In the light of the threat to biodiversity and the need for effective and animal-friendly research methods, the aims of this study were to 1. investigate the relationship between scientific knowledge and the conservation status of dormice in Europe. A literature review was carried out to determine which species have been the subject of the most research and whether the Habitats Directive has had an impact. The hypothesis is that the dormouse species listed in the Habitats Directive have been the subject of extensive research, while those not listed have been neglected. 2. investigate the preference of dormice for nest-boxes or nest-tubes using a choice experiment. The hypothesis that dormice use nest-boxes and nest-tubes randomly according to their availability was tested. 3. develop and field test methods for the examination, marking and sampling of garden dormice, taking into account the welfare of the animals and the usability of the samples obtained. Publication 1: The research results on the four Central European dormouse species presented at the International Dormouse Conferences between 1990 and 2017 and published in the scientific literature since 1950 were analysed. The number of presentations increased over time for the hazel dormouse (N = 200) that is listed in the Habitats Directive and the edible dormouse (N = 150), while the number of presentations on the garden dormouse (N = 46) declined until 2014 and only appeared to increase again in 2017; there was no trend for the forest dormouse (N = 67) which is also listed in the Habitats Directive. The number of published scientific articles increased for all species except the garden dormouse. This focus reflects the wide distribution of the hazel dormouse and the edible dormouse, but does not fit well with the conservation status and current threats and conservation efforts for the garden dormouse. The results presented can be used to guide the reassessment of future research priorities and conservation strategies, as well as the implementation of new monitoring projects and ecological studies. Publication 2: In a two-year selection experiment, two methods for trapping and translocating hazel dormice were compared. This comparison can be used to guide the selection of methods in research or applied projects, and to clarify the role of competition for safe hiding places in the dormouse's habitat choice in this context. While the proportion of nest-boxes (n=156) and nest-tubes (n=156) occupied by dormice remained stable in both years (9.3% and 9.6%), the proportion of boxes and tubes occupied by Apodemus mice was lower in the second year (26.5% and 0.2%). In the first year, dormice clearly preferred nest-tubes over nest-boxes (p<0.05), in the second year the opposite was the case (p<0.001). The preference for one or the other device was mainly influenced by competition with Apodemus mice, which favoured nest boxes over nest tubes (p<0.001) when they were abundant in the first year. The hypothesis had to be rejected because dormice preferred nest-boxes over nest-tubes. In some years, however, competition with mice may lead to a higher use of nest-tubes by dormice. Publication 3: Facing the ongoing decline of the garden dormouse in large parts of Europe, methods for handling and sampling live animals of this species were described and data on the genetic diversity, weight, size and parasite load of live individuals (n = 156) from Hesse and Rhineland-Palatinate were collected. Blood was collected under Isoflurane-oxygen anaesthesia from the anterior vena cava or jugular vein. Sex, weight, tibiotarsal and tail length of all animals were measured. Genetic analyses (n = 64) using hair samples, examinations of mouth, eye and anal swabs (n = 156) for viruses and parasitological examinations of faecal samples (n = 57) were carried out. Genetic analysis of mitochondrial DNA revealed three haplotypes (WE4, WE4-3, WE5) in the study area. The microsatellite analysis showed a comparatively high genetic diversity with 66 % overlap of alleles, a low genetic distance (DJost 5.6 %) and a low differentiation index (FST = 0.02) between individuals from Hesse and Rhineland-Palatinate. All swab samples were negative for Borna disease virus. Cysts of protozoa and oocysts of coccidia, trematodes, cestodes and nematodes were detected in 47 % of the faecal samples. This enabled the successful establishment of methods and techniques for the examination, immobilisation and sampling of live dormice that are appropriate for animal welfare. Overall, this work has contributed to the scientific understanding of the biology of a previously neglected animal group. It has also provided effective methods for mapping and examining these animals in compliance with animal welfare standards.