Hazel Dormouse Muscardinus Avellanarius Research Articles

Machine learning identification of microhabitat features associated with occupancy of artificial nestboxes by hazel dormice Muscardinus avellanarius in a UK woodland site

Hazel dormice Muscardinus avellanarius have severely declined since 2000 leading to increased legislative protection in the UK and Europe. Artificial nestboxes are widely used for its conservation and monitoring. Previous research has focused on how to identify suitable areas for nestboxes, but where to place individual boxes to promote occupancy is less well understood. Here, we demonstrate the use of machine learning Random Forest regression to predict nestbox occupancy from a wide range of microhabitat variables using a UK woodland as a case study. Random forest models are powerful predictive tools that allow simultaneous testing of many predictors with relatively few observations.Field data included observed nestbox occupancy (2017–2021) and measurements of 76 microhabitat variables collected in the summer of 2021 from 45 occupied and unused nestboxes located in a deciduous woodland in Berkshire, UK. We applied Random Forest regression to identify important variables and predict nestbox occupancy demonstrating robust approaches to tune model hyperparameters and evaluate importance metrics.In our study area, nestboxes were more likely to be occupied in sites with more hazel Corylus avellana, greater overall tree abundance but not fully closed canopies (optimal 80–85%), more honeysuckle Lolium periclymenum and hawthorn Crataegus monogyna, and when located further from footpaths and woodland margins. Occupancy over the study period was well predicted using microhabitat variables (13.3% OOB error) but future occupancy was more uncertain (33.3% error for 2021–2023 records).Modelling approaches that allow consideration of numerous variables from few locations or observations can be help identify relevant features and predict desirable outcomes of conservation actions. Here we demonstrate this approach identifying microhabitat variables that influence artificial nestbox occupancy by hazel dormice in a UK woodland. Findings offer some recommendations for local management that could promote nestbox occupancy and improve monitoring and conservation efforts.

Density and climate effects on age‐specific survival and population growth: consequences for hibernating mammals

AbstractThe impact of factors such as density dependence, food availability and weather are known to be important for predicting population change in a wide range of species. However, a challenge in ecology is understanding the contributory and interactive role of these drivers on populations. This is necessary to design effective conservation and management strategies. Using data from long‐term studies of five hazel dormouse Muscardinus avellanarius populations in Europe, we tested the relationship between population density and weather and their impact on demographic rates. We used an integrated population modelling approach, estimating age‐specific overwinter survival, annual population growth and fecundity rates. We found strong negative effects of population density, precipitation and winter temperature on population growth rates. This suggests that warmer and wetter weather negatively affects dormouse survival for both adults and juveniles, but we found subtle differences in these effects between age classes. We also identified an interaction between weather measures and population density on age‐specific survival, possibly as a result of weather impacts during hibernation. Although we found low winter temperature was positively associated with population growth, we found evidence consistent with density dependence. We discuss our results in the context of woodland habitat conservation management.

Harnessing practitioner knowledge to inform the conservation of a protected species, the hazel dormouse Muscardinus avellanarius

