These ferret footprints are from a tracking tunnel used for monitoring small mammalian pests in New Zealand. A piece of meat is left in the tunnel and the ferret has to walk across an ink pad and over paper to get to the meat. Tracking tunnels are the best way to determine the presence of ferrets. Ferret footprints can be mistaken for stoat footprints, but they will often be larger than stoat footprints.
Image: Crown Copyright: Department of Conservation Te Papa Atawhai, 2014. From Gillies, C., Williams, D. 'A short guide for identifying footprints on tracking tunnel papers'. Department of Conservation, unpubl