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Summer nest sites of the common dormouse Muscardinus avellanarius L. in young woodlands of Lithuania

Juskaitis R., Remeisis R.

Polish Journal of Ecology

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2007

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Vol. 55, nr 4

795-803

EN

Selection of nest sites by the common dormouse Muscardinus avellanarius L. depends on habitat type and suitable plants that can support and hide dormouse nests properly. Lithuania is situated in the northern part of the distribution rage of M. avellanarius. Some peculiarities of nest site selection in these dormice could be expected here compared to the regions situated further south because of differences in composition of the woody vegetation. Searches for nests of M. avellanarius were carried out in different young woodlands of Lithuania at 16 study sites, and detailed study of nest site selection in this species was carried out in an over-grown clearing in 2005-2006. In comparison to other parts of its distribution range, significant prevalence of Norway spruce as a nest supporting plant was observed in Lithuania. More than 70% of nest of M. avellanarius (n = 120) found in different young woodlands were situated in young spruce trees. In habitats where suitable spruce trees were absent or scarce, young deciduous trees (e.g. oak, ash, aspen, lime, hornbeam) and shrubs (e.g. hazel, bramble, raspberry, willow, honeysuckle) were selected for nesting sites. In overgrown mid-forest clearing, young spruce trees were evidently preferred by M. avellanarius as nest supporting plants despite their comparatively scarcity. Planted oak trees were selected by M. avellanarius for nesting in the plot of the clearing where young spruce trees were almost absent. The average height of dormouse nests was 1.0 [plus or minus] 0.6 m above ground in young woodlands, and it was related to the age and height of young trees and shrubs.

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Nestbox grids in population studies of theCommon dormouse (Muscardinus avellanarius L.): methodological aspects

Juskaitis Rimvydas

Polish Journal of Ecology

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2006

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Vol. 54, nr 3

351-358

EN

Two different nestbox grids have been used for studies of the common dormouse (Muscardinus avellanarius L.) populations: high-density nestbox grids in small plots (e.g. 25-30 boxes ha^-1 in 1 ha plots) and low-density nestbox grids in large plots (e.g. 4 boxes ha^-1 in areas of 60 and 85 ha). The present study aimed to compare efficiency and suitability of 25 x 25 m and 50 x 50 m nestbox grids for studies of the common dormouse population, and to show limitations of small study plots in dormouse studies. Live trapping of dormice within nestbox grids proved that all dormice captured used nestboxes placed in both 25 x 25 m and 50 x 50 m grids. Regular control of nestboxes placed in the 25 x 25 m grid gave an opportunity to register all adult dormice living in the study site during shorter periods, and average dormouse capture rate was significantly higher compared to the 50 x 50 m grid. However the 25 x 25 m nestbox grid had one substantial drawback: high nestbox density (16 boxes ha^-1) increased environment carrying capacity for dormice in the forest, where natural hollows were almost absent. In consequence, adult dormouse density increased two to four-fold, while their home range sizes decreased by about half. Dormice are distributed irregularly in large forest areas, and the results obtained in small study plots may not reflect the average characteristics of the population. Some results obtained in small study plots (e.g. density, mortality) can be overestimated because of dormouse movements and edge effects. Predators, e.g. owls, can catch some dormice and substantially influence the results obtained in small plots. Because of the influence on dormouse population density and other population parameters, high density nestbox grids (e.g. 20 x 20 m, 25 x 25 m) should not be used in dormouse population studies. Small study plots (e.g. 1 ha) are completely unsuitable for estimation of such dormouse population characteristics as survival (mortality) and dispersal.

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Nest material of the common dormouse(Muscardinus avellanarius L.) used in nestboxes,Podilla (West Ukraine)

Zaytseva Hanna

Polish Journal of Ecology

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2006

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Vol. 54, nr 3

397-401

EN

The common dormouse Muscardinus avellanarius L is a regular inhabitant of the nestboxes placed in the region of Podilla (48 degrees 20'N 26 degrees 30'E), West Ukraine. One hundred and forty seven nestboxes were controlled during 2004. The dormouse occupied 31% of the nestboxes available in oak-hornbeam forest. It is a significant competitor of birds, which frequently occupies the nests of the collared flycatcher Ficedula albicollis Temminck, great tit Parus major L. and blue tit Parus caeruleus L. At the end of the year 41 nests of M. avellanarius from the nestboxes were studied and the nest material was analysed quantitatively. We found four basic types of dormouse nests: foliar, mixed, layered and grassy. Mixed nests (54%) were the most frequent. Dormice preferred to build mixed nests on the flycatcher nests, and foliar nests on the tit nests. Leaves of trees constituted the greatest part of the nest material (62%). Leaves of hornbeam were the commonest fraction of the nest material, but those of linden, oak and maples were also present in smaller quantities. Simultaneously an experiment on the use of an artificial material for nest building by forest inhabitants was carried out in the nature reserve. Dormice also used an artificial material; namely a coloured thread and some tow were found in six nests on the study area. M. avellanarius showed high plasticity and used the most widespread and accessible nest materials available in the particular habitat.