Abstract Conservation decisions are typically constrained by the availability of published evidence. Practitioners and non‐academic experts often possess additional knowledge, including about the practical plausibility of conservation actions, which may lead to more effective planning and outcomes. However, practitioner knowledge is rarely considered during formal evidence syntheses. Alongside a formal literature review, we conducted 26 interviews involving 38 conservation professionals to elicit their knowledge of the conservation of a protected and declining species in England, the hazel dormouse Muscardinus avellanarius. Practitioners and non‐academic experts provided additional insights about dormouse ecology and conservation, beyond those synthesized from the published literature, though we found few contradictions between these different information sources. Instead, practitioner knowledge helped to verify, clarify and expand upon evidence from empirical studies. In general, practitioners emphasized that dormice are far more adaptable than traditionally perceived, with thriving populations found in hedgerows, scrub, road verges and railway verges, rather than solely within broadleaf woodlands. Proposed opportunities for restoring dormouse populations included improving hedgerow management, creating new woodlands, bringing existing woodlands back into management, setting aside unproductive land and improving habitat connectivity. However, participants emphasized the need for landscape‐scale approaches, accounting for the impacts of climate change, and better surveying and monitoring. Key practical considerations included overcoming time and financial constraints, providing better advice, knowledge and training, changing attitudes of land owners and managers and balancing other demands such as agricultural productivity and the requirements of other species. Despite the insights they provided, participants highlighted many remaining knowledge gaps. These included uncertainties arising from the published literature, as well as scarcely studied topics that are of major practical importance, namely the effectiveness of dormouse mitigation measures in planning and development, and the impacts of anthropogenic disturbance and pollution on dormice. Our findings improve the evidence base for restoring hazel dormouse populations and for further empirical evidence gathering. More generally, the study highlights how practitioner knowledge can help both to supplement traditional published evidence and to better frame conservation programmes, which may lead to more successful outcomes.

The effect of climate on age specific survival and senescence in a Hazel Dormouse (Muscardinus avellanarius) population in Lithuania, across 1997-2021

It is well known that survival and the dynamics of wild populations are affected by environmental factors. Recent research has found that, among some species of mammal, differences in environmental conditions between populations of the same species translate into changes in infant and juvenile mortality, but not in the rate of senescence (‘rate of aging’). This has been confirmed among primates and some species of carnivores, but has not been tested on other taxonomic groups, such as rodents. Here, we analyse age-specific survival and mortality on the most extensive capture-mark-recapture data set on Hazel Dormouse available from Lithuania. We used Bayesian survival trajectory analysis (BaSTA) and tested different models of age-specific mortality. Since the Hazel Dormouse population is in decline across its northern distribution, potentially in response to climate change, we divided the data into three periods to assess changes in survival over time. Regional climate data were obtained from the NOAA data service to test the effect of climatic factors on survival during winter and summer respectively. Our results show that, during all three periods, male life expectancies were longer than those of females. We found that the overall level of mortality was high for all three periods, with lowest mortality during the period 1999 - 2004. We found large differences in juvenile mortality and age-independent mortality between the three periods, but not in adult mortality or in the rate of senescence. This is consistent with previous findings on other mammals, supporting the invariant rate of aging hypothesis.

Alpine forests are a suitable habitat for the Hazel Dormouse

The Hazel Dormouse (Muscardinus avellanarius) is commonly considered a typical lowland species, occasionally observed at higher elevations in mountain habitats. This study began with preliminary investigations in the Gran Paradiso National Park in the Western Alps, where nests of Hazel Dormice were observed at around 2000 m a.s.l. In 2019, a mark-recapture project started in two valleys (Valsavarenche and Val di Rhêmes), positioning six grids with 40 nest boxes from 1000 m to 2000 m a.s.l. to investigate the ecology and adaptations of dormouse populations along the altitudinal gradient. In these years, nest boxes were checked irregularly, and the number of marked animals was low. The number of individuals captured in the highest grids at 2000 m increased from 1 to 8 in Valsavarenche and from 11 to 15 in Val di Rhêmes. These results seem to confirm a continuous presence of the species at the upper edge of the forest vegetation. The data from Valsavarenche suggest some significant population fluctuations, but the effect of nest boxes on population densities cannot be excluded.

