The short version
- Hazel dormouse numbers at Killerton National Trust in Devon have remained stable since monitoring began in 2018, defying a national trend of steep declines.
- Experts attribute the local success to habitat restoration efforts, including the planting of hedges and trees that create connected corridors for the shy, nocturnal mammals.
- Bramble bushes play a critical role in the ecosystem by providing essential food sources and protective cover from predators during the active season.
Hazel dormice across the South West of England are preparing to enter hibernation as temperatures drop below the threshold that triggers their dormant state. While these small mammals typically weigh between twenty and forty grams, conservationists emphasize that they must have accumulated sufficient fat reserves to survive the winter months ahead. The timing of this seasonal shift is critical, as wet springs can disrupt foraging opportunities when the animals briefly awaken from hibernation.
At the Killerton estate in Devon, managed by the National Trust, recent data suggests a positive divergence from broader ecological trends. Rangers have installed one hundred nest boxes across the property and have been weighing and recording details of individual mice between April and October since 2018. This consistent monitoring has revealed that the local population remains fairly stable, a finding that contrasts sharply with national statistics indicating a decline of more than two-thirds in UK hazel dormouse numbers since the year 2000.
Conservationists point to habitat fragmentation as the primary driver behind the widespread reduction in dormouse populations. In contrast, the Killerton estate has focused on creating a healthy, diverse, and well-connected environment for wildlife. Fi Hailstone, a senior ranger at the site, noted that the stability of the local population indicates effective management practices. The trust has observed the animals spreading into new areas of the estate, which they attribute to increased planting of hedges and trees that facilitate movement and provide shelter.
The specific vegetation choices made by land managers appear to be a key factor in this localized success. Bramble bushes, often viewed negatively by gardeners due to their invasive nature, serve as a vital resource for dormice. These plants offer flowers in the spring and berries later in the season, providing essential nutrition. Additionally, the dense growth of bramble offers protective cover against predators, making it an ideal nesting site. This highlights the importance of maintaining scrubland alongside traditional woodland areas to support biodiversity.
Devon is considered a stronghold for hazel dormice largely due to its extensive network of hedges. These linear habitats connect larger patches of woodland, allowing the shy and nocturnal animals to travel safely across the landscape. The National Trust’s approach underscores the value of managing existing woodlands positively rather than relying solely on new planting initiatives. While new woodland creation is beneficial for long-term ecological health, its impact on dormouse populations may not be visible for another century.
The immediate focus remains on sustaining the current habitat quality to ensure the animals can continue to thrive. The monitoring scheme provides valuable data that helps rangers understand how weather patterns and seasonal changes affect the species. Warmer weather can prematurely wake hibernating mice, while adverse conditions during spring can hinder their ability to find food. By maintaining a resilient ecosystem with ample shelter and food sources, managers aim to buffer the population against these environmental fluctuations.
Public engagement also plays a role in conservation efforts. Individuals who encounter dormice during the winter months are advised not to handle them, as disturbance can be harmful. Instead, they should contact organizations such as the RSPCA or local animal shelters for guidance. This cautious approach helps protect the animals during their most vulnerable period. The success at Killerton offers a model for other landowners and conservation groups seeking to reverse declining trends in wildlife populations through targeted habitat management.
As the region moves deeper into winter, the stability of the Killerton population serves as an encouraging sign for conservationists. It demonstrates that localized interventions can yield positive results even when national trends are unfavorable. The continued monitoring will provide further insights into how these small mammals respond to ongoing environmental changes and management strategies. For now, the focus remains on ensuring that the habitat continues to support the species through the coming seasons.
Sources behind this briefing
Go to the original reporting
- BBC Science & Environment↗Dormice 'thrive' at National Trust site
