Control of Grey Squirrels
BEFORE CONSIDERING TRAPPING GREY SQUIRRELS MAKE SURE YOU ARE AWARE OF THE LEGAL IMPLICATIONS!
• Kill traps and poison must not be used to control grey squirrels in areas where red squirrels may be present, as it is an offence to intentionally kill or injure a red squirrel.
• It is an offence to release a grey squirrel into the wild, and therefore any grey squirrels trapped must be destroyed humanely.
• Traps must be checked at least once a day, and any trapped red squirrels released immediately.
For further information on legislation, contact Scottish Natural Heritage.
The grey squirrel was introduced into Britain in the late 19th century (from 1876 onwards), and has replaced the native red squirrel in most of its former British range. Red and grey squirrels occupy the same ecological niche, as they are both small tree-dwelling mammals that rely on similar food sources (tree seeds, nuts, berries, etc). However, because of differences in their ability to digest large seeds from broadleaved trees (such as acorns and hazelnuts), grey squirrels have a competitive advantage over red squirrels in broadleaved and mixed woodland, being able to feed on these seeds before they are fully ripe, and gain more nutritional benefit from them than red squirrels. In this way, grey squirrels out-compete red squirrels for food resources in areas where there are large-seeded broadleaved trees, resulting in weight loss and reduced breeding success for reds.
Grey squirrels are better adapted to life in broadleaved woodlands, which is why red squirrel conservation in the Borders, where there are already large numbers of grey squirrels, is associated with large conifer forests, such as Wauchope, Newcastleton and Craik, which are less attractive to grey squirrels. The continuing spread of the grey squirrel is a major threat to the survival of the red squirrel in the Borders, and in the future, Dumfries and Galloway where presently grey squirrel records are restricted to occasional sightings in areas such as Upper Nithsdale and Annandale.
The following advice on grey squirrel control has been taken from an advice note produced by the Forestry Authority Research Commission in 1994.
Different Methods Of Controlling Grey Squirrels
Research comparing the effectiveness of shooting and cage trapping shows that cage trapping (live trapping) is a more successful method of controlling grey squirrels within an area. Spring trapping (kill trapping), drey-poking and poisoning cannot be guaranteed to specifically target grey squirrels, and should never be used where there is the slightest possibility of red squirrels being present. For this reason, the use of Warfarin for grey control is prohibited in much of Scotland, including the Borders and Dumfries and Galloway. Single-catch traps are preferable to multi-catch traps in areas where grey squirrels are present in low numbers, and there may be an increased risk of accidentally trapping a red squirrel. All cage traps should have either branchwood or black plastic sheeting covering the trap, to provide some protection from the elements and minimise the stress placed on any trapped animal.
The success of any trapping operation depends on the ability to find sites for the traps that grey squirrels will visit regularly to feed. The best sites are invariably under a large broadleaved tree (eg oak, beech) and where the ground is free of vegetation. An assessment of the woodland types present on your property (a Squirrel Habitat Management Plan) can help to target grey control where it is most likely to be effective. For more information on this, please contact your Red Squirrel Conservation Officer, who may be able to do this for you, and/or provide expert advice on ideal trap locations.
Setting and Pre-Baiting
At the chosen site, level an area of ground where you want to place a trap. Lay the trap so that the wire mesh floor of the trap is flush with the ground. If possible, use a metal ‘bait tray’ attached to the bottom of the trap, to minimise the loss of bait to mice. Secure the trap by staking or pegging it down, and leave the trap with the door held open. At this stage the trap should be open but not set. Put two handfuls of yellow whole maize in the main body of the trap, and scatter several handfuls on the ground around the trap. Cover or wrap the trap with black plastic so that it is windproof, rainproof and dark inside. Secure the plastic with brashings, branches and/or stones, and camouflage the top, if necessary, with more branchwood. After two days, place more maize inside the trap and around the entrance. If the germ of any of the maize grains have been eaten out, it indicates that squirrels have visited the trap site.
After a further two days, set the trap. Check that the release mechanism is working, and place a few kernels of maize at the back of the trap and at the entrance. Re-cover the trap. Once a trap has been set, it must be visited every day, ideally 2 or 3 hours after dawn and again just before dark.
When you check the trap, remove the trap covering and immediately release any accidentally trapped red squirrels. Remove and despatch humanely any grey squirrels. This may be done either by shooting them in the trap (taking care not to shoot the trap to pieces in the process!) or by securing a hessian sack over the end of the trap and opening the door, allowing the grey squirrel to run into the sack. Close the sack and position the grey squirrel so that its head is in the corner of the sack, by guiding it with your foot. On a firm surface (ie NOT soft ground) deliver a heavy blow to the back of the head at the base of the skull. Make sure that the grey squirrel is dead and not just stunned. If you are in any doubt about destroying a trapped grey squirrel, contact your local Red Squirrel Conservation Officer who may be able to assist.
Re-set the trap by replacing maize inside the trap, checking the trap door release mechanism and setting the trap. Replace the trap covering. If there are no captive animals present in the trap, check for holes in the trap and that the trap mechanism is working properly. Again, check for signs that squirrels have been taking the bait. After 4 to 5 days of trapping in an area, if no grey squirrels are being caught, remove the trap and if necessary re-site it elsewhere and repeat the procedure.
The best time of year for trapping grey squirrels is between March and September, when their natural food is scarce. During autumn the availability of nuts, berries, fruits and cones significantly reduces the likelihood of trapping greys, with foraging activity tending to be limited on cold winter days.
This information has been reproduced from with kind permission of
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