Distribution and habitat use by sympatric dormice species in two Natura 2000 sites in central Macedonia, Greece

There has been little research on the distribution and ecology of the four dormouse species occurring in Greece; the Edible Dormouse (Glis glis), Forest Dormouse (Dryomys nitedula), Hazel dormouse (Muscardinus avellanarius) and Mouse-tailed Dormouse (Myomimus roachi). As a result, the latter three species are listed as data deficient (DD) in the National Red Data Book. Recently, the government has tried to address this knowledge gap, funding dormouse surveys within the Natura 2000 network. In this context, we used a combination of nest-tubes (n=442) and track-tunnels (n=238) to study dormouse distribution and habitat use across 37 sites representing different habitat types (with varying levels of grazing) of two mountainous N2K sites (GR1270001, GR1270005) in central Macedonia. We detected G. glis at 28 sites, D. nitedula at 32 sites, and M. avellanarius at seven sites. Positive identification of the different species was twice as likely in track-tunnels (unbaited; metal sheets covered in soot) than nest-tubes. We estimated relative abundance across sites using Royle-Nichols occupancy models, except for M. avellanarius due to data limitations. For all species, we examined habitat use using MaxEnt ecological-niche models. Our findings show that D. nitedula has the widest distribution, occurring even in sparse forests and maqui with moderate or high livestock grazing intensity. G. glis is common, but restricted to medium-high elevation forests. M. avellanarius appears to have a discontinuous distribution. If this study is representative of its status across the country, that species requires conservation efforts.

Structural re-design of the Animex Wildlife Bridge for the Hazel Dormouse (Muscardinus avellanarius): Lessons Learnt from Two Connectivity Mitigation Case Studies in England

The Hazel Dormouse is an arboreal mammal present in Europe and Asia Minor. The population is declining in the United Kingdom (UK), partially due to habitat fragmentation caused by the development of roads and other linear infrastructure. In 2016, we designed and tested an arboreal bridge in Britain that proved to be effective for Hazel Dormice. Subsequently, the bridge materials were upgraded to meet the technical standards of UK road agencies, so that it could be approved and implemented as mitigation on projects throughout the country. In the UK, each bridge must be technically certified by the relevant road authority and, as the bridge is a unique structure, this can pose challenges on projects. Two installation designs were created: the ‘standalone’ bridge and the ‘retrofit’ bridge. Several bridges have now been installed above roads in the UK. We discuss the development and implementation process from two case studies: a 40-metre retrofit bridge to an underpass at St Athan in Wales and two 76+ metre bridges retrofitted to an overbridge and underpass on the M1 motorway at Gayhurst, Buckinghamshire. This poster discusses what we have learned from these projects, how they have influenced the future designs of the Animex wildlife bridge, and the production of best practice guidance to provide a summary of the entire process of implementing a bridge project.

The contribution of dormice monitoring to the assessment of the conservation status of species in Latvia in accordance with IUCN criteria

In Latvia, four dormouse species have been recorded. In 2016 an annual monitoring of the Hazel Dormouse (Muscardinus avellanarius) and Forest Dormouse (Dryomys nitedula) was commenced within the national biodiversity monitoring programme to obtain data that would allow assessmen of the conservation status of those species and their habitats. The nestbox method was used for the surveys, as it is equally suitable for collecting data on all four species of dormice. Since 2016, 133 temporary study plots with 5–15 nest-boxes each, were established all over the country to record species presence. Sevenadditional permanent study plots collected data on population dynamics, each consisting of at least 50 nestboxes placed within a grid system at 50 m intervals. No Garden Dormice (Eliomys quercinus) were recorded, supporting the presumption that this species has vanished in Latvia. A new location for Edible Dormouse (Glis glis) has been discovered. The Forest Dormouse is found exclusively in a small area near the Latvia-Belarus border, but Hazel Dormice found in Latvia are probably are part of a metapopulation located to the south. No overlapping of distribution areas of species was found. The previous assessment of dormouse species, according to outdated IUCN criteria, was done 20 years ago. Re-assessment according to current IUCN criteria, and using monitoring data, is now carried out within the recently commenced LIFE FOR SPECIES project (2021–2024). Preliminary assessments indicate that each dormouse species will be classified in different categories - rangingfrom Least Concern to Regionally Extinct.

