Trappability of bank vole in pitfalls and live traps

Abstract

Studies were made in an isolated natural population ofClethrionomys glareolus of the trappability of different age groups of individuals, using either live traps or pitfalls, or both kinds of traps simultaneously. Trappability of bank voles in pitfalls is lower than in live traps. The older the group, the higher the trappability of different groups of individuals in live traps, whereas trappability in pitfalls does not exhibit such differentiation. When live traps and pitfalls are used together differentiation of trappability in live traps is the same as when these traps are used on their own. Trappability in live traps increases with the age of individuals, while that in pitfalls decreases. Individuals introduced into the population are characterized, regardless of their age, by trappability similar to that of the group of youngest individuals in the population. As the age group grows older differences in trappability increase among its members. It was found that an individual's weight does not determine its trappability. The results obtained are in agreement with G 1 i w i c z's hypothesis (1970) suggesting that the trappability of different age groups is due to the social organization of the population.

Supplementary food and the winter dynamics of bank vole populations

“…Hence 309 individuals actually trapped in January plus 60 individuals not trapped in January but trapped in April, plus 60 individuals which did not survive between January and April (a 50°/o mortality at that time) but which were probably still alive in January, gives a total number of 429 individuals living on the island in January. and the spring number from 29 to 70 individuals (Andrzejewski & Rajska, 1972). Under the effect of an experimental increase in the food supply significant changes in these dynamics were observed.…”

“…The first one an island 4 ha in area situated in a lake in northern Poland (53°40'N, 21°35'E). The vole population living there had already been subjected to numerous analyses (B u j a 1 s k a, Bujalska, 1970Bujalska, , 1971Mazurkiewicz, 1971Mazurkiewicz, , 1972Andrzejewski & Rajska, 1972, and others).…”

A comparison of the effectiveness of pitfall and longworth live-trapping techniques in population studies of house mice

“…In contrast, in a population study of Microtus pennsylvanicus (Ord, 1815) Longworths were found to be more effective than pitfalls, although first capture of young voles occurred more often in pitfalls (Boonstra & Rodd, 1984). Andrzejewski & Rajska (1972) found live-traps (dimensions 160X100X X100 mm, see Olszewski, 1968) more effective than pitfalls in capturing Clethrionomys glareolus (Schreber, 1780); and although the trappability [245] in the former increased with age of bank voles, that in the latter was low across all age classes. It is clear from these studies that a response to a particular trapping method cannot be extrapolated across species.…”

Management of amphibians, reptiles, and small mammals in North America: Proceedings of the symposium

“…Several studies that compared various types s f pitfalls and live-traps (also called box-or cage-traps) in the field (Chclkowska 1967, &x>nstra and Krebs 1978, Peterson 1980, Boonstra and Rodd 1984 Guy nn 1987) found the sampling efficiency of the two methods varied considerably (Andrzejewski and Rajska 1972, Briese and Smith 1974, Cockburn eh a!. 1979, Williams and Braun 1983.…”

“…Still, trapping remains the most practical method for assessing small mammal populations (Williams and Braun 3983). Because responses to trapping methods may differ, even within the same species (Andrzejewski and Rajska 1972), diverse sampling schemes might reveal population dynamics and community structure more completely than any single method (Weia-ter andSmith 1972, Bmnstsa andKaebs 1978).…”