The Birds’ Calendar 
up another partner with surprising and almost 
unseemly celerity. 
A bird’s natural period of life appears to be 
somewhat, though by no means strictly, pro- 
portional to its size. Vital statistics of such 
fugacious creatures are difficult to obtain, and 
afford only approximate conclusions. It is 
known, however, that eagles and swans some- 
times live a hundred years, whereas, for many 
of the smallest species the limit is only five 
or six years. Peacocks not uncommonly live 
twenty years, and even goldfinches and _ black- 
birds have attained that age, although probably 
it is greatly in excess of their natural limit ; and 
parrots have survived sixty years in confine- 
ment. Doubtless, the average duration of bird- 
life, as fixed by nature, does not exceed ten or 
twelve years. 
Yet, naturally short-lived as are the great 
majority of birds, vast numbers are prematurely 
cut off by adverse climate and lack of food, by 
the ravages of disease, by the attacks of numer- 
ous insidious foes among the lower animals, 
and, most lamentable of all, by the wanton as- 
saults of man himself. It is disgraceful to hu- 
324 
