By Hugo Straker and Mike Swan, GWCT Advisors
DOC trap (left) and Tully (right) are two options for stoats
from 1 April 2020.
Stoats are a widespread and common predator of gamebirds and many other ground-nesting species, and are widely trapped by gamekeepers, using the system known as tunnel trapping. Even where they are not a specific target, stoats may well enter traps set for other species such as rats and grey squirrels.
1 April 2020 heralds ‘all change’ to the practice of tunnel trapping throughout the UK, and the change will likely have most impact where wild game populations are being managed, with its inevitable emphasis on stoat and weasel control. Landowners, managers and keepers must all embrace this change – like it or not.
The 2018/19 Spring Traps Approval Orders for England, Scotland, Wales and Northern Ireland formalised the end of the historically popular Fenn-type spring traps (amongst others) for stoat control. As of 1 April 2020, these must be replaced with a new generation of traps, which have been approved by Defra for stoat capture. These currently include the DOC trap series (150, 200 and 250), Tully trap and Goodnature A24 stoat and rat trap. All have been designed to minimise suffering by killing target species rapidly within a specified time frame.
Regardless of trap type, each must be deployed in a way that minimises the risk to non-target species. Approved stoat traps must still be used in tunnels “suitable for the purpose”, and in the case of the DOC series, there are particular specifications that are part of the approval (see below). A range of materials can be used for this, and in the case of ‘rails’ set over ditches and watercourses, weldmesh ‘tunnels’ are still allowed to reduce flow resistance if traps and tunnels are submerged during a flood. In this case 25mm square weldmesh should ideally be used for tunnel construction to help minimise the risk of non-targets being caught by pushing a foot through from above. The tunnel, whether run-through or blind-ended and baited, must also have excluders at the entrance(s) to deter non-targets.
In the case of DOC traps, tunnel construction must adhere to manufacturer’s guidelines; choice of materials can be flexible, but positioning of traps in relation to the baffles must be according to the DOC trap instructions, as presented to the UK by the New Zealand Department of Conservation in January 2019. (The DOC trap instructions currently listed on the CMI Springs website are incorrect. For the time being please use the version available through the above link to the SASA website.)
DOC tunnels demand an outer excluder as well as an inner baffle, both equipped with appropriately sized apertures. The GWCT recommends that trappers targeting stoats and weasels stick to a 51mm diameter core-drilled or 50x50mm weldmesh aperture for both baffles and excluders. For trappers targeting grey squirrels (and rats), it may be necessary to expand the excluder aperture. For grey squirrel control, we recommend a week-long pre-baiting campaign in woodland using whole maize, and if DOCs are to be used for grey squirrel control, then these must be in a single-entry housing in accordance with the manufacturer’s UK DOC trap instructions.
Designs for Tully tunnels are up to individual operator discretion but must minimise the risk of non-target capture; again, we recommend a 50mm aperture for excluders.
Positioning of traps in tunnels is also important and will determine the length of each tunnel. Traps need to be kept far enough back from the entrance to minimise the risk of non-target capture by paw, claw or beak; we recommend 130-150mm back from the entrance. For example, with a DOC 150 trap placed in the middle of a run-through tunnel, the total tunnel length will then be at least 470mm (18½”). A Tully trap housing would need to be 100mm longer.
Where red squirrels and ring ouzels are present, we strongly discourage the use of rail traps. Trappers should always carefully assess the risk of non-target capture, as there are some areas where the risk is higher and red squirrels seem naturally drawn to rails; particularly those set across waterways. Under the Wildlife and Countryside Act 1981, as amended, it is illegal to set any trap likely to kill or cause bodily injury to any wild animal in schedules 5 or 6, which includes red squirrels. Continued use of rail traps in or close to red squirrel woods could jeopardise future use of rail traps as part of a legitimate predator control programme. If in doubt, do not set a kill trap.
Using Fenn and bodygrip traps after 1 April 2020
The popular Fenn-type trap and the BMI bodygrip will remain legal for weasels after 1 April, but trappers must reduce excluder apertures on any boxes/rails that house these traps to minimise the risk of stoat capture. Because of the overlap in body size between weasels and stoats, it is very unlikely that a physical excluder can be devised that will allow weasels to pass through while excluding stoats. We therefore urge trappers to fully embrace change and demonstrate full compliance with the law by switching to new generation stoat traps for both species.
The old traps will also remain legal for rats and grey squirrels, but there are surely very few situations where a keeper can target these species in full confidence that there is no risk of catching a stoat. Trapping in the roof space of a house might be an exception, and bear in mind that stoats will enter barns and farm buildings. They are also good climbers, so even grey squirrel traps in purpose-built boxes sited in trees remain a grey area, and anyone who takes a chance is surely at risk of becoming a test case.
This change to trapping will likely mean fewer traps being deployed due to the expense of new approved stoat traps. Whilst the extra cost may challenge some shoot budgets, we encourage trappers to embrace these new humane traps and learn how to incorporate them into their predation control strategies.
Our FAQ on the implementation and consequences of the Agreement on International Humane Trapping Standards (AIHTS) can be found here.