870 
BIRD-LIFE. 
It is the true “passage” which robs us of our field and 
woodland pets, bringing them hack again to enliven and 
populate our lakes, ponds, brooks, and meadows; those 
pretty creatures, whose numerous joys and sorrows we 
share with them, alike at their departure and return. 
The number of birds of passage is very great; we may 
say that more than half the birds of Europe are 
migratory. Great and small, birds of prey and songsters, 
water-, marsh- and land-birds, granivorous, insectivorous 
and carnivorous, are alike influenced by this singular 
desire, and experience the same necessity to quit their 
impoverished fatherland before it is thoroughly denuded. 
Almost every family of European birds has migrated by 
the winter, the birds of prey following their weaker 
brethren. 
The act of migration stands, in a certain way, connected 
with the business of breeding and the moult; the sooner 
the first is finished the sooner the bird takes its departure. 
Thus the “ passage” of birds takes place under conditions 
the very reverse of many fish; take, for example, the her¬ 
ring ; for the last migrates to spawn, while the first do so 
after they have bred. If circumstances cause delay in breed¬ 
ing the departure takes place later in the season. Many 
species remain in the North only so long as the business 
of breeding requires; others leave unwillingly, and soon 
return. Those birds which leave earliest return the 
latest; those which are the last to quit come back the 
soonest. The distance to be traversed has, however, 
nothing to do with what we have just stated, at least not 
always. Many birds go away early, and yet remain in a 
neighbouring zone; others, again, leave us later, and 
seek more distant lands. The seasons of the “ passage” 
of most birds are those of the equinoxes. 
