THE LIFE OF BIRDS 145 
stance, in regard to migration. This is, of 
course, a universal instinct, since even tropical 
birds migrate for short distances from the equa- 
tor, so essential to their existence do these wan- 
derings seem. But in New England, among 
birds as among men, the roving habit seems 
unusually strong, and abodes are shifted very 
rapidly. The whole number of species observed 
in Massachusetts is about the same as in Eng- 
land, — some three hundred in all. But of this 
number, in England, about a hundred habitu- 
ally winter on the island, and half that number 
even in the Hebrides, some birds actually breed- 
ing in Scotland during January and February, 
incredible as it may seem. Their habits can, 
therefore, be observed through a long period of 
the year; while with us the bright army comes 
and encamps for a month or two and then van- 
ishes. You must attend their dress-parades 
while they last; for you will have but few op- 
portunities, and their domestic life must com- 
monly be studied during a few weeks of the 
season, or not at all. 
Wonderful as the instinct of migration seems, 
it is not, perhaps, so altogether amazing in 
itself as in some of its attendant details. Toa 
great extent, birds follow the open foliage 
northward, and flee from its fading, south; they 
must keep near the food on which they live, 
