New morphological and acoustic records of Myotis species (Mammalia: Chiroptera: Vespertilionidae) from northern Vietnam

Among the currently known bat species composition recorded from Vietnam, 12 species of Myotis distribute in the northern region: Myotis altarium, M. alticraniatus, M. annamiticus, M. annectans, M. chinensis, M. hasseltii, M. horsfieldii, M. indochinensis, M. laniger, M. montivagus, M. muricola và M. pilosus. Data on these Myotis species, particularly echolocation, is limited because almost all of them have been rarely recorded over the field surveys. Between 2020 and 2021, we conducted a series of bat surveys in northern Vietnam with an emphasis on Myotis species. Results from our studies included new data in morphology and echolocation of three species: Myotis alticraniatus, M. muricola and M. pilosus. External measurements of these species from Ha Long Bay are larger than those in previous publications. Their echolocation parameters (start frequency, end frequency, call duration) also differ from those in published descriptions. This paper provides new records of the three Myotis species from Ha Long Bay for further research, monitoring and conservation actions in the future.