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Birds of tidal mud and sand flats
Wintering bird populations are often the most obvious visible manifestation
of the productivity of a wetland system. There are also many resident species
which may rely on the estuary for food whilst breeding inland. The number of
wintering and passage waterfowl using the tidal sand and mud flats within estuaries
and other tidal embayments in the UK is illustrated below. Species include a
variety of waders such as he dunlin and knot and geese including the brent goose.
These and many other species reach internationally important numbers.
Caption:
Numbers of birds using the larger estuaries in the UK. The figures represent
5 year peak monthly counts for the winters 1889/90 - 1993/94 compiled from figures
given in "An Inventory of UK Estuaries" for south west Britain; north
west Britain; north and east Scotland; eastern England; southern England and
Northern Ireland (Davidson &
Buck 1997).
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General guidance: Birds are not the only users of tidal areas.
A range of other species occur, including sea fish using the shelter of
the estuary to spawn or as nursery areas. Some species of fish (diadromous)
use the tidal waters as transitory area between freshwater and the open
sea.
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References
Davidson, N.C. & Buck, A.L.
1997.
An Inventory of UK Estuaries: Introduction and Methodology.
An Inventory of UK Estuaries
Joint Nature Conservation Committee.
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