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Factors affecting the survival of
Birds of Conservation Concern
by David Leech |
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| 5.2
Human-related factors |
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5.2.1
Hunting |
| Hunting of birds in the UK and Ireland is generally restricted to
waterfowl and gamebirds, although some raptors may also be shot or
poisoned illegally to protect game stocks. |
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- The increase in survival rates and consequently population
sizes of barnacle geese (Branta leucopsis), dark-bellied
brent geese (Branta b. bernicla) and European white-fronted
geese (Anser a. albifrons) wintering in western Europe
since the post-war cessation or regulation of shooting suggests
that unchecked hunting can lead to declines in abundance (Ebbinge,
1991).
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- The decreased survival rates and abundance of hen harriers (Circus
cyaneus) on grouse moors where they are illegally persecuted
also suggest that hunting can lead to population declines (Etheridge
et al., 1997).
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Barnacle geese populations
in western Europe have increased in size since hunting was controlled.
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- However, decreases in survival rates due to shooting may not
reduce the size of the population if the timing of hunting is
restricted to the autumn and winter, as is currently the case
with waterfowl and gamebirds in the UK and Ireland (Baines, 1991;
Ellison, 1991; Middleton et al., 1993). Increasing mortality
due to shooting is compensated for by an increase in survival
rates of the remaining individuals over the following winter,
possibly due to a decrease in the level of competition for resources.
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| However, many migratory species that breed or winter in the UK and
Ireland, including passerines, are subject to unregulated shooting
and trapping as they migrate through Africa and Southern Europe. |
- Tucker et al. (1990) related trends in the number of
individuals of a variety of species killed during migration by
trapping or shooting to variation in the size of their UK populations.
With the exception of the song thrush, the number of all other
species included in the study (including skylarks, goldfinches
and linnets) killed annually by hunters had actually decreased
since 1980, and was therefore unlikely to be responsible for the
observed reduction in population sizes. In addition, although
the number of song thrushes taken by hunters had increased during
the period of population decline, the majority of the UK song
thrush population is sedentary and is therefore unlikely to be
affected by hunting pressure outside the country.
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| Increased hunting pressure is unlikely to be the cause of post-war
population declines in UK bird species, as the numbers that are shot
or trapped during migration have generally decreased over this period,
and shooting of wildfowl and gamebirds is carefully regulated in order
to maintain stable population sizes. Persecution of corvids and raptors
in order to protect livestock and gamebird populations has also decreased
in the last 30 years, which may be a contributory factor in the general
population recovery experienced by these species. |
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