The GWCT Mink Raft

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 km of river gives you multiple opportunities to detect each mink.  We have also shown that a single raft left for 2 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’s 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’s the extent to which the system is clear of mink that matters.

Please click for downloads on the GWCT Mink Raft 

References:

• Reynolds, J.C., Short, M.J. & Leigh, R.J. (2004)  Development of population control strategies for mink Mustela vison, using floating rafts as monitors and trap sites.  Biological Conservation 120(4): 533-543.
• Reynolds, J.C., Porteus T.A., Richardson, S.M., Leigh, R.J. & Short, M.J. (2010) Detectability of American Mink using Rafts to Solicit Field Signs, in a Population Control Context.  Journal of Wildlife Management, 74(7), in press.