1S97.] PAI.MKR. — The Migration of Birds. 19 



The spring emigration from Great Britain to the Continent 

 begins early. In February, in some seasons, Geese begin to 

 move northwards, but the chief emigratory movement is the 

 departure of Larks and Rooks to the Continent by the Kast 

 and West Route. During March these movements increase, 

 when the Hooded Crow is also seen returning to the Conti- 

 nent. Emigration to the north also commences on the part of 

 the Great Grey Shrike, Shore I^ark, Swans, Geese, Gadwall, 

 Scaup, Golden Eye, Long-tailed Duck, Red-throated Diver, 

 and probably many others. In this month, too, the Green- 

 finch, Chafiinch, Twite, «&c., leave their winter retreats on the 

 west coast of Ireland. In April thirty-four species are 

 observed to leave our shores for the north, and the emigra- 

 tion by the East and West Route comes to an end. 



In May the emigration to the northern breeding-grounds 

 reaches its maximum, when fiftj^-three species are recorded. 

 Our emigrants from Britain are joined by others (some of the 

 same species as those leaving us) which have wintered further 

 south. The departure of our winter visitors and the spring 

 birds of passage takes place from the eastern coasts of Britain 

 and the northern isles. A few species only, such as the Red- 

 wing, Wheatear, White Wagtail, Barnacle Goose, Swans, and 

 Whimbrel pass up our western coasts, possibly en route for 

 Iceland. 



Special attention has been given to the actual relation 

 between migrational and meteorological phenomena. The 

 data relating to the latter are taken from the " Daily Weather 

 Reports " issued by the Meteorological Office. Tliese reports 

 are based on observations made at fifty-four stations distri- 

 buted over Western Europe. It was necessary thus to con- 

 sult the Continental as well as British weather- conditions, for 

 it is essential that the weather prevailing where the migratory 

 movements have their origin should be considered. An 

 extensive series of comparisons between the two sets of 

 phenomena shows that they are intimately associated. 



It is found that in both the spring and autumn migratory 

 periods there are spells of genial weather without marked 

 features other than those favourable to migration. During 

 these the migratory movements are of an even-flowing nature. 

 If the weather proves slightly unsettled during such periods 