Status and distribution of dormice (Mammalia, Gliridae) in Bulgaria

Here we summarize all available data about dormice (Gliridae) in Bulgaria, published one and our own observations, collected in the last 20 years. Four species are found in Bulgaria - the Forest Dormouse (Dryomys nitedula), the Edible Dormouse (Glis glis), the Hazel Dormouse (Muscardinus avellanarius) and the Roach’s Mouse-tailed Dormouse (Myomimus roachi). Altogether we collected 1200 records from 283 locations. A database has been created in which every single record is kept. The most common and widespread species are the Edible (G. glis) and Forest Dormouse (D. nitedula), found in 212 and 139 locations respectively. They inhabit mainly the deciduous and mixed forest in the country. The Hazel Dormouse (M. avellanarius) is found in 77 locations, the bulk of them are in the mountains, but there are some locations along the Danube and southeast Bulgaria. It prefers woods with a well-developed understorey. The Roach’s mouse-tailed dormouse (M. roachi) is the rarest one - found in 26 locations in southeast Bulgaria. In contrast to the other dormice, it avoids woods and lives in semi-open habitats with shrubs, tree lines, and islands in grasslands and agricultural fields. There are several anecdotal reports of the Garden Dormouse (Eliomys quercinus) but no hard proof exists for the presence of this species. We discussed the patterns of distribution, conservation status, and coexistence of Bulgarian dormice.

Distribution of Glirids in an Alpine national park

In this long-term study, we evaluated the distribution of three species of Glirids: Hazel Dormouse (Muscardinus avellanarius), Garden Dormouse (Eliomys quercinus) and Edible Dormouse (Glis glis) in the Gran Paradiso National Park (Western Italian Alps). The aim was to investigate the ecology, adaptation strategies, and distribution of these dormouse populations along an altitudinal gradient. Monitoring started in 2015 and is still ongoing. We used five different techniques (searching for nests, grids of nest boxes, transects of live traps, nesting tubes, and footprint tunnels), placed along an altitudinal gradient from 700 to 2300 m a.s.l. We found a total of 680 signs of the presence of Hazel Dormouse and 46 individuals, 275 signs and 142 individuals of the Garden Dormouse and 674 signs and 67 individuals of the Edible Dormouse. The three species selected different altitudinal gradients: Edible Dormouse from 800 to 1700 m, with a prevalence between 800-1100 m; Garden Dormouse from 1100 to 2000 m, with a prevalence between 1400-1700 m. The Hazel Dormouse was ubiquitous from 800 to 2032 m, without a clear altitudinal pattern. Edible Dormice were mainly found in deciduous and mixed forests, while Garden Dormice usually occurred in coniferous forests. The Hazel Dormouse seemed to be regularly distributed in all forest types up to the tree limit. These results, obtained from diverse methodologies, permitted comparison between the monitoring protocols, improved knowledge of habitat selection by Glirids in Alpine habitats, as well as providing novel insights within the context of climate change.

Settling in: space utilization behaviour of translocated Hazel Dormice (Muscardinus avellanarius)

The Hazel Dormouse (Muscardinus avellanarius) is protected under the EU’s Habitat Directive and its national implementation, whereby physical harm to individuals as well as the destruction of breeding and nesting sites is prohibited. Within the context of inevitable environmental impacts these protection goals are not always maintained. Therefore, mitigation and compensation measures to secure a population’s viability are required. For sedentary and less mobile species like the Hazel Dormouse, mitigation often includes the translocation of individuals to a different habitat patch. In 2017 and 2018 a total of 108 individuals were translocated from an old growth oak-hornbeam forest to an area that was re-forested 40 years ago. Prior to translocation, individuals were equipped with a radio transmitter and they were followed for three consecutive nights and one control night, during which bearings were taken every five minutes using the triangulation technique. A control group of established Hazel Dormice was followed in the same manner. Nests and resting sites were searched for during the daytime. Twelve male Hazel Dormice were radio-collared and between 234 and 427 bearings were taken per individual. Resting sites of translocated dormice were mainly located within the forest canopy (33.3%). Furthermore, individuals were often found active during the daytime. Mean activity range size (MCP) and resource search areas (LoCoH 95 %) were larger in translocated dormice, whereas the mean core habitat size (LoCoH 50 %) was larger in established dormice. The activity range during all of the monitored nights overlapped significantly more in established dormice, demonstrating exploratory behaviour by translocated individuals.

