Community and spatial distribution of bats (Chiroptera, Vespertilionidae) in the industrial city Yekaterinburg

Abstract

Bats have been living next to people for a long time, and they have successfully inhabited cities. Abundant information on the peculiarities of their ecology in urban conditions has been obtained for North America, Australia and Europe. Research of this problem for Russia is not numerous and is of interest. This paper presents information on the population of bats in the large industrial city of Yekaterinburg. The main aim is to study the species diversity and spatial distribution of bats, taking into account three factors that determine the quality of the animal habitat in the city (the presence of areas of woody vegetation and water-bodies as a feeding station; various buildings as suitable shelters). Yekaterinburg is located in Russia, close to the Asian-European border (56°50'N, 60°35'E.). Animals were observed and captured during the warm season using a mobile trap and a MAGENTA ELECTRONICS MK II ultrasonic detector (England). Museum materials (Yekaterinburg, Russia, Ural Federal University named after B.N.Yeltsin, Sverdlovsk Regional Museum, Institute of Plant and Animal Ecology UB RAS - IPAE 983653, IPAE 773780) were examined. The study was conducted according to the guidelines of international and national guidelines, and approved by the Ethics Commitee of IPAE UB RAS (protocol №11 29.04.2022). All captured animals were released into nature. Residents reported information about the distribution of animals (125 detection points of bats) for the period 2001-2020. For analysis, two zones of the built-up area of the city without forest parks were identified: zone I - the center and zone II - the remaining built-up part (See Fig. 1). To analyze spatial distribution, distances from the detection points of animals to the nearest squares, alleys, parks, forest parks, floodplain areas and city water-bodies of various sizes were calculated. In the vicinity of encounters and captures, urban buildings are described as sites of potential refuges (material, number of storeys). In total, more than 110 individuals of 5 species were counted during the surveys (See Table 1). The migratory species Vespertilio murinus, and sedentary species wintering in Ural caves - Eptesicus nils-sonii, Myotis daubentonii, M. dasycneme were found in zones I and II. M. brandtii (reported by V.E. Polyakov) was found in the forest-park zone. V. murinus is predominant, and E. nilssonii is the second largest. Both species were found in the city during the warm season (forming brood colonies) and, possibly, they overwinter in the city. Most of the bats were found near brick and panel 2-16-storey houses (See Fig. 2-a). In zone I, the detection points near older 2-6-storey buildings were significantly more frequent (х2 = 3.7; p < 0.05). In zone II, outside the center, the detection points of bats near 9-16 storey buildings were significantly more frequent = 6.4; p < 0.05). Most detections (81%) of bats in the city as a whole were observed in the immediate vicinity or at a distance of 200-500 m from large parks, boulevards, gardens, etc. (See Fig. 2-b). The frequency of detection of bats at a distance of more than 1 km from large plantations is significantly higher in zone II (7.6%, x2 = 8.9-10.1; p < 0.05). In relation to water-bodies, clear dependence in the location of animals was not found (See Fig. 2-c). Most often, bats use feeding stations near small areas of woody vegetation between residential buildings in yards and at a considerable distance from large water-bodies (72% of cases). At these feeding stations (zone I - center), the abundance of insects is lower than in their natural habitat (See Fig. 3). The spatial distribution of bats is associated with the quality of urban development and the presence of areas of woody vegetation, and does not depend on the presence of large water-bodies. It can be assumed that these distribution patterns of bats are due to the ecology of the background species V. murinus. The species diversity of the city's bats is reduced in comparison to their natural habitat (5 species out of 10 inhabit them). Similar reduction of bat species diversity is noted in other cities of Russia and Ukraine (See Table 2). It can be assumed that the low bat species diversity in Yekaterinburg is an indicator of the poor quality of urban greening.