Conserving Britain's
wetland birds
Malcolm Ogilvie
The latest annual
report of the Wetland Bird Survey (WeBS), covering the winter of
1996-97, contains a series of graphs showing how the numbers of
individual species have varied over the last 30-35 years. Looking
at these, one is struck by how many of the lines have an upward
trend and how few are heading downwards. Of 36 of the commoner species
or populations for which there is data going back to at least 1969-70,
no less than 20 have increased compared with just two which have
declined, while the remaining 14 have shown little or no change,
though some may have fluctuated in the intervening period. I should
add that I have not carried out a statistical analysis, but merely
"eye-balled" the graphs.
Good News For Wildfowl
All three species
of swans (Mute and Whooper Swans illustrated
top right) have increased, as have almost all the geese,
though numbers of the European Whitefront have declined. The dabbling
ducks have done well, too, with the slightly surprising exception
of the Mallard. However, the autumn and winter counts of Mallard
in Britain are greatly influenced by the fact that large numbers
are reared and released by wildfowl and shooting clubs so that increases
or decreases may not reflect what is happening in the wild population.
During the 1950s and 1960s,
both Tufted Duck (illustrated right)
and Pochard were increasing rapidly, coinciding with the construction
of many reservoirs and gravel pits, but in the last 30 years there
has been little change in either.
And Waders
It is remarkable
that no wader species included in the graphs has declined in numbers
in the last 30 years while some, such as the Avocet, Grey Plover
and Black-tailed Godwit, have noticeably increased and both Knot
and Golden Plover (illustrated below)
have recovered from earlier declines. (Editor's
comment: The situation for some of our breeding birds is in contrast
to these winter counts, and Dr Ogilvie will be addressing the decline
of lowland breeding waders in a future article).
A Success Story
There is no doubt
that these figures represent a considerable success story for conservation,
with the great majority of species in a very healthy state. This
has been achieved by, for example, increased protection from shooting
and disturbance and the creation of many wetland reserves. Through
this long series of counts, the two component parts of WeBS, National
Wildfowl Count scheme and the Birds of Estuaries Enquiry, started
in 1947 and in 1969 respectively, it has been possible to identify
the most important estuaries, reservoirs and lakes, and so enable
the conservation organisations to set about putting in place the
necessary measures to protect them, firstly with British, and more
recently with European, designations. The Wetland Bird Survey is
a prime example of what we do so well in Britain, harness large
numbers of enthusiastic amateur birdwatchers to provide vital information
that can be used to the benefit of the birds.
More
feature articles
| Dr
Ogilvie is a natural history writer and editor, formerly a research
scientist with the Wildfowl and Wetlands Trust, and resident
on the island of Islay since 1986. Until 1997, a member of the
'British Birds' editorial board and also one of the editorial
team which produced 'Birds of the Western Palearctic'. |
|