Geographically peripheral populations are likely to experience suboptimal conditions, and several population characteristics may be influenced. The aim of the present study was to assess characteristics of the populations of hazel, forest and fat dormice on the northern periphery of their ranges in continental Europe in comparison to populations situated in the rest of their ranges. The dormouse populations analysed were found to be distinct from other populations in many aspects of their ecology. On this northern periphery of the ranges, the dormouse activity season is shorter and ends earlier. The population density is also lower, but inter-annual abundance dynamics are comparatively stable. Except the shorter breeding season however, there is no clear general pattern regarding other aspects of reproduction. The composition of the vegetable food used by dormice is rather specific. Contrary to expectations, the proportion of food of animal origin is not increased in the dormouse diets. The main habitat requirements of dormice are similar to those in other parts of their ranges, though the composition of woody plant species in the dormouse habitats is different. Dormice living on the northern periphery of their ranges show a high degree of adaptability to local conditions, but factors limiting their distribution are not clear yet.

Throughout most of the distributional range, the fat dormouse, Glis glis, relies heavily upon European beech as a key species in its habitat. In Lithuania however, situated beyond the continuous range of the beech, pedunculate oak becomes the essential tree in habitats of G. glis. In Lithuania, the dormouse activity season lasts from mid-May to mid-October, young are born during the short period from late July to mid-August, and the mean litter size is 5.9 young. Population density is low (0.8–2.0 ind./ha after hibernation and 1.2–4.8 ind./ha in autumn), but relatively stable. The mean body weights of adults (98 g after hibernation and 128 g before hibernation) are among the lowest across the range. Lithuanian dormice differ from those living in beech-dominated habitats by their lower population density and lower body weight. Such differences may be due to acorns being less suitable food for G. glis in comparison to beech nuts. In terms of inter-annual abundance dynamics, the G. glis population is comparatively stable as years in which dormice fail to reproduce are infrequent in Lithuania.

While most mammal populations show equalized sex ratios in their offspring, some species reveal deviations as a reaction to environmental circumstances. The recent study focuses on mortality, dispersal and biased sex ratio in the offspring of the edible dormouse (Glis glis) and their influence on next year's subadult population. Between 2002 and 2008 a male biased sex ratio in the offspring but an almost equal sex ratio of next year's subadult population has been found. Our results reveal that this deviation from the 1:1 sex ratio compensates a higher mortality rate of young males. The data used for this study were obtained from a mark and recapture project of monitoring the population biology of the edible dormouse performed north-east of Frankfurt/Main, Germany.

Evidence from the only woodland study in the U.K. of the non-native edible dormouse shows (using nest boxes inspected monthly), that whilst some or much breeding occurs in most years, non-breeding years also occur. This is understood to relate to the number of tree species flowering in spring and the amount of flower production. Morris & Morris (2010) used a small sample to show that some adult animals do not appear in the nest box inspection records during the non-breeding years, but are present during the next breeding year. We have subsequently refined and increased the database, collating information on a sample of 222 glis (136 female, 86 male) known to be alive for between 5 and 13 years during a continuous study period of 18 years. The number of old animals (living to at least five years) recorded in nest boxes is significantly different between years of breeding and non-breeding with up to 90 % absent. There is no evidence that they move elsewhere in the isolated wood. Both males and females displayed this trait. The paper discusses alternative explanatory options interpreted from this. The applied science impact is that if 18 month hibernation is proven the time and cost implications for population control planning are severe. Future research is aimed at demonstrating the reality.

Common dormouse (Muscardinus avellanarius) density in Transylvanian Plain is investigated using live-traps. Estimated population size is 39 individuals. Results using non-spatial methods combined with ad hoc calculations of the effective trapping area overestimated common dormouse density, both when using the naïve density estimation (27 ind./ha) and also when the “edge-effect” was accounted for by the addition of a boundary strip (16 ind./ha). Compared with published results using the same methods, our results are yet significantly higher. Spatially explicit capture-recapture approach yields lower density, of 13 ind./ha (maximum likelihood estimate), but still one of the highest densities reported for the species. Interspecific competition for traps was negligible at our study site.

Integrated Population Modelling (IPMs) is a computational method for estimating population and demographic parameters that can improve precision relative to traditional methods. Here we compare the precision of IPM to traditional mark-recapture analysis to estimate population parameters in the common dormouse (Muscardinus avellanarius). This species is relatively rare across its European range and field estimation of demographic parameters can be challenging, as several parts of the life history are difficult to observe in the field. We develop an IPM model incorporating dormouse nest counts and offspring counts, which is data often recorded as a standard part of dormouse nest box monitoring. We found a significant improvement in precision in the estimation of demographic parameters using IPM compared to standard mark-recapture estimation. We discuss our results in the context of common dormouse conservation monitoring.