Distribution data of the dormice species in Romania: a review

All four species of dormice present in Romania are listed as Vulnerable in the Romanian Red Book of Vertebrates and are protected by national laws. Even though they are important bioindicators of the condition of forest habitats, little is known about their distribution. We reviewed the distribution data for the Romanian dormice species: the Garden Dormouse (Eliomys quercinus), Hazel Dormouse (Muscardinus avellanarius), Edible Dormouse (Glis glis), and Forest Dormouse (Dryomys nitedula). Our sources include published scientific literature, online databases (such as GBIF, Observation.org and iNaturalist), museum collections, verified citizen’s data as well as original data. A database was organized in GeoPackage format in QGIS 3.16.0. Historical locations from old scientific papers were georeferenced and included in the database with all metadata found. Recent and original data locations were recorded using geographical coordinates. Our aim was to produce up to date distribution maps for the dormice species occuring in Romania that can be further used in potential habitat modelling for the study and protection of these species and their habitat. We found the most abundant observation were of Muscardinus avellanarius and the least recorded species was Eliomys quercinus, without any recent data.

Developing an environmental DNA protocol for Hazel Dormouse surveys

Recording Hazel Dormouse (Muscardinus avellanarius) presence allows conservation and mitigation efforts to be effectively directed towards populated sites. As it is a protected species, licences are required for survey methods which disturb the animals or their habitat. Therefore, reliable low disturbance survey techniques are desirable. In this study, we tested the potential of detecting environmental DNA (eDNA) from soil as a survey method for dormice. Firstly, we designed species-specific primers and the associated PCR protocol using tissue samples from Hazel Dormice. To ensure specificity, we also checked the protocol against tissue samples from non-target species. Next, we collected soil samples from occupied sites in England to test the methodology with environmental samples. This included testing site-level heterogeneity of dormouse DNA distribution and localised level DNA distribution surrounding occupied nest boxes. Finally, we tested the soil for DNA presence changes over time, after removal from the site. Using eDNA for dormouse surveys is promising. Our results indicate that a usable survey methodology can be developed, providing a relatively low cost and time-efficient tool when compared to existing dormouse survey methods. Future work should aim to further understand the changes of dormouse eDNA through time. Through identifying populated sites, eDNA could support mitigation projects and help to direct dormouse conservation efforts.

Hazel Dormice (Muscardinus avellanarius) on the move in Nottinghamshire, England: A reintroduction success

Historical records from 1885 suggest that the Hazel Dormouse (Muscardinus avellanarius) was once present in Nottinghamshire. However, the species was thought to have become locally extinct as recently as the 1950s. After a failed attempt in 1994 to reintroduce Hazel Dormice back to the county, the species was finally returned to three neighbouring woodlands in north Nottinghamshire as part of a three-year project in 2013/14/15, Treswell Wood, Eaton Wood, and Gamston Wood, respectively. Data collected as part of the National Dormouse Monitoring Programme (NDMP) indicate a stable population in all three of the Nottinghamshire reintroduction woodlands, whereas dormouse declines have been reported in many southern populations. The Nottinghamshire Dormouse Group employ a range of survey techniques to monitor the populations and surveys in neighbouring habitats have confirmed that the dormice are steadily dispersing into the wider landscape. Dormouse presence has now been confirmed in two additional woodlands, including one approximately 600m from the closest reintroduction site. Dormice have also been recorded inhabiting nestboxes within trackside vegetation along the East Coast Railway line, including a dormouse nest on the far side of the high-speed (100mph) railway line, confirming that at least one dormouse has crossed over the track. A 5-year, landscape-scale PIT-tagging project commenced in September 2021 with the primary aim of investigating the dispersal capabilities and seasonal movements of the dormice. The project scope will include the three reintroductions woodlands, all woodlands in between and the connecting hedgerows. The data will be used to inform future dormouse reintroductions.

