyi, HZM.10.40177, ♂; (I): Miniopterus inflatus, HZM.19.40182, ♂. Scale = 2 mm

FIG. 10. Skulls of three small vespertilionids, including lateral view of right upper incisors and occlusal view of left mandibular dentition (left) and left maxillary dentition (right) of (A): Hypsugo crassulus, HZM.1.40190, ♂; (B): Mimetillus moloneyi, HZM.10.40177, ♂ and (C) Pipistrellus nanulus, HZM.1.40189, ♂. Scales for skulls and occlusal views of toothrows (left and right) = 2 mm; scale for upper incisors (centre) = 1 mm

FIG. 11. Bacula of four pipistrelles. (A): Hypsugo crassulus, HZM.1.40190; (B): Neoromicia brunnea, HZM.1.40191; (C): N. nana, HZM.321.40186; and (D): Pipistrellus nanulus, HZM.1.40189. Scale = 1 mm

FIG. 7. Nycteris hispida, HZM.52.40188. (A): Anterior, left mandible; (B): left, upper incisors and canine; (C): right tragus; (D): baculum (dorsal view [left] and lateral view [right]). Scales for A, B, and D = 1 mm; scale for C = 2 mm