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earliest of birds throughout their summer area, reaching the 
British Islands during the last week in March, but are amongst. 
quite the last migrants to leave in the autumn. Whereas the 
swift and red backed shrike arrive very late in spring, not before: 
May here, and are amongst the first to travel south in the autumn. 
The number of some birds seen migrating in the autumn is almost. 
incredible. The little bustard crosses the Caucassian Steppes in 
millions. Flights of skylarks cross certain points in a scarcely 
broken stream for days and nights together. Prjevalski observed 
the needle-tailed swift in autumn passage in Mongolia passing 
overhead for an entire day almost without cessation. 
The British Islands are admirably situated for observing 
migration. They are the summer quarters of vast numbers of 
birds, the winter home of others, and are situated on the direct. 
fly-line of many that pass over them to breed further north, and 
return over them in the autumn to winter further south, only 
staying for a few days on each journey, and being true ‘birds of 
passage”? for us. They are visited by birds that fly north during 
the winter of the Antipodes, by birds that come from the far Hast, 
and not a few from America. Many rare birds that have taken an 
abnormal flight are also found on them. Many of the British 
migration reports read like romance. “ Birds striking the lights ; 
birds in countless hosts, drifting by in feathery tides; birds in 
hundreds exhausted and falling into the sea to perish, or allowing 
themselves to be taken by the hand; birds passing for days 
together, literally square miles of them; birds by day and birds 
by night, flying in regular steady waves or in bewildering rushes; 
birds following the rays of revolving lamps, or hurling themselves. 
against the dazzling beacons to die, or settling in crowds to rest!’ 
The most important highways of migration in the British Islands 
are always the coast lines, especially along the east and south 
coasts, draining a considerable migration from Scandinavia by way 
of the Shetlands and Orkneys. Land birds skip most of the great. 
indentation of the coast, flying from one headland to another. 
The valleys leading from the Humber and the Wash are favourite- 
routes to the interior. The goldcrests, that come in autumn 
sometimes in great rushes, may be traced up the valleys of the 
Don, and Sheaf, and Trent, almost to their sources. The song 
thrush and various waders and crows follow a similar course, 
Birds seem to prefer entering and leaving a country by a low-lying 
coast, and not by high cliffs. The Dart valley is a favourite route 
for cuckoos, warblers, redstarts, and flyecatchers, returning in spring. 
The commencement of migration in the British Islands is most. 
noticeable in February, when various birds that have been winter- 
ing here begin to pass towards the continent, especially blackbirds, 
