The National Dormouse Footprint Tunnel Survey: informing conservation action for an iconic species

The National Dormouse Footprint Tunnel Survey: informing conservation action for an iconic species - People’s Trust for Endangered Species

Gaining key insights into how to manage hedgerows for dormice

Recently launched, the National Dormouse Footprint Tunnel Survey will use footprint tunnels to detect the presence or absence of the charismatic but rare hazel dormouse in hedgerows. The need for surveying hazel dormice is clear: it is thought that their population has halved in the last 22 years alone. By combining footprint tunnel surveys with the Great British Hedgerow Survey, we might also gain some key insights into how to optimally manage hedgerow habitats for this iconic species.

How to gather information from footprint tunnels

The tunnels themselves consist of black square downpipe. Inside, a strip of white card attached to a plywood tracking plate is placed, with a homemade charcoal / olive oil ‘ink’ applied at either end. The inquisitive nature of dormice encourages them to explore the tunnels. Their presence is recorded through the presence of footprints with one tell-tale feature in particular; the hazel dormouse has distinctive triangular-shaped pads on both the hind and front feet.

Unlike previous surveys, the National Dormouse Footprint Tunnel Survey provides a systematic means of surveying the presence of dormice across Great Britain. Probability scores, showing the likelihood of detecting dormice if they are present, have been calculated. These scores depend on survey effort there is, for example, a 95.6% chance of detecting a dormouse if present when 20 footprint tunnels are placed along a hedgerow for a period of 10 weeks. Footprint tunnel surveys have the added benefit of not requiring a dormouse license.

Although Bright and McPherson (2002) found that the range of dormouse presence in hedgerows declined by 64% between 1970 and the turn of the 21st Century, we don’t actually have an extensive knowledge of which hedgerows dormice are using. We do know that a higher dormouse abundance is associated with taller hedges and that dormice are associated with species-rich, particularly ancient hedgerows. Being successional feeders and eating a varied diet throughout the year, this is unsurprising.