Conservation of the
hazel dormouse
People’s Trust for Endangered Species, 3 Cloisters House, 8 Battersea Park Road, London SW84BG
Registered charity no 274206
Dormouse Conservation
• Finding Dormice – Survey methods
• Dormouse requirements and densities
• Problems for the species
• Mitigation suggestions
• Dormouse re-introductions
Dormouse survey methods
• Nut hunts
• Nest tubes
• Nest boxes
• Natural nests
• Hair tubes
Nut hunt methodology
• Requires presence of hazel
• Hole in nut – check tooth marks
• Search 5 x 10m2 for 20 min each
– no dormouse opened nuts found; unlikely to be present
• Collect 100 hazel nuts opened by voles,
mice and dormice (not squirrels)
– none opened by dormice; unlikely to be present
Nest tubes
• Cheap survey method
• Best used in hedgerows
• Used to demonstrate presence/absence
of dormice
– 50 tubes between June and Nov
– no dormouse evidence; species ‘unlikely’ to be
present
Methodology in Dormouse Conservation Handbook
Nest tubes
Nest Boxes
• Expensive survey
method
• Best used on vertical
stems
• Use for long-term
monitoring (NDMP)
– 50 boxes
– Grid approx. 20m apart.
Other survey methods
• Natural nests
– May require extensive
survey effort
• Hair tubes
– Cheap
– Use in large numbers
– Low success rate
Dormouse surveys - Good practice
• Does site fall in
known range
• Check for existing
records (LRC, NBN)
• Are dormice known to
be present?
• Conduct survey
• Report presence of
dormice to LRC
Dormouse surveys - Legislation
• Nut hunts, hair tubes, natural nests (no
disturbance)
– Non invasive, no licence required
• Presence of dormice unknown
– Nest tubes, nest boxes can be checked without
licence
• Presence of dormice known
– Nest tubes, nest boxes require disturbance licence to
check
Where to look for dormouse
–
–
–
–
–
–
–
Woodland but hazel is not crucial
Conifer wood
Scrub
Hedgerow
Small habitat areas
Roadside/railside verges
Dormice are probably under-recorded
Dormice may be present in any wood or
scrub habitat within their range
Important elements for dormouse
conservation
Habitat management to provide:
– plants for successional food
– plants for autumn food
– continuity of arboreal linkage
Dormice occupy small ranges so above are
needed within a relatively small area
Dormouse population density
Species
Habitat
Mean Spring
density
Dormouse
Optimal – diverse wood with
abundant, vigorous understory
4 to 6 adults
Dormouse
Oak woodland with hazel
2 adults
Dormouse
Scrub
unknown
Dormouse
Conifer woodland
1 to 3 adults
Dormouse
Hedgerow
1.3 adults
Wood mouse
Deciduous woodland
40 plus
Bank vole
Deciduous woodland
100 plus
Problems for dormice
• Inappropriate or lack of woodland
management
• Deer and rabbits
• Poor hedgerow management
• Habitat fragmentation
• Development
• Climate change
– Warm winters
– Wet summers
Mitigation for dormice
• Maintain and link areas of appropriate
habitat
• Increase plant diversity
• Initiate long term habitat management
• Dormouse nest boxes can increase habitat
carrying capacity
What’s good for dormice is good for lots
of other species
Dormouse reintroductions
Why reintroductions?
• Substitute for natural
recolonisation
• Restore lost range
• Stimulate
conservation effort
• Focus for landscape
restoration
Why are dormice
good?
• Key species
– Plant diversity
– Shrub structure
•
•
•
•
Woodlands
Hedgerows
Scrub
Responsibility
What’s good for dormice is good for
many other species
People’s Trust for Endangered Species, 3 Cloisters House, 8 Battersea Park Road, London SW8 4BG
Registered charity no 274206