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1

Frequency and demographic parameters of white-tipped common dormice Muscardinus avellanarius

100%
Juskaitis R.
Acta Theriologica
|
2001
|
tom 46
|
nr 4
385-392
Out of 1154 marked common dormice Muscardinus avellanarius (Linnaeus, 1758), 219 animals (19.0%) had white tail tips at Vilkaraistis forest (Moletai district, east Lithuania) in 1984-1993. The extent of white tail-tip varied from a slight tuft to a notable 22 mm length of white hair in the tail tip. In this population white-tipped individuals represented, on average, 25.7% among juvenile females, 24.9% among adult females, 13.4% among juvenile males, and 15.7% among adult males. White-tipped females were significantly more frequent than males, both in juveniles and in adults. The share of white-tipped dormice fluctuated in different years from 12.5% to 25.6% among adult dormice, and from 9.2% to 28.3% among juveniles. The percentage of white-tipped dormice among juveniles in different years was directly proportional to population density in autumn. There was no clear difference or trend in the mortality rate in white-tipped versus normal dormice. The contribution of white-tipped females to population reproduction was relatively lower than that of normal females: only 18.4% out of all registered breeding cases (n = 212) were due to white-tipped females.
2

Summer mortality in the hazel dormouse (Muscardinus avellanarius) and its effect on population dynamics

100%
Juskaitis R.
Acta Theriologica
|
2014
|
tom 59
|
nr 2
In the period 2000–2012, 38.3 % of 950 marked overwintered hazel dormice (Muscardinus avellanarius) were not recaptured at a study site in Lithuania in autumn. As adult dormice are sedentary, it is presumed that those dormice not recaptured died between late April and August. The highest total number of dormice captured for the last time was recorded in May and the lowest in August. The total summer mortality was significantly higher in females (42.5 %) than in males (34.6 %), but it did not depend on dormouse age or body weight. Tawny owl (Strix aluco) is the main known dormouse predator in Lithuania, and likely, it has the highest impact on summer mortality of M. avellanarius. Over the years, the total summer mortality of adult dormice ranged from 27 % to 52 %. The increased summer mortality resulted in decreased total dormouse population density and particularly decreased density of adult females in summer. Decreased densities led to more intensive breeding in the dormouse population, specifically breeding by young-of-the-year females, a pattern that is not common for this species. The number of breeding cases by young-of-the-year females was inversely related to the density of adult overwintered females in summer and to the number of breeding cases of these females. Breeding by young-of-the-year females was the main factor in the restoration of decreased population density in summer. Lithuanian populations of M. avellanarius are unique in their high proportion of breeding cases by young-of-the-year females amongst all populations investigated in the entire species distributional range.
3

Ranging and movement of the Common dormouse Muscardinus avellanarius in Lithuania

100%
Juskaitis R.
Acta Theriologica
|
1997
|
tom 42
|
nr 2
Adult Muscardinus avellanarius (Linnaeus, 1758) were found to be sedentary, showing small home ranges. The mean range area for males (n = 46) throughout their active season was 1.0 ± 0.05 ha, whereas for females (n = 33) it was 0.8 ± 0.05 ha. Male home ranges partially overlapped those of females and each other, whereas female home ranges hardly ever overlapped. In separate years adult dormice were sometimes found to change their home ranges. Dispersal was a necessary stage in the life of the young. The mean distance travelled from the birth place by young born in May-July (it = 65) was 360 ± 30 m, whereas the distance travelled by young born in August-September (n = 109) was 130 ± 10 m. The greatest travelled distance was 1200 m. About 90% of the young that survived the first winter became sedentary in the first autumn of their life, the remainder during the following spring.
4

The influence of high nestbox density on the common dormouse Muscardinus avellanarius population

100%
Juskaitis R.
Acta Theriologica
|
2005
|
tom 50
|
nr 1
The response of common dormouseMuscardinus avellanarius Linnaeus, 1758 population to availability of nest sites was studied by manipulating the nestbox grid and ring-marking dormice. Abundance of adult dormice more than doubled in the 25 × 25 m nestbox grid in comparison to the 50 × 50 m grid, as a result of increased nestbox density from four to 16 boxes/ha. This effect already became apparent in the first year after additional nestboxes were made available and resulted from dormouse immigration, mostly from adjacent areas without nestboxes. In the second and third years, the number of two-year-old and older resident dormice, which had their home ranges in this plot, increased considerably. The average size of dormouse home range decreased by approximately half both in males and females in the 25 × 25 m grid compared to the 50 × 50 m grid. The proportion of breeding adult females did not differ between the two grids in spite of different adult dormouse density. Shortage of secure nest sites was a limiting factor for the common dormouse population abundance in the forest where natural tree hollows were absent, and high nestbox density increased environmental carrying capacity.
5

Nestbox grids in population studies of the common dormouse [Muscardinus avellanarius L.]: methodological aspects

100%
Juskaitis R.
Polish Journal of Ecology
|
2006
|
tom 54
|
nr 3
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 lowdensity 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 × 25 m and 50 × 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 × 25 m and 50 × 50 m grids. Regular control of nestboxes placed in the 25 × 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 × 50 m grid. However the 25 × 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 × 20 m, 25 × 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.
6

Life tables for the common dormouse Muscardinus avellanarius in Lithuania

100%
Juskaitis R.
Acta Theriologica
|
1999
|
tom 44
|
nr 4
Life tables for two populations of the common dormouse Muscardinus avellanarius (Linnaeus, 1758) are presented. The mortality rates qx of the common dormouse appeared to be relatively constant and did not follow a typically mammalian "U" shaped curve with age. Mortality rates increased evenly with age both in females and males, in both populations, whereas a decrease in qx was observed only among males in their third year of life. Specific characteristics of the qx curve for the common dormouse include the relative longevity of this small rodent, and rather constant mortality during hibernation in all years of life.
7

