Summer chiropteran community in the Sergievka Park with the unique dominance of Pipistrellus nathusii on the northern periphery of its distribution range

Abstract

Listen

Translate article

The study of species on the periphery of their ranges is especially relevant for long-term research in protected areas. The aim of this study is to test the hypothesis that Pipistrellus nathusii on the northern periphery of its range has a clumped distribution with long-term viable breeding centres. The species composition and relative abundance of bats in the park were determined through capturing them with mist nets during the 1997–1998 and 2020–2022 survey periods. Within the 2nd survey period the use of an ultrasonic detector was additionally involved. Stability of the bat species composition in the protected area and a significant difference in the relative abundance between the surveys were revealed (χ2 = 47.31, p < 0.05). During both periods, the bat community in the park exhibited a pronounced dominance of P. nathusii and stable values of its relative abundance (40.7 and 44.2%, respectively). Perennial nursery colonies of Myotis daubentonii, Nyctalus noctula, and P. nathusii have been discovered in the park, which are arguably among the northernmost findings (59.89° N, 29.88° E) in European Russia. The catch rate (6.3 bats per net-night) and acoustic activity of the Chiroptera (16.6 active minutes per detector-hour) on the pond was significantly higher than on the alley and glade. This pattern is typical for all frequently recorded bat species – P. nathusii, N. noctula and Eptesicus nilssonii. According to the results of multiple analysis of variance, the effect of species on acoustic activity was the greatest (η = 24.59%, F = 15.52, p < 0.001). The impact of the habitat and the time since sunset, as well as the pairwise combined impact of these three factors, was also significant and reliable. The sizes of the nursery colonies were determined, which in P. nathusii were record high for the northern periphery of the breeding range, 212 individuals. Evening departures of P. nathusii from the nursery colony on the alley were characterized by their beginning before sunset, and from the nursery colony in the glade after sunset. The intensity of P. nathusii departure from the colony in the forest part of the park is significantly higher (5.3 bats/ min) than in the glade (1.4 bats/min). The fact that large nursery colonies of P. nathusii have existed for decades locally at 60° N latitude suggests the species may have a wider distribution in Eastern Fennoscandia in transformed areas containing old trees. Keywords: bats; South-Eastern Fennoscandia; relative abundance; nursery colonies; acoustic activity; circadian rhythms