282 BRITISH SEA) BIRDS: 
the German Ocean and the English Channel. The 
western districts are everywhere less favourable 
than the eastern, due partly to their much more 
isolated position, and the wider extent of the 
frontier seas. Two reaches of the British coast 
deserve special mention for the numbers of migrant 
birds that frequent them. These are the coasts 
between the Humber and the Thames, and the sea- 
board of Hampshire, Sussex, and Kent. The 
observer of migration on the coast will do well to 
bear in mind the following facts. Many birds do 
not absolutely confine their flight to the indentations 
of the coast, but fly from one headland to another, 
so that on the coasts of the intervening bays but 
little migration may be witnessed. Headlands 
appear everywhere to be exceptionally favourable 
points for observation. Rock-bound coasts, again, 
are not so much frequented by migrants as those 
that are low-lying, or present a considerable area of 
beach; whilst there is some evidence to suggest 
that where the shore is composed of cliffs falling 
sheer to the water, fjords and river valleys are ex- 
ceptionally favoured. During the migration period, 
both in spring and autumn, the early hours of 
morning, or the dusk of evening, will be found 
to reward observation best. Due regard should 
also be paid to the direction of the wind, and the 
prevailing state of the weather—a change in either 
being often followed by migratory movement. 
A very large percentage of the birds described in 
