50 THE AGE'OF 'BIRDS 



you give the female plant a pollen-bearing neighbour, 

 she will not rejoice you with the pretty, rosy, sweet- 

 tasted fruits. 



XIV 



The natural term of life in wild animals must always 

 The Age remain a difficult matter for speculation 

 of Birds owing to the obstacles in the way of obtain- 

 ing statistics. Especially must this be the case with 

 birds, owing to their mobile habits ; but there is 

 reason to believe that the average term of feathered 

 life far exceeds that of most mammals. Birds have 

 no teeth to lose or loosen ; and defective teeth, imply- 

 ing imperfect nutrition, are one of the chief agents in 

 shortening the lives of animals which cannot cook 

 their food. I have already recorded in a former 

 volume the death of a white-tailed eagle at Cairns- 

 more, which, taken from the eyrie in 1858, expired in 

 captivity, apparently of old age, in 1900, being just 

 forty-two years old. 1 It is uncertain, of course, how 

 captivity may affect the longevity of a bird of rapine. 

 The captive is protected, on the one hand, against the 

 ordinary adversities of a brigand career, famine, and 

 violent death ; but, on the other hand, want of exer- 

 cise, combined with regular meals, the very antithesis 

 of natural conditions, may well be supposed to affect 

 the health of such a bird. The Cairnsmore eagle 

 became totally blind before it died. 



The question of the longevity of birds has been 

 revived by the recent death of a cockatoo at Leith 



1 Memories of the Months. Fourth Series, p. 244. 



