I20 



NOTES ON THE BLACK-HEADED GULL IN 

 ESSEX IN igoi. 



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 imperceptil^le 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 the}' 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. 



