Definition of roost and feeding sites of Northern bat (Eptesicus nilssonii) on Samarian Luka (Russia)
Is the most abundant species of bat in northern Eurasia. Research problems included identification of day shelters, feeding sites and nature of their use.
Approximately 11 distinct feeding sites were revealed. The most remote site is registered at a distance of 7 km.
Radiotracking on Eptesicus nilssonii on Samarian Luka (Russia): Definition of roost and feeding sites
1Smirnov D.G. 2Vekhnik V.P., 1Kurmaeva N.M.
1 Department of Zoology and Ecology, Penza State University, Lermontov 37, Penza 440026, Russiaeptesicus@mail.ru
2 Zhiguli preserve, p/o Bakhilova Polyana, Stavropolsky district, Samara Region, Zhigulyovsk 446351, Russia
Eptesicus nilssonii (Keyseling et Blasius, 1983) – a widespread specie in Eurasia. In the European part of Russia it occupies coniferous, mixed and partly deciduous forest from the north and midland where it is typical to find karstic relief forms (Ilyin, Smirnov, 2000). In the east of East European Plain the southern limit of distribution of the specie is at territory Samarian Luka (Samara region).
Here its largest hibernations are registered upon termination of which considerable part of individuals, without making distant migrations, dispersed in optimum biotopes for summer dwelling in direct proximity to places of hibernations. The maximum distance on which bats migrate after hibernations is 15 km (Smirnov, Vekhnik, 2012). Research problems included identification of day shelters, feeding sites and nature of their use.
Researches conducted in the north of Samarian Luka (the right coast of Volga).
For identification of summer shelters and feeding sites in May (8 days) and July (16 days), 2013 we carried out radio tracking of two adult females. Animals were caught by catching nets for bats. After measurement of the key morphological parameters small animals were equipped with TXA-001G (Telenax) radio transmitters weighing 0.42 g. It is lower than 5% of a threshold which is recommended for radio tracking of bats (Aldridge, Brigham, 1988). The mass of the body of traced bats, was 11.0 and 11.2 g. Radio transmitters were attached to the back part of animal body in area between shovels. Small animals were traced by means of the scanning receiver and Yagi-antennas during the whole time of activity. Trajectory of movement and day shelters were fixed on a schematic map. Battery life lasted as expected, providing 16 days of tracking. Radio signals in the conditions of the open district could be received at a distance of about 3–4 km, and in mountain and forest conditions the distance to traced animal made a max-imum of 1 km.
In the conditions of Samarian Luka the optimum habitats for E. nilssonii are the maple and lime trees of park type which grow on northern slopes of Zhiguli Hills.
During the summer adult females make colonies using from 3 to 5 shelters to settle down, as a rule, in hollows of lindens (80%) with a slit-like entrance at a height of 3 to 7 m from the earth.
Movement between the shelters happens in 2–4 days being at distance of 50–150 m from each other. The evening flight from shelters begins in 35-45 minutes after sunset. Some time after departure animals feed around the roost. At this time they fly under crowns. In 30-40 minutes after departure animals fly on other feeding sites which, most often, are near the Volga River. Approximately 11 distinct feeding sites were revealed, 6 from which are in limits of 50–800 m from shelters. The most remote site is registered at a distance of 7 km. For females it is peculiar that they use both single-phase, and two-phase night activity. Return to a shelter happens, most often, in three and a half hours after departure. The second departure is noted at 2.30 and proceeds for 20–30 minutes.
ACKNOWLEDGEMENTS The reported study was partially supported by RFBR, research project No. 11-04-00383 a. The study was partially supported by The Ministry of education and science of Russian Federation, project 14.В37.21.0204.
REFERENCES Aldridge H.D.J.N. and Brigham R. M., 1988. Load carrying and maneuverability in an insectivorous bat: a test of the 5% ‘rule’ of radiotelemetry. Journal of Mammalogy, 69: 379–382.
Iljin V.Yu. and Smirnov D.G., 2000. Specific features of distribution of resident bat species (Chiroptera: Vespertilionidae) in the eastern East Eurepean Plain and adjacent regions // Russian Journal of Ecology. 2000. Vol. 32. №2. P. 101–107
Smirnov D.G. and Vekhnik V.P. 2012. Features of spatial placement of sexual groups at Eptesicus nilssonii on Samarian Luka //Actual problems of a modern teriologica. Theses of reports of the All-Russian scientific conference. Novosibirsk: Sibregion Info. P. 134.
Telenax wishes to thank Dmitriy Smirnov for sharing this article