Genotyping-by-sequencing based SNP discovery in a non-model rodent, the endangered hazel dormouse

The hazel dormouse Muscardinus avellanarius presents an exemplary non-model species that is both locally threatened and whose genetic status is not fully understood owing to insufficient resolution of the currently available molecular tools. We performed normalized Genotyping-by-Sequencing (nGBS) on 48 hazel dormouse samples collected across the species European distribution, aiming at discovering useful single nucleotide polymorphism (SNP) markers for the assessment of population structure and genomic diversity. The analyses of > 24,000 SNPs showed a high divergence between the Eastern and Western lineage of the species with high rates of SNP allele fixation, consistent with previous studies suggesting the divergence of lineages occurred over 2 mya. These results indicate that investigating inter-lineage as well as within-lineage genetic composition will be a conclusive approach for identifying conservation strategies in the future. Results presented here indicate the highest genetic divergence in the Italian and Lithuanian populations. We document how nGBS allows the discovery of SNPs that can characterize patterns of genetic variation at multiple spatial scales in a non-model organism. We document how nGBS allows the discovery of SNPs that can characterize patterns of genetic variation at multiple spatial scales in a non-model organism, potentially informing monitoring and conservation strategies.

The elusive winter engineers: structure and materials of hazel dormouse hibernation nests

AbstractTrade‐offs between specialist use of particular resources and opportunistic use of widespread materials may present different strategies for survival. Hazel dormice Muscardinus avellanarius are arboreal mammals that in Great Britain hibernate from late autumn to mid spring in nests that are specially built at ground level. Hibernation nests are rarely encountered, and little is known about the types of construction or materials used. Specifically, it is not known whether nest materials are selected opportunistically, based on their availability, or are specialised to suit local environmental conditions. We therefore conducted a study to characterise the main materials used to construct these nests, explore the distances travelled to collect materials and investigate whether regional climate and/or local microclimate have an impact on the types of nests built. Thirty‐three hibernation nests were located through radio‐tracking, systematic searches and incidental finds. Structurally, hibernation nests were built similarly to summer nests and were most commonly constructed with an outer layer of leaves and distinct core section made of woven material. We found no correlation between nest type and the temperature recorded at nest sites. Nests were built using a mean of two materials per nest, which were both in every case available within 3m of the nest. The most frequently used materials were bracken, hazel and beech leaves, and grasses. Dormice were flexible in their use of nest materials, using various materials harvested very locally. However, dormice travelled further to collect grasses, ferns, bracken and honeysuckle, and these materials made up most of the nests in which they were found. There were also positive correlations between material abundance and usage, and suitable materials for hibernation nest construction were therefore readily available within their home range.

Flexibility in thermal physiology and behaviour allows body mass maintenance in hibernating hazel dormice

AbstractStudying animals under natural or semi‐natural conditions is essential to better understand the implications of a warming climate on species survival. Here, we provide evidence of the effects of increasing winter ambient temperature (Ta) on the thermal physiology, feeding behaviour and body mass (BM) of a small mammalian hibernator, the hazel dormouse Muscardinus avellanarius. We collected skin temperature, metabolic rate (MR) and BM data from captive, hibernating dormice exposed to two winters of differing intensity in outdoor aviaries. Additionally, we obtained skin temperature data from one free‐ranging individual during the hibernation period. Statistical modelling showed that Ta and time since the start of hibernation both had significant non‐linear effects on the probability of arousal from torpor. During the warmer winter (Ta<0°C on 26 days), foraging resulted in higher BMs for some individuals, despite more frequent arousals, than during the colder winter (Ta<0°C on 86 days). As expected, Ta had a non‐linear effect on MR during torpor, with the lowest energy expenditure at intermediate Ta, and normothermic MR was minimal when Ta was warmer. The negative effect of increased arousal frequency on BM was counteracted by the positive effect of foraging on BM. Conforming with the accumulating body of evidence on high flexibility in physiological responses in many small mammals, we found that the thermoregulatory and behavioural responses of dormice during hibernation were more flexible than previously observed for this temperate, fat‐storing species. The ability to respond to prevailing environmental conditions might help M. avellanarius cope with increasing winter Ta predicted for ongoing global warming.

