Mustelids (Mustela Species)
Savaging Our Wildlife
New Zealand has three introduced mustelid species. In descending size they are;
- Ferrets (Mustela Furo)
- Mostly ground dwelling and eat small mammals, birds, lizards and frogs.
- Stoats (Mustela Erminea)
- Avid climbers. They feed on birds, rats, mice, and invertebrates.
- Weasels (Mustela Nivalis)
- Not very common and eat birds, mice, and lizards.
- The introduction of mustelids was first proposed in 1881 to control the rabbit scourge. There were concerns expressed at the time that mustelid may seriously endanger our native fauna. Although they reduced rabbit populations, mustelids were major players in the decline and loss of some out native fauna, particularly ground dwelling birds.
- During the early 1990s it was discovered that Ferrets were carriers of Bovine Tuberculosis.
We recommend that the Mark 6 ‘Fenn’ trap is used. Fenn traps should be set in wooden tunnels made from old timber. The tunnels should be 1 metre long with internal dimensions of 20 cm wide and 17 cm high. Alternatively a ready made plastic tunnel may be purchased. The trap chain should be attached to the tunnel.
- To bait the tunnel, use fresh rabbit or canned cat food. Place the bait on the ground to one side of the trap. Try dragging the meat across the ground through the tunnel to leave a scent trail that will attract mustelids.
- The best time to catch ferrets is during the period from mid summer to autumn.
It is a legal requirement that traps are checked daily within the first 8 hours of daylight.
Handy hints for trapping
- Traps should be placed not more than 200 metres apart. Once you catch a mustelid, leave the trap set in the same place. The scent from the captured mustelid will attract others.
- These are ideal locations fro placing traps.
- Near creeks and waterways
- Hay barns
- Rabbit warrens
- Cattle stops
- Use broken eggs for bait if you specifically want to capture stoats.
Maintaining the effort
Mustelid populations recover very quickly. You must persist with control if you wish to gain long term benefits.
- Using poisons to control mustelids in New Zealand is an area of new development. Mustelids are known to have died from eating the flesh of poisoned rabbits and possums. The toxin Brodifacoum is particularly effective in this secondary poisoning of mustelids.
- A protein based paste containing the toxin Diphacinone is an option for direct poisoning of mustelids. This anti-coagulant poison is available for public use, but is must be used in tunnel bait stations.
This information is reproduced with the kind permission of Wellington Regional Council who produce the pamphlet this information is taken from.