Causes of decline Fences
Deer fences
The increase in deer
numbers in Scotland has led many landowners to exclude them from forests,
both native woodland and conifer plantations. Although fenced exclosures
may provide good brood habitat, collisions with poorly located deer fences
(and some stock fences) can cause significant mortality for black grouse.
Flying through the forest at first light, it is difficult for black grouse
to see these wire fences until it is too late. In a study of 80 kilometres
(50 miles) of fencing in native pinewood in the Scottish Highlands, one
black grouse 'strike' was recorded every 2.5 km (1.5 miles)of fence each
year, and at least one black grouse was killed along every 14.7 km (9
miles) of fence (Baines and Summers
1997).
What can be done?
Fences kill many birds each year, especially
black grouse (such as this female) and capercaillie. S. Taylor, RSPB
Images
Stock fences
Lower in height than deer fences, these are used to exclude sheep from
woodlands, moorland or simply neighbouring land. They have been used for
many years in the uplands, though this use may have increased in recent
years because of agri-environment schemes. Black grouse can fly into stock
fences and these collisions are frequently fatal. Although this has not
been quantified, it is believed that this can be a serious problem when
creating suitable habitats for black grouse where populations are already
low.
What can be done?
Overhead power-cables are also potentially lethal obstacles to low-flying
black grouse, while elsewhere in Europe, ski-tow and ski-lift cables are
known to kill birds (Miquet 1990).
However, since there are so few ski resorts in Britain, this is not considered
to be a serious problem here.
Other factors in the decline
Agriculture
Deer
Forestry
Predation
Shooting
Weather
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