On the Fauna and Ecology of Bats in Central Yakutia
The paper presents the results of the study of bats in Central Yakutia conducted in 2014-2015. The study included observations and live capture. In total, 42 bats were examined and then released in places where they had been captured. Echolocation calls were detected by means of an ultrasonic detector The Magenta «Bat 4» and were recorded on a digital voice recorder. The oscillograms were analysed in Cool Edit Pro 2.1 software environment. According to preliminary data, in the studied area, eastern water bat Myotis petax prevailed (69.0%), while Siberian bat M. sibiricus ranked the second place (29.0%). Ognev's long-eared bat Plecotus ognevi was represented only by one specimen (2.0%). Myotis petax was larger as compared to M. sibiricus. The females of Myotis genus were larger than the males. The sex structure of bat population in the studied area was strongly shifted to predomination of females, most likely due to the presence of maternity colonies there. The activity of mouse-eared bats started with twilights and lasted 4.0 hours in June, 4.5 hours in July, and 3.0 hours in August in average. The duration of bats' activity depended on insect activity which was determined by weather conditions. The fauna of ectoparasites in the studied bats comprised 8 species of mites and insects. The Parasitic Frequency Index (PFI) ranged from 53.3% (flea Myodopsylla trisellis) to 6.7% (flea Ischnopsyllus hexactenus). The highest Parasitic Abundance Index (PAI) was recorded for gamasid mites (5.0 per a host in average). During hunting, bats emitted four basic types of echolocation calls. The signals were clearly detected within the frequency range from 15 to 50 kHz.