Below are some of the most common questions we get asked, if your question is not covered please contact us.

American mink are an invasive non-native species which means they have been brought in from another country and have a detrimental impact on our native wildlife. They predate on ground nesting birds, fish and small mammals. Their impact has probably been greatest on the water vole, where the population has declined faster than for any other mammal in the UK. American mink adapt their feeding behaviour according to prey availability and once they have reduced one food source they simply move onto another.

Please see Impacts for further information.

Certainly, anyone can get involved simply reporting sightings or field sign of American mink is a great help. Information about their presence is mapped and our co-ordinators can let other volunteers know of any mink around in their area. If you have access to a suitable water body you could put in a raft and; check the tracking plate for footprints and; check traps daily once mink have been detected. Not everyone is willing or able to trap and dispatch mink, if that part is difficult we can usually find someone to help with this aspect. If you can do trap/dispatch that is great, even better if you can help others dispatch mink when needed.

The traps we provide are live capture cage traps and come with an otter guard; this reduces the entrance of the trap to around three inches effectively excluding adult and young otters. Alternatively two pieces of doweling can be placed into 12mm drilled holes at the end of the tunnel to restrict the size of the entrance. Some smaller non-target animals, such as water voles, can fit through the otter guards these are released unharmed when the cage traps are checked. It is illegal to release mink after capture.

Although not always possible to achieve, an ideal raft density would be one raft per km of river; research shows that this allows each mink access to at least one raft, but usually two or three. For open water, such as the broads or fishing lakes you can follow the same spacing along the water’s edge. For land with many ditches or channels, i.e. marshland, it is suggested to have one raft per square km as a starting point, more maybe necessary depending on the density of the ditches. When mink are scarce, rafts can be deployed at a lower density to look out for their return.

There is no set time for this. However, our experience is that most mink are caught within a week, if at all. If it isn’t caught in that time frame there can be many different reasons, it might have been just passing through or been, caught elsewhere, or it maybe on the edge of its territory and not visiting frequently. GWCT research suggests that you return the raft to monitoring mode after about 10-15 days without a capture but this is not our recent experience, these days with lower density it’s advisable to leave a trap out for longer. If you get footprints straight away after returning to monitoring mode replace the trap. We suggest keeping the trap set for an extra few days after each capture. The reason for this is the scent of the mink you have just caught is now all over the trap, this is probably the best attractant there is, especially during the mating season.

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Mink can be caught at any time of the year, but we are sometimes asked if mink are more easily caught at one time of the year than another. The simple answer is “yes” and the figure shows the relative trapping success during trapping operations. Mink are most frequently caught in late summer, when juveniles predominate, and during the mating season, when there is a tendency to catch more adult males. Perhaps relax a bit in May and June but keep a sharp look out in the spring and autumn!

 

 

 

No bait is used on the raft while in monitoring mode, when a trap is set bait can be used, however it will need to be replaced regularly to ensure it is fresh. If you want to try and bait your trap, fish should work but remember it will need replacing and what works for one mink might not for another, mink can be very individual, and it may increase the interest from non-target species. Scent lures are another option and work in the Western Isles of Scotland showed traps baited with commercial mink scent gland lure (Kishel Scents and Lures, Saxonburg, USA) caught significantly more mink than traps baited with fish. The best thing we have found is the scent of another mink; people tend to find they catch again within a few days of the first capture because the scent is left on the trap.

There can be several reasons for this but don’t jump to the conclusion that the mink is “trap shy”. Mink tracks left during late winter-early spring and autumn may have been left by ‘transient’ animals moving through the area, either to find mates or to disperse. Sometimes they might have left the vicinity by the time you come to check your raft, the option here might be to shorten the raft checking interval to give a faster response time and set traps, not only on the raft where you found the tracks, but also on any adjacent ones.

If the tracks were large, it’s possible the animal entered your trap but did not trigger it. A very large male mink might stand on the front of the treadle plate with its nose up against the end mesh, and may not take the final step before turning around and leaving the trap. Most of the time we fine tune the cage traps we supply and moving the treadle forward one square is one thing we do to help increase the chance of a successful capture.

Try turning the trap around so the entrance is at the other end, it maybe that the mink prefers climbing onto the raft at one end. Keep an eye on what directions the tracks are going on the raft, they might all be going in one direction. This indicates that it may prefer going in that end and this is the way you should first set your trap.

Where there is a lot of traffic, mink tracks may become overlaid by other animals, which can make identification very difficult. Ironically, water voles have proved to be the main culprit. This can be overcome by more frequent raft checks or moving he raft a short distance. Trapping can still proceed when mink tracks are identified, but it should be remembered that water voles can still enter that trap even with an otter guard installed and it is always essential to check a set trap at least every 24 hours. Capturing the mink is clearly a priority when there are plenty of water voles about, as this situation is unlikely to last if the mink is not trapped!