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NOTES ON THE BLACK-HEADED GULL IN
ESSEX IN 1901.
By PERCY CLARK, B.A.
To the casual visitor up the muddy Essex estuaries, perhaps
little annual change in their state and condition is apparent, and
yet constant forces are at work in those regions, which some-
times more or sometimes less must make their inevitable mark.
A tidal wave comes up from the North Sea, such as in
November, 1897, and swamps an island or a marsh, leaving
deposit behind which tells a tale for years after ; perhaps a por-
tion of the coast is abandoned to the ever-encroaching wave,
which has happened here and there, and the waters of the sea
in places permanently enlarged their sphere.
But even in its ordinary and normal rotation the regular ebb
and flow of the tide, carrying its volume of mud in solution, as
it overswells the tangled foreshore will by imperceptible degrees
gradually raise its level, so that the flats even recently reclaimed
and enclosed by sea walls, are already distinctly sunk below the
higher portions of the saltings that remain outside them.
This will be noticed all along the Essex coasts, and as the
sea is still gaining on those shores, and when unhindered by
artificial means, working a relentless devastation and ruin ; it
proves that on the whole the land has a tendency to sink, not-
withstanding the amount of deposit that is left after every flood.
The working of this law is perhaps seen clearest in the
Broad district of Norfolk and Suffolk, where the path of the
tidal rivers has become in this way so raised above the surround-
ing marshes that sailing along them, is like travelling on an
elevated canal
But be this as it may, the Black-Headed Gulls for the last
few years seem more and more inclined to build their nests and
breed on the stretch of saltings that border our tidal channels.
Possibly they may have found that in some places the relative
height of the saltings is increasing, and that for the present, only
abnormal spring tides submerge the higher parts.
This habit of the birds is nothing really new, for a century
ago (roughly speaking) many of the salting islands in the Essex
Rivers were even then famous as their breeding haunts,