Pipistrellus hesperidus (Temminck, 1840)

Goodman, Steven M., Rakotondramanana, Claude Fabienne, Ramasindrazana, Beza, Kearney, Teresa, Monadjem, Ara, Schoeman, M. Corrie, Taylor, Peter J., Naughton, Kate & Appleton, Belinda, 2015, An integrative approach to characterize Malagasy bats of the subfamily Vespertilioninae Gray, 1821, with the description of a new species of Hypsugo, Zoological Journal of the Linnean Society 173 (4), pp. 988-1018 : 1004-1005

PIPISTRELLUS HESPERIDUS (TEMMINCK, 1840)

Molecular genetics

K2P distance within this lineage for animals obtained in dry forest habitats of western Madagascar was 0.001 (N = 14, Table 1); hence, these populations show little genetic variation at the nucleotide level. No haplotype was shared in common between sequenced samples of P. hesperidus from South Africa (TM 47666) and Swaziland (TM 47738), as compared to those from Madagascar (N = 28, Table 9). These lineages exhibited a divergence of 1.89% (K2P), reflecting 22 fixed mutations in the trimmed sequence. Haplotype diversity was reasonably high in the Malagasy population (Hd 0.744), in spite of a lower nucleotide diversity (Pi 0.00181), but these indices were not calculated for the African population due to limited sample size.

Morphometrics

Measurements presented in Table 2.

Craniodental morphology

Members of this genus are easily differentiated from known Malagasy members of the genus Neoromicia by the presence of five post-canine teeth as compared with four in the latter genus, which lacks a first upper premolar (P 3). Bates et al. (2006) noted that the upper canine (C 1) was not in contact with the second upper premolar (P 4). On the basis of specimens sequenced herein, this character holds, although in some cases these two teeth are almost in direct contact.

Bioacoustics

Measurements presented in Table 6.

Bacular morphology

As described by Bates et al. (2006) for Malagasy specimens of P. hesperidus , the baculum is relatively short (1.7–1.8 mm); here we add an additional four specimens that range in total length 1.60–2.10 mm ( Table 8). The distal tip and proximal base show a bifid indentation, and the shaft is distinctly recurved ( Fig. 8C ). This is the same configuration found in African P. hesperidus ( Fig. 8D ; Kearney et al., 2002), which ranges in total length from 1.7 to 2.5 mm (T. Kearney, unpublished data, N = 23).

Known geographical range

In Figure 1 , localities are presented of sequenced specimens of P. hesperidus , which also include the sites mentioned by Bates et al. (2006) for verified records of this species on Madagascar.

Taxonomic comments

Different lines of evidence, including karyological distinctions (e.g. Volleth et al., 2001), have been published indicating that P. hesperidus is most likely paraphyletic and best considered a species complex. However, because of a lack of resolution in character differences of holotypes representing different proposed names currently considered synonyms of P. hesperidus, Simmons (2005) recognised several subspecies, which include P. h. fuscatus Thomas, 1901 from much of the Afrotropics and P. h. subtilis Sundevall, 1846 from southern Africa and Madagascar. Greater genetic sampling is needed from southern Africa to resolve the differences found in the current study between this portion of the continent and Madagascar, but given the subtle genetic differences and seemingly continuous character states associated with bacular morphology, we maintain Malagasy populations as P. hesperidus .

Milne-Edwards (1881) described a small species of vespertilionid from Madagascar under the name Vespertilio humbloti . Peterson et al. (1995) mentioned that the type series was apparently lost and the status of this taxon could not be assessed. In the MNHN, the syntype series associated with Milne- Edwards’ description of V. humbloti was located (MNHN 1986.1074 to 1986.1082); most of the nine specimens were immature. Through the courtesy of Dr. Cécile Callou of the MNHN, the skulls from two adult specimens were extracted, cleaned, and allocated the numbers MNHN 1986.1074 and 1986.1075. Both of these specimens have a prominent first upper premolar (P 3), typical of the genera Pipistrellus and Hypsugo . Further, 1986.1074 has a seemingly bicuspid second upper incisor (I 3) and 1986.1075 an unicuspid I 3 that, in both cases, the longest portion of the I 3 reaches the length of the first upper incisor (I 2) cingulum; a diastema between C and second upper premolar (P 4), a prominent first upper premolar (P 3) in lateral view (similar to the illustration in Bates et al., 2006, Fig. 5B ); and craniodental measurements falling within the range of P. hesperidus ( Tables 3 and 4). On the basis of these different features, we identify the Milne-Edwards series of V. humbloti as P. hesperidus ; this awaits confirmation based on bacular structure or molecular genetics. Hence, V. humbloti is considered a junior synonym of P. hesperidus .

Two unsexed specimens held in the BMNH (28.1.24.1, 28.1.24.2) were collected by Capt. K. Parcon in June 1922 on Europa Island (22.3683°S, 40.3633°E) positioned halfway across the Mozambique Channel between Mozambique and Madagascar. Using the craniodental characters outlined in Bates et al. (2006) and Monadjem et al. (2010), the two animals are referable to Pipistrellus , and one of the specimens in relatively good shape (BMNH 28.1.24.2), based on the form of the first upper premolar (P 3) and the second upper incisor (I 3), as well as cranial shape, is identified as P. hesperidus and not Neoromicia nana , as written on the specimen label. This identification needs to be verified based on molecular data or potentially bacular morphology. In the same accession of the Pipistrellus material is a specimen of Coleura seychellensis Peters, 1868 (BMNH 28.1.24.3) obtained by the same captain on 4 October 1924 near Amirante Island, Seychelles (6.000°S, 53.1667°E), indicating that Capt. Parcon navigated boats in the western Indian Ocean. The context that the Pipistrellus specimens were obtained is ambiguous and they could have been stowaways on the vessel after docking in a coastal area and then transported to Europa Island; the direction of travel from Africa towards Madagascar or vice versa is unknown. However, if they represent a natural occurrence on Europa Island, this would provide evidence of movements for this species spanning at least half the distance between southern Africa and Madagascar.

Figures

Figure 1. Map of localities mentioned in text associated with sequenced members of the genera Neoromicia, Pipistrellus, and Hypsugo captured on Madagascar. Other localities mentioned in the text and an elevational gradient are also shown.

Figure 5. Echolocation calls of the holotype of Hypsugo bemainty sp. nov. (FMNH 217884), Neoromicia malagasyensis (FMNH 222724), Neoromicia matroka (FMNH 222727), Neoromicia robertsi (FMNH 222729), Pipistrellus hesperidus (FMNH 209270), and Pipistrellus raceyi (FMNH 217886).

Figure 8. Dorsal (above) and lateral (below) views of bacula from two species of Pipistrellus. A, Pipistrellus raceyi (FMNH 217886, total length 8.90 mm) from Kirindy Forest (CNFEREF); B, Pipistrellus raceyi (FMNH 222722, total length 6.10 mm) from near Andasibe; C, Pipistrellus hesperidus (FMNH 176094, average total length of four specimens 1.9 mm) from Parc National de Kirindy Mitea (redrawn from Bates et al., 2006, Fig. 10A); D, Pipistrellus hesperidus (FMNH 209270, total length 1.90 mm) from Grotte de Sarodrano; E, Pipistrellus hesperidus (FMNH 217905, total length 1.70 mm) from Grotte de Sarodrano; F: Pipistrellus hesperidus (TM 48624, UP-840, total length 2.18 mm) from South Africa.