The GWCT Mink Raft is a low-technology monitor, which encourages mink to leave evidence of their presence in the form of footprints. The raft uses a standardised mixture of clay and sand to record the tracks over a period of 1-2 weeks.
The tracking medium is problem-free and provides unequivocal evidence of mink presence. Once a mink is detected, the raft(s) on which it left its tracks also becomes the best place to set a trap. The commonest result is that the mink is caught next day.
Through a series of practical trials, we established that one raft per kilometre of river gives you multiple opportunities to detect each mink. We have also shown that a single raft left for two weeks within the range of a mink has a 50% chance of detecting that mink.
Given more than one raft available per mink and successive check periods, there is only a very small risk of failing to detect a mink that really is present. With this knowledge, rafts can also be used as a reliable indicator of mink absence. That's very important, because the number of mink caught is a poor guide to the success of the control effort. It is the extent to which the system is clear of mink that matters.
Downloads on using the GWCT Mink Raft
How to build the GWCT Mink Raft
How to cut Oasis blocks for minimal wastage