Myotis formosus ( Hodgson, 1835 )

Ruedi, Manuel, Csorba, Gábor, Lin, Liang- Kong & Chou, Cheng-Han, 2015, Molecular phylogeny and morphological revision of Myotis bats (Chiroptera: Vespertilionidae) from Taiwan and adjacent China, Zootaxa 3920 (1), pp. 301-342 : 334-335

Myotis formosus ( Hodgson, 1835)

Synonymy. Vespertilio formosa Hodgson, 1835 . Type locality Kathmandu Valley, Nepal.

Kerivoula pallida Blyth, 1863 . Type locality Chaibassa, Orissa, India.

Vespertilio auratus Dobson, 1871 . Type locality Darjeeling, West Bengal, India.

Vespertilio dobsoni Anderson, 1881 . Type locality Purnia, Bihar, India. Not V. dobsoni Trouessart, 1878 .

Vespertilio Andersoni Trouessart, 1897 . Replacement name for Vespertilio dobsoni Anderson, 1881 , preoccupied by V. dobsoni Trouessart, 1878 .

Myotis formosus: Tate 1941 . First use of current name combination.

Myotis flavus Shamel, 1944 . Type locality Yuanli, Miaoli, Taiwan.

Myotis formosus formosus: Koopman 1994 . Name combination.

Myotis formosus watasei: Lin et al. 1997 . Name combination.

Myotis flavus: Lin et al. 2004 . Name combination.

Myotis formosus flavus: Cheng et al. 2010 . Name combination.

Myotis flavus: Jiang et al. 2010 . Name combination.

Myotis formosus flavus: Ruedi et al. 2013 . Name combination.

Taxonomic remarks. A full taxonomic treatment of species from the subgenus Chrysopteron (to which M. formosus belongs) has been published recently ( Csorba et al. 2014). To avoid repetitions, we outline hereafter only the main distinguishing characters of the two species living in Taiwan and China ( M. formosus and M. rufoniger ). All species classified in this subgenus are phylogenetically part of the Ethiopian Clade ( Csorba et al. 2014) and constitute a robust, monophyletic clade ( Fig. 3). Following Csorba et al. (2014), the population of Taiwan (being significantly larger than their continental counterparts) is considered here as a distinct subspecies, M. formosus flavus .

Distribution. M. formosus is a rare, but relatively widespread species, found from Afghanistan, along the foothills of the Himalaya ( Csorba et al. 2014) east to Jiangxi province in China ( Jiang et al. 2010), and Taiwan.

Measurements. See Table 4 for measurements of the Taiwanese subspecies, M. f. flavus . Measurements for the nominal subspecies are given in Csorba et al. (2014).

External morphology. This spectacular, relatively large Myotis has a unique cottony and yellowish fur, both above and below, the dorsal parts being only slightly darker at the hair tips (i.e., no ”smoked” aspect of fur as in M. rufoniger ). The wing membranes are parti-colored, with a characteristic orange (along bones) and black patterning (see pictures in Lin et al. 2004). The uropatagium is essentially orange, as are the ears (unlike in M. rufoniger , which has conspicuous black margins to the ears) and face. Thumbs and hairy feet are also largely orange, except close to the claws, which are strong and black. Wings are attached to the base of the outer toe.

Skull morphology. The skull is large, with massive canines and strong molars. The second upper premolar is much smaller, less than half the size of the first, and is usually completely displaced lingually from toothrow and thus invisible in side view ( Fig. 8 c). The posterior parts of the braincase are high and globose, with very weak or no occipital or lambdoid crests (unlike in M. rufoniger , which has a more angular skull and marked crests).

Natural History. This beautiful, but rare bat is known from few specimens, and owing to its large distribution across Asia is likely to have different ecologies throughout its range. In Taiwan, it is found exclusively in the lowlands, where it roosts either among tree foliage ( Swinhoe 1870; Chen et al. 2010), or in buildings ( Lin et al. 2004). In both situations, the bats are fully exposed to the light and seem to rely on their particular coloration to avoid predation. They occupy the breeding colonies (which may number up to several hundred individuals) between March and July. In October, they disappear from the breeding colonies to hibernate in unknown winter roosts.

Figures

FIGURE 8. Lateral and dorsal views of skull, and mandible of (a) Myotis soror sp. n. (HNHM 2003.36. 20., holotype), (b) M. frater (TESRI B 0283), (c) M. formosus (THUMB 65), and (d) M. rufoniger (THUMB 30022). All specimens are from Taiwan. Scale = 10 mm.