Predation Control

Predation by foxes, stoats, pine martens and some bird species can cause chick mortality and breeding failures. Reducing predation rates may lead to increases in black grouse productivity, though it is not always necessary: in some areas, increases in black grouse numbers have been achieved without controlling predation.

Any effort to remove predators must also consider potential relationships between predators: removing one predator, such as the fox, may increase the number of another, such as stoat, as they have increased access to food sources because of diminished competition. There are two options to reduce predation rates:

(a) to increase the opportunities for black grouse to avoid predators, through habitat management (such as providing increased vegetation cover);
(b) to remove the predators.

Controlling predation is most likely to be effective when undertaken over a wide area, so requiring the involvement of several landholdings.

It is only legal to trap and/or kill certain predator species: fox, stoat, weasel, mink and some crow species (not raven or chough). Birds of prey (such as hen harrier, peregrine and goshawk) and pine martens are strictly protected under UK and European legislation. For more information about legal control of predation, visit the Defra website.

The use of poisons and pesticides to control birds or mammals (other than some rodent species) is strictly illegal. Also, gin traps are strictly illegal for any mammal control.

The management objectives of a predator removal programme also need to be considered. Is the aim to increase the chances of black grouse survival in an area, or is it to gain a harvestable surplus?

Fox, Vulpes vulpes. Chris Knights (RSPB Images 2003-4256-569)

Fox Foxes can have a significant impact on black grouse numbers, as they will take nesting hens in the breeding season, and broods of young, as well as adults in winter. Fox control can be achieved by lamping (shooting at night using a high-powered light to find the fox), snaring and using kists.

If snares are used, it is important to avoid catching non-target species, such as roe deer, sheep, badgers and capercaillie. Indeed, it is strongly recommended that snares are not used in forests that contain capercaillie. All snares must be checked at least once every 24 hours and a snared fox must be despatched humanely.

Corvids
Reducing grazing on moorland and in-bye land will allow the vegetation to grow taller and thicker, thus reducing the chances of black grouse nests and chicks from being detected by corvids, such as carrion crows. Crows prefer shorter vegetation, found on grazed land with a high density of livestock, so improving habitat quality may reduce crow abundance as well as their hunting efficiency. Carrion and hooded crows are the only two corvid species that are likely to reduce black grouse breeding success, as they will feed on black grouse eggs. Ravens also occur in black grouse areas, and it is illegal to trap or kill them, or to destroy their nests or eggs.

Reducing the number of crows can be achieved by shooting, using Larsen traps and cage traps, under a general licence issued by government environment departments. The terms of the general licence must be adhered to.

England general licence

Scotland - tel 0131 556 8400
Wales - tel 01248 385653

As crows are highly territorial in spring, Larsen trapping is most effective after the crows establish their territorial pairs and should continue until mid-summer, when new birds replace those killed. Cage traps are semi-permanent devices designed to catch both territorial and non-territorial crows through out the spring and summer. Their correct siting is key to success, such as in well used flight lines, near water edges and where two valleys meet. Cage traps, either small movable Larsen traps or big permanent crow traps, can be used in the spring and early summer, when black grouse are nesting. For more information, contact the Game Conservancy Trust.

Mustelids
Mustelids is the collective term for the family of mammals that includes weasels, stoats, mink and pine martens. All four species will take the eggs and chicks of ground-nesting birds, such as black grouse, although pine martens have a limited distribution and are relatively rare, so their overall impact on the black grouse population is probably small.

Stoats, weasels and mink can be controlled using spring traps, such as Fenn traps, in tunnels, strategically placed around hill ground in walls or banks, stream sides, and under piles of stones. Controlling the stoat's principal food resource, rabbit, and their availability will greatly influence the number of stoats an area can support as well as subsequent immigration. For more information, contact the Game Conservancy Trust.

Pine martens are strictly protected under the Wildlife and Countryside Act. There are special penalties for anyone convicted of trapping or killing a pine marten.

Peregrines and goshawks are also predators of full-grown black grouse. They too are protected, with special penalties for anyone convicted of trapping or killing them or disturbing or destroying their nests or eggs.