Dormouse-Friendly Forests
February 2020 Student of the Month – Ellie Scopes
PhD Research at University of Exeter
I am a 1st year PhD student at the University of Exeter, researching dormouse conservation and forest management in collaboration with Forest Research as a CASE partner. I am at the beginning of my research, still forming ideas about what to investigate, so this blog post will be about the context of my research and the general future aims. Updates on my progress will be posted to my wonderful Exeter research group’s website (https://wildlifescience.org/), my website (https://www.smallmammalgroup.com/) or on my twitter (@ScopesEllie, https://twitter.com/ScopesEllie).
Dormice are heavily protected due to legislation from both the EU and UK. This legislation makes it illegal to harm, harass or disturb a dormouse or its resting place, and imposes restrictions on the development of areas containing this species. This means all research and monitoring is carried out under licence, as it is seen as disturbance. Despite this protection, dormice are declining in the UK: by 72% between 1993 and 2014 (Goodwin et al 2017), and 51% since 2000 (Wembridge et al 2019). As such, the Mammal Society listed the hazel dormouse as Vulnerable in its 2018 Population Review. The greatest threats identified for UK dormice are climate change and habitat reduction:
Climate Change
Dormice require different weather conditions when they hibernate and when they breed. During hibernation, even though it seems a little counter intuitive, colder temperatures are better (Goodwin et al 2018) as the dormice use less energy. In warmer conditions, metabolic rates are increased, which uses energy and fat stores. They also prefer areas with stable temperatures, as fluctuations in temperatures also increases energy loss. Meanwhile, in the summer and autumn when they are breeding, dormice prefer sunny dry weather. This produces the greatest amount of food from plants and insects, which increases breeding success. Dormouse fur is not especially waterproof, so they cannot forage in wet weather, hence dry summers are best.
Under climate change, the UK is becoming milder and wetter in winter, which is likely to reduce the number of dormice that successfully hibernate. Warmer weather in summer may help compensate for this by increasing breeding success, but it is unclear how dormice are going to cope with climate change.
Habitat loss
Dormice eat flowers, fruits, nuts and insects, as they cannot digest leaves and bark. Therefore, they need a high diversity of plant species so that, throughout the year, they can always access some form of food in their small home ranges. This also means they prefer broadleaved woodland to conifers. They are also very arboreal and barely ever cross open ground, so they need woodland with lots of understorey connections to move around. High diversity, highly-connected woodland tends to be young, before larger trees form a closed canopy and shade out understorey plants, or woodland edges. This sort of habitat has been declining in the UK due to loss of woodland in general, but also a reduction in management such as coppicing that maintains younger stage woodland. There has been an increase in woodland management for conservation in recent years, but the best management regime for dormice is unclear.
My research
In my PhD I hope to understand how we can better manage woodlands for dormice, and so increase habitat suitability and boost their numbers; whilst also allowing forests to be used for other purposes, such as recreation and timber production. I would like to investigate the best regime for management, such as timings and extent, which has the most benefits for dormice populations, but also has minimal impacts of individuals in the area.
Dormice are incredibly well monitored in the UK through the National Dormouse Monitoring Programme by the People’s Trust for Endangered Species. This scheme relies on volunteers who train and obtain a dormouse licence to check nest boxes in the summer, and provides an amazing data set for research. Local efforts are often coordinated by county mammal groups, and I would encourage anyone interested to get involved, and thank all of the existing volunteers for their hard work.
References
Goodwin, C., Hodgson, D., Al‐Fulaij, N., Bailey, S., Langton, S., Mcdonald, R. (2017). Voluntary recording scheme reveals ongoing decline in the United Kingdom hazel dormouse Muscardinus avellanarius population Mammal Review 47(3), 183-197. https://dx.doi.org/10.1111/mam.12091
Goodwin, C., Suggitt, A., Bennie, J., Silk, M., Duffy, J., Al‐Fulaij, N., Bailey, S., Hodgson, D., McDonald, R. (2018). Climate, landscape, habitat, and woodland management associations with hazel dormouse Muscardinus avellanarius population status Mammal Review 48(3), 209-223. https://dx.doi.org/10.1111/mam.12125
Wembridge, D., White, I., AL-Fulaij, N., Marnham, E., Langton, S. (2019). The State of Britain's Dormice 2019 https://ptes.org/wp-content/uploads/2019/11/SoBD-2019.pdf
