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The population dynamics of the Tatra vole Microtus tatricus (Kratochvíl, 1952) (Arvicolinae, Rodentia) was monitored as part of a long-term study (1996–2008) of demography of small mammals conducted in Western Tatra Mountains—Roháče, Slovakia. We observed low abundance and population densities and a balanced sex ratio but slightly more frequent captures of females. Reproductively active Tatra voles were significantly larger and heavier than reproductively inactive voles. Reproduction in both sexes tended to begin in early spring, and females moved less than males. Individuals start to reproduce after overwintering. Spatial characteristics differed between sexes, with home range size, distance travelled, and observed range length being non-significantly greater in males than in females, suggesting greater male mobility. Females remained longer on the site than did males. Mature individuals of both sexes exhibited territoriality during the peak of breeding season in spring. Home range overlap occurred more often within females, and mainly in summer and autumn.
A field experiment was carried out in two types of forest environment — a relatively homogenous mixed coniferous forest with low plant species diversity and a reach and spatially differentiated alder wood. Spatial variation in activity of voles was sampled by placing ink pads and paper inside PVC waterpipes laid in a line on the forest floor. In the first stage of the experiment, use of space by bank volesClethrionomys glareolus (Schreber, 1780) was analysed without any bait in track collection tubes. In the second stage, we used an attractant in the form of scent collected from alien bank vole individuals of different sex (males, females), age (juveniles, adults) and physiological state (sexually active and not active). In the coniferous forest the distribution of number of visits in tracking tubes was of aggregated character both before and after providing odour of alien individuals. In the alder wood the aggregation level that had been initially lower than in the coniferous forest increased after providing scent. As a consequence, placing scent of alien individuals resulted in decreasing differences in animal distribution in both habitats. The results allow also to the supposition that the reaction to scent depends on sex, age, and the physiological state of the donor.
The paradigm regarding the ecology of populations of small rodents has had several basic theses: (1) the individual has a home range or is a migrant; (2) factors regulating population parameters (including density) include spatio-social relations between indi­viduals; and (3) the phenomena observed on trial plots with a system of live traps are the same as those beyond the plot. However, the home-range concept in small rodents is open to criticism in that: (1) observations point to much greater ranges of spatial activity in these animals than has been shown hitherto in plot-based studies with systems of live traps; (2) there is great variability in the directions and extent of the spatial activity of small rodents; (3) observations suggest that what is regarded as the area of spatial activity of an individual has limited information content since the "tenant" makes use of the area via tracks and trails along which it moves. Transfers of studies on odour-related information in small rodents from the laboratory to natural populations confirm the significance of odours in the life of these animals and in integrating their populations. It is possible that the need to leave information in the environment (informational conditioning) provokes considerable locomotory and spatial activity in small rodents. Live traps with bait (food) limit the spatial activity of animals. The set of traps in which an individual is caught thus represents not home range but trap range. A new paradigm for the ecology of small rodents should comprise the propositions that: (1) the function of olfactory information is the integration of a population into an ecological system; (2) the maintenance of odour-mediated condi­tioning in the environment is one of the reasons for locomotor and spatial activity; (3) the patchy distribution of food in the environment (including study plots with traps) gives rise to changes in the use made of space by individuals; (4) the phenomena observed on research plots with live traps containing bait are different to those ongoing at the same time outside these areas. Such a paradigm requires reinterpretation of research results obtained hitherto as well as the application of new research methods.
The response of coprophagous dung beetles Geotrupes stercorosus (Scriba, 1791) to the additional food supply in the habitat was examined, as well as their food preference, the effect of food and the daily rhythm of activity, and population density. The study was conducted in the summer and early autumn periods in four years (1998–2002) in a mixed coniferous forest Leucobryo-Pinetum (Matuszkiewicz, 1962) located in central Poland (52°20’N, 27°25’E). The insects were captured in baited traps functioning as Barber’s traps do. They were marked by clipping wing covers (based on the CMR technique). In total, about 31 000 individuals were caught and marked. It has been found that among faeces of different mammals, the faeces of forest rodents are the most attractive food for dung beetles. Food stimulates movements of beetles towards its source (foraging activity). The peak activity coincides with the afternoon hours (5.43 individuals per trap, on average, P ≤ 0.0001 as compared with the other periods of the day and night). There were years with a high number of captures (11.9 individuals per trap per day) and a low searching activity, and years with a low number of captures (5.06 individuals per trap per day) and a high searching activity. To compare differences in the number of beetles captured in pitfall traps with their genuine numbers in the habitat, the method of square sampling was used for evaluating their density (1.13 × 103 individuals per ha). There were days when the locomotor activity of the dung beetles was low and days when the number of captured beetles exceeded several times their genuine density on the area of 1 ha.
We hypothesized that the flight activity of bats in forests is higher in parts closer to edges due to the presence of species roosting in trees and foraging mostly outside as well as those coming to forage from outside. The aim of our study was to test this expectation using bat netting on roads in a forest belt 4–5 km wide in Kampinos National Park near Warsaw (central Poland). Tree stands were mostly coniferous. Ten full-night study sessions were done between the end of July and the beginning of September in the years 2007–2009. During each session, bats were netted at two sites situated in two zones designated as “edge” (100– 500 m from forest edge) and “interior” (1750–2250 m from forest edge). The study revealed twelve species, among which Eptesicus serotinus (Schreber), Nyctalus noctula (Schreber) and Barbastella barbastellus (Schreber) were by far most abundant. Total bat abundance recorded at ten pairs of netting sites differed significantly between the edge zone (ca. 2.5 times higher numbers) and the interior zone. Among individual species, a statistically important difference was shown only for Plecotus auritus (L.), which was more abundant close to the forest edge, though a similar tendency was noted in other species, mostly E. serotinus. The frequency of each species in the bat assemblage as well as species diversity of bats flying along forest roads did not differ between the two zones.
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