Isolating the paws from the blobs

Over the autumn of 2018 volunteers, with Durham Wildlife Trust’s Heart of Durham and the Land of Oak and Iron Projects, have been conducting surveys around County Durham woodlands in their search for dormice.

Volunteers have been setting up footprint tracking tubes. These tubes constructed from drainage pipes were baited with hazelnut butter and a strip of paper which incorporated a small area of ink.

Tracking tube in situ

The idea being that the small mammals seeking out the bait would leave their footprints which could then be analysed, and hopefully if a dormouse passed through it would leave its prints.

Tracking paper taken from a tube showing the foot prints and inked section.

Small British mammals are shy, or nocturnal, or extremely elusive, but they often leave signs which indicate their presence. Signs such as footprints are very useful for recording different species of mammals, but it is rare to find a perfect print! A fact that the small group of volunteer surveyors found out.

A gathering on Wednesday 20th at Chopwell Forestry School of all those involved aimed to make some kind of sense of all the resulting strips of ink blobbed paper collected from the Autumn tube collections. Vivien Kent, Wildlife Conservation biologist guided the group through a process for recognising the shapes and patterns that small mammal footprints create. Rodents have four digits on the fore limb and five on the back and with distinctive shapes of the metacarpal pads, (below the digits), and heel pad varying between species. Woodmice, shrews and dormice, therefore will have not only have a print size variation, but the toe pad pattern will be quite different.

Dormice have a very distinctive triangular shaped metacarpals and heel pad as seen below.

The footprint cards were laid out and suddenly out of the blobs came recognition of shapes, and distinctive footprints.

Getting a perfect print of all digits is rare as rodents move at high speed hopping and skitting. Their frenetic activity leave a mass of footprints as the above image shows.

A card from Strothers Hill Wood, tube 57, produced the most exciting prints which only came to light with a hand lens. These series of tiny prints mingled with the larger prints but were so distinctive in shape once viewed through the lens.

Tube 57, larger print expanded
The small prints, found between the larger prints, which were only seen through a hand lense. Possibly prints of a shrew.

It was very exciting being able to identify different species so the group of volunteers are now fired up and are going to spend the year collecting prints. Working with Low Barns Photography group member Stan Potts the volunteers are hoping that by digitise some good quality images of prints these will act as reference guides to create a data base of foot prints which can be used as reference tools in their ongoing search for dormice.