Wild boar, Sus scrofa have been extinct in the wild in Britain for about 300 years. However, escapees from farm enclosures have been noted for over 20 years in parts of Southeast England, and populations of free-living feral boar have now established. Boar root for food on the woodland ground where hazel dormice, Muscardinus avellanarius hibernate in fragile nests and thus may impact on their population through predation. A group of twelve woodland sites assessed as suitable for supporting dormice and where wild populations of boar were known to have been present for ca. 20 years were chosen in Sussex (boar-positive sites). An additional twelve sites without boar presence (boar-negative) were chosen in the same region from the National Dormouse Monitoring Programme (NDMP). Fifty nest boxes were erected in early spring 2009 at each new site and all were inspected in June and October until the end of 2012. The numbers of individual dormice, empty nests found, and nest boxes used by dormice annually were compared between the two groups. The correlative GLM comparisons (using a negative binomial model) for all three indices were significantly higher in the boar-negative sites, suggesting that boar have negatively impacted on, but not eliminated, dormouse populations. Potential confounding variables including soils and woodland classification were investigated and were similar between the groups. Since the study was over a four year period any initial neophobic reaction to new nest boxes on the boar-positive sites would be unlikely to influence the result. We had no data for boar densities so could not evaluate boar versus dormouse density.

Roads are a threat to biological diversity. Especially the hazel dormouse (Muscardinus avellanarius) can be badly influenced by fragmentation due to its strictly arboreal activity. In this study a Northern German dormouse population living in roadside habitats and on road islands at crossroads was investigated to find out if road crossing is an exceptional behaviour or if it happens regularly. With capture-mark-recapture-method 30 crossings (mostly across a federal highway, three of them across a federal motorway) and via telemetry 27 crossings over federal highway and smaller streets were observed. Our study gives evidence, that road crossing can be a relatively frequent behaviour, as 18 % of the mark-recaptured and 60 % of the radio marked animals crossed roads, but it remains unclear, under which circumstances road crossing takes place.

The occurrence of hazel dormice on some islands in the Baltic Sea raises the question about the origin of these long isolated populations. The spread of hazel dormice from their Pleistocene shelters in southern Europe to the north was facilitated by a rapid spread of hazel during the Boreal after 10800 cal. yr BP and subsequently hazel dominated woodlands in central Europe. The immigration of the hazel dormouse from central Germany to Ruegen is not supported by findings and seems to be unlikely due to habitat fragmentation in the north-eastern German mainland. This is indicated by areas of poor sandy soils with poor pine forests besides wide and sandy river valleys and wetlands. In contrast, immigration via Denmark is rather possible considering the post-glacial development of the south-western Baltic Sea region. Especially the Darss Sill could have been used as a land bridge between south-eastern Denmark and north-eastern Germany about 9800 to 8800 cal. yr BP. A further migration of the species towards the east, e.g. to Bornholm, might be prohibited by the existence of the vast Oder River valley.

The suitability of two forest biotopes (oak and hornbeam-beech forests) for occupation by D. nitedula in Daghestan, Russia is considered. Biotopes have been characterized according to 11 parameters. All 11 vegetation parameters were significantly different between study areas. The indices of D. nitedula success in the studied biotopes demonstrated that numbers were higher in an oak forest than in a hornbeam-beech forest. Estimates of microhabitat distribution showed that D. nitedula individuals prefer to live in shrub associations and in areas with young trees in both biotopes. The body weight of adults and reproduction rate were similar in both biotopes. We concluded that in situation when the body weight and reproduction rates of individual D. nitedula were similar but the numbers of species in the both forest biotopes significantly differ, the structure of woody-shrub vegetation becomes a significant factor.

The genetic variation of the forest dormouse Dryomys nitedula (Pallas, 1779) from isolated populations of Russian Plain and the Caucasus was investigated using cytochrome b gene (cytb). The genetic distance calculated between these populations of forest dormouse was 9.94 %, which corresponds to the typical distance between biological species of mammals. The genetic distance of cytb between Western and Central Caucasus forest dormouse populations is also significant, 6.0 %. Probably, there was a long-term isolation of European and Caucasian areas of D. nitedula during the whole Pleistocene.