Neale 2008 Spatial orientation and foraging behaviour of wild caught and captive bred dormice during reintroductions
Title: Spatial orientation and foraging behaviour of wild and captive-bred dormice during
reintroductions, Royal Holloway Individual Research Project, 2008
Author: CJ Neale
Background to study
Hazel dormice have undergone a rapid decline in the UK and conservation efforts aim to restore
populations within their historical range and to secure extant populations to prevent any further
losses. Due to the poor dispersal ability of dormice, reintroductions of both captive bred and wild
caught individuals are seen as a valuable tool. It is important to understand the factors that may
affect the success of introductions, such as whether the individual is captive bred or wild caught.
- 21 wild-caught and 19 captive-bred dormice were released into a 30 ha deciduous woodland
dominated by oak with a species rich understorey.
- All individuals were released using a soft release method involving an 8 day acclimatisation
phase in pre-release pens located within the new site. Individuals were provided with the same
food and water ad lib and were released in the same groups they had been living in pretranslocation.
- Dormice were fitted with radio collars after 6 days of being in pre-release pens and were tracked
for 8 nights following their release. Fixes for each individual were obtained every 40 minutes per
night and the number of about turns, mean speed, time stood still, and travel distances were
used to assess differences in the movement behaviour of individuals (male, female, captive and
wild caught) where >15 fixes were obtained.
- Male dormice had larger home ranges (0.62 ha) than females (0.15 ha) and tended to travel
further, faster and spent less time standing still.
- Both male and female dormouse activity was concentrated around two distinct clusters
suggesting the exploitation of seasonally available food sources.
- There was no difference observed in the ranging behaviour or wild caught or captive bred
Key messages to landowners and managers derived from these results
- Reintroductions should be conducted using a ‘soft release’ method where individuals are kept in
release pens to acclimatise for approximately 8 days during which they are given supplementary
food of similar composition to their diet at origin.
- Dormice release sites should have a high diversity and density of trees and shrubs which provide
seasonal food sources and as such can be exploited by reintroduced individuals. Reintroductions
should be conducted when and where preferred food resources are available.
- Both captive bred and wild captured individuals are suitable for reintroductions.
Hazel dormouse; Muscardinus avellanarius; reintroductions; soft-release; home range; ranging
behaviour; radio tracking