Fragmentation of Habitats in Two Dormouse Species (Gliridae, Rodentia) and Protection of Biodiversity of Broad-leaved Forests in Nizhny Novgorod Oblast

Little is known about the distribution of dormouse species in the Middle Volga region. The habitats of the Edible Dormouse Glis glis L. and the Hazel Dormouse Muscardinus avellanarius L. are fragmented and mainly lost in the agricultural landscape of the right bank of the Volga River and in the coniferous forests of the right bank of the Lower Oka River in Nizhny Novgorod oblast. New data are given of features of the habitats of two sympatric dormouse species from a patch of a lime–oak forest surrounded by coniferous forests. Within the area studied, 80 wooden nestboxes were put up in places with well-connected tree canopies and well-developed understory. Over the three years of our study (2016–2018), preliminary data were obtained on the dynamics of nestbox use and the relative abundance and reproduction of both dormouse species. The patch of the lime–oak forest with an area of approximately 20 ha is divided into two parts by a road and a 50 m-wide glade. Both parts did not differ in vegetation, but the Edible Dormouse was found only in the southern part. The Hazel Dormouse was found throughout the whole lime–oak patch, except for woodplot no. 1 (1.5 ha), which was occupied by the Edible Dormice with a high density. On the basis of the data obtained, management actions are suggested to raise the level of connectivity and immigration in the population of isolated broad-leaved patches in coniferous forests, in particular, to develop a network of “key habitats.”

Assessing the occupation of nest boxes by dormice (Gliridae) in the Carpathian forests

Abstract Nest boxes for dormice (Gliridae) can significantly increase the habitat’s carrying capacity for these species in areas under high anthropopressure and facilitate the long-term monitoring of populations. As part of the active protection of dormice in the Carpathian Landscape Parks in Małopolska, in August and September 2019, 575 boxes of two different sizes were checked for the presence of adults, young or nests. Additionally, habitat conditions within a 25 m radius were recorded (e.g. forest stand, estimated understory cover, the approximate number of natural shelters, fruiting plant species). The vast majority of all nest boxes – 79% – were used by dormice, but also birds and insects frequently occupied these shelters. Out of four species of dormice that occur in Poland, two were recorded in the study area: hazel dormice Muscardinus avellanarius and fat dormice Gli sglis. They were found in all surveyed landscape parks and inhabited mainly fir stands. Hazel dormice preferred smaller nest boxes and were generally more common than fat dormice, which preferred large boxes. On the other hand, fat dormice were more common in areas rich in fruiting plant species. Our research thus confirmed the usefulness of artificial shelters for dormouse in active protection.

Footprint tunnels are effective for detecting dormouse species

AbstractGlirids are arboreal rodents that are difficult to monitor due to their nocturnal activity and their relatively low density. We compared results from footprint tunnels with those from two other monitoring methods (nest boxes and nesting tubes) for three dormouse species in an occupancy framework. Footprint tunnels performed better than the other two methods for the hazel dormouse Muscardinus avellanarius and the edible dormouse Glis glis, and were the only method which detected the garden dormouse Eliomys quercinus. Our findings provide evidence to support the effectiveness of footprint tunnels in monitoring the occurrence of dormouse species in comparison with other methods.