AN ORNITHOLOGICAL LECTURE. 9^> 



scarcity of suitable food, not only for themselves, but also 

 for their young; as the food of birds at that time is often 

 very different from their ordinary diet, it requires a close 

 acquaintance with them to prophesy confidently what birds 

 would be likely to be found breeding at a given point. 



But few birds remain in the same region all the year 

 round. Out of about two hundred and seventy-five spe- 

 cies occurring in New England or New York in June, only 

 twenty-five or so stay throughout the year ; of these forty 

 or fifty come to us in winter only, leaving us two hundred 

 and twenty-five species of spring birds, half of which num- 

 ber merely pass through to their northern breeding places. 

 With this disparity, no wonder that we look for the return 

 of the birds, arid hail with delight the bluebird calling to us 

 through clear March mornings, the velvet-coated robins, the 

 battalions of soldierly cedar-birds, the ghostly turtle-doves 

 sighing their surging refrain, the pewees, and thrushes, and 

 golden orioles, till at last, amid the bursting foliage and 

 quickness of May life, a full host of brilliant choristers 

 holds jubilee in the sunny tree-tops. 



In a very few days, as suddenly and mysteriously as they 

 came, half the gay company has passed us, going farther 

 north to breed. Could we follow this army, we should find 

 it thinning gradually, as one species after another found its 



