Myotis hasselti, Temminck, 1840

Bates, Paul J. J., Nwe, Tin, Bu, Si Si Hla, Mie, Khin Mie, Swe, Khin Maung, Nyo, Nyo, Khaing, Aye Aye, Aye, Nu Nu, Toke, Yin Yin, Aung, Naing Naing, Thi, Mar Mar & Mackie, Iain, 2005, A review of the genera Myotis, Ia, Pipistrellus, Hypsugo, and Arielulus (Chiroptera: Vespertilionidae) from Myanmar (Burma), including three species new to the country, Acta Chiropterologica 7 (2), pp. 205-236 : 216

Myotis hasselti

Van Hasselt’s Bat

Vespertilio hasseltii Temminck, 1840: 225 ; Bantam, Java

New material from Myanmar

Yangon Division: Yangon City, -.8.2003, 1 ♂ (RL1) and -.10.2000, 1 ♂ (Y87).

Previous records from Myanmar

Yangon Division: Yangon City (BMNH collection); Rakhine State: Ponnagyun Township ( Pearch et al., 2003); Tanintharyi Division: Myeik (= Mergui, Lindsay, 1926).

Descriptive characters

A medium sized species of Myotis with a forearm length of 41.6 mm based on a single specimen from Myanmar ( Table 4; FA = 37.2–40.3 mm in Bates and Harrison, 1997; 38.8–39.1 mm in Bates et al., 1999). The feet are large; they exceed half the length of the tibiae. The wings are attached to the ankles or the tibiae. The dorsal pelage is dark brown with the hair tips slight ly paler than the roots. On the ventral sur- face, the tips are grey and the roots darker. The skull has a bulbous braincase. The sec- ond upper premolar (P3) is minute or sometimes absent; if present, it is usually about one quarter the crown area of the first (P2) and is displaced internally. The lower ca- nine (C1) considerably exceeds the third lower premolar (P4) in height. The second lower premolar (P3) is about one third the crown area and height of the first (P2); it is in the toothrow or displaced internally.

Similar species

Myotis hasselti is distinguished from M. horsfieldi by its larger size and by the attachment of the wing. In M. hasselti , it is attached to the ankle or tibia whilst in M. horsfieldii it is attached to the outer metatarsal of each foot.

Ecological notes

Previously collected from the gardens of the British Embassy residency in Yan- gon (BMNH specimen), more recently M. hasselti was seen flying over the Kan- dawmin and Kandawgyi lakes in cen- tral Yangon city. In both these latter sites, they roosted under bridges. At Kandaw- gyi Lake, about 20 individuals were ob- served flying close to the shore of a small island. At the time, it was assumed that they were hawking for insects just above the water surface as this behaviour has been observed elsewhere, including Sri Lanka ( Phillips, 1980) and Malaysia ( Medway, 1969). A subsequent analysis of the stomach contents of one individual found evidence of piscovory, with fish scales (Dr Khin Mie Mie, pers. comm.). In Ponnagyun township in northern Rakhine, a small colony was found roosting in an electrical metre box in an office. The township is situated on a level plain, with some sandy ridges. It is bounded by the sea, the Kala- dan River and series of low hills. Myotis hasselti is also known from Tanintharyi, for a description of the area see M. muricola above.