INTRODUCTION. 
viii 
remarks, it may be here mentioned that young- birds appear to wander further from their native homes 
during the first autumn or year of their existence than they do afterwards, going out, as it were, to see the 
world before settling down for the proper business of their lives ; hence, doubtless, it is, that the young of 
so many of the rarer northern species (Eagles, Gulls, Divers, &c.) are found further to the south than the 
old birds. 
With respect to the autumnal departure of many kinds of our smaller migrants, it would appear that most, 
if not all, of them assemble along our south coast ready for departure on the occurrence of a favourable wind. 
Having once crossed the Channel to France or Portugal, their further southern journey becomes an easy 
one, and is doubtless performed by short stages until they reach the shores of the Mediterranean, which in 
the case of our own birds is probably crossed at the narrowest portion, viz. Gibraltar, or some other 
promontory of Southern Spain, their destination being the coast of Morocco. On the other hand, those of 
Central Europe migrate by the way of Sicily and Malta to Algeria, while those which have passed the 
summer still further east proceed in a direct line to Egypt. North and south, and vice versa^ is in my 
opinion their instinctive movement ; and this natural impulse is so blindly followed that the Quail, when 
migrating, will, if possible, fly through a house or over a mountain rather than turn aside from its course, 
which would not be the case were reason its guide ; in this respect it resembles the Norwegian Lemming, 
whose onward course is stopped neither by lakes nor hills, and some species of ants, whose movements are 
equally undeviating. 
The British Islands and Europe generally, however, to which the foregoing remarks on migration almost 
solely refer, are not the only portion of the globe subject to such interchanges of bird-life at different 
seasons of the year ; the avifauna of the great continent of Asia, a continent having the loftiest mountains, 
the most elevated plateaux, and the richest forests in the world, exhibits similar phenomena. So, again, if we 
cross the equator and take a view of what occurs in the southern hemisphere, we shall find that a precisely 
analogous movement takes place there, but of course at opposite seasons, the antipodean summer being 
coincident with our winter. In many instances bird-life is there represented by species of a similar form to 
those we find in our own country, and which evince a tendency to a movement north and south at certain 
periods of the year as with us. 
Although in the foregoing remarks I have used the terms migrant and migratory in their ordinary 
acceptation, it will be as well before quitting the subject of migration to place before my readers wbat I 
consider should be the strict meaning of the word migrant. The country a bird resorts to for the propa- 
gation of its species should be regarded as its true habitat : thus the Swallows and others, although they 
pass only half the year in the British Islands, are really not migrants in the same sense of the term as that 
in which we should so regard the Fieldfare and Redwing, who, although resident with us during the winter. 