Harvest mice Micromys minutus and common dormice Muscardinus avellanarius live sympatric in woodland habitat

63%
Juskaitis R., Remeisis R.
Acta Theriologica
|
2007
|
tom 52
|
nr 4
349-354
In an overgrown clearing, which occupied an area of 5 ha within mixed spruce-deciduous forest, 106 and 20 nests of the harvest mouseMicromys minutus (Pallas, 1771) and 81 and 59 nests of the common dormouseMuscardinus avellanarius (Linnaeus, 1758) were recorded in the fourth and fifth years after clear-felling, respectively. The highest densities of nests ofM. minutus andM. avellanarius were 46 nests/ha and 39 nests/ha, respectively, in two different plots. The affinity betweenM. minutus andM. avellanarius was negative in overgrown clearings according to the distribution of their nests. Such a result was expected becauseM. minutus andM. avellanarius used different nest supporting plants:M. minutus used tall grasses, whileM. avellanarius used young trees and shrubs. However, no positive relationship was found between the number of nests ofM. minutus and cover of grass vegetation in plots with the highest density of nests ofM. minutus. Most nests ofM. Minutus were situated in areas covered by young trees among which tall grasses, mainlyCalamagrostis epigeios, grew, often on the borders with the areas covered by grass vegetation. The successionary stage when woody vegetation reached 4–5 years old did not choke grass vegetation yet was favourable for bothM. minutus andM. avellanarius in overgrowing clearings.
8

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

63%
Juskaitis R., Remeisis R.
Polish Journal of Ecology
|
2007
|
tom 55
|
nr 4
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 overgrown 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 nests 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 tress (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 ± 0.6 m above ground in young woodlands, and it was related to the age and height of young trees and shrubs.
9

Diet of the fat dormouse (Glis glis) on the northern periphery of its distributional range

51%
Juskaitis R., Baltrunaite L., Augute V.
Acta Theriologica
|
2015
|
tom 60
|
nr 2
We studied the seasonal and annual variation in diet composition of the fat dormouse (Glis glis) in Lithuania, a locality situated on the northern periphery of the dormouse range and outside of the range of the European beech (Fagus sylvatica). After emergence from hibernation, dormice fed on oak acorns (from the previous year), inflorescences of various trees, vegetative parts of plants and food of animal origin (birds, their eggs and insects). In June, soft mast and seeds of birches supplemented the dormouse diet, and diet composition was the most diverse during this period. In July, raspberries and fruits of glossy buckthorn constituted the bulk of dormouse diet, but seeds of birches dominated in a specific year. Hard mast (mainly acorns) dominated the diet of G. glis from August until the beginning of hibernation in October. A high prevalence of acorns, comparatively high proportion of birch seeds and low proportion of food of animal origin in the diet, as well as feeding on fruits of glossy buckthorn, are specific features of feeding by G. glis in Lithuania. The diet of G. glis on the northern periphery of its range resembles its diet on the eastern periphery of the range where beech trees are also absent. According to the composition of G. glis diet, feeding conditions in both of these peripheral regions are poorer in comparison to central or southern regions.
10

Nest site preference of forest dormouse Dryomys nitedula (Pallas) in the north-western corner of the distribution range

51%
Juskaitis R., Balciauskas L., Siozinyte V.
Polish Journal of Ecology
|
2012
|
tom 60
|
nr 4
Lithuania is situated in the very north-western corner of the large distribution range of the forest dormouse Dryomys nitedula and it might be considered that dormouse habitats should be both different and sub-optimal in this area in comparison to central parts of the range. The aims of the present study were to analyse which vegetation parameters determine nest site preference of D. nitedula and to compare these with nest site preferences of other dormouse species. The population of D. nitedula was studied from 2001 to 2011 using nestboxes set up in a grid system, with regular control of the nestboxes and ringing of dormice captured. During entire study period, 97 individuals were marked with rings and the total number of dormouse captures was 440. Vegetation parameters (the composition of the overstorey and understorey, the numbers and cover of different tree and shrub species, absence of vegetation etc.) were evaluated quantitatively in areas of 2500 m2 around 58 nestboxes at this study site. During the period 2001–2002, the abundance of D. nitedula was relatively high, with the dormice using the entire area of the study site, showing a preference for nest sites with a more diverse overstorey and understorey. However, no significant correlations were found between indices of nestbox use and other vegetation parameters in this period. During the period 2003–2011, when the dormouse abundance was lower but stable, dormice used only part of the study site area, in this preferring nest sites with a better developed and diverse understorey (especially with young rowan, lime and aspen trees), with more abundant mature oak, lime and black alder trees and a higher percentage of raspberry and bramble cover, as well as overgrown clearings. D. nitedula avoided nest sites with higher total number of mature trees (especially Scotch pine and Norway spruce), as well as areas with higher percentage of bilberry cover and open areas (rides, presence of stumps). In general, a well-developed and diverse understorey was the main habitat component which determined nest site preference of D. nitedula in the very northwestern corner of its range. Thus, D. nitedula retains its main habitat requirement which is characteristic also for other parts of its large range. Vegetation parameters determining nest site preference of D. nitedula are rather similar to nest site preference of the common dormouse Muscardinus avellanarius. However, D. nitedula may live in less rich habitats probably because their diet includes more food of animal origin.
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