322 BIRD BEHAVIOUR 



nor do the Mandarin and Carolina Ducks as a rule 

 equal the length of life of the Mallard, which is 

 itself less long-lived than the Muscovy. 



Fowls are usually not allowed to live long, but I 

 have seen a hen which, I was told, was twelve years 

 old she certainly looked it ; and I have also seen a 

 Bantam-cock of seven, which, though elderly- 

 looking, had sired chicks the year I made his acquaint- 

 ance. The historical game-cock who killed the 

 fox, also, was three years old at the time, and was 

 winning contests with his own kind at six years. 

 It would be interesting to know how long Hum- 

 ming-birds live, and Mr. Ezra's two specimens have 

 given us spme information ; at the time of writing 

 he had had them a year and a half, and they were 

 adults when received, so that at any rate these 

 birds are not short-lived like insects, as many 

 people seem to think they should be. 



They do, however, resemble insects in becoming 

 torpid when exposed to cold, and those species 

 which range to Canada, Alaska, and Patagonia 

 presumably undergo this torpidity regularly every 

 night in spring and autumn ; Gould's pair of the 

 Ruby-throat (Trocbilus colubris) certainly did so 

 when on board ship in cold waters, but this may 

 have shortened their lives, as one died in the 

 Channel and the other on reaching London. Very 

 young birds, whether nestlings or chicks, also 

 become torpid when exposed to cold. 



Generally speaking, the temperature of birds is 

 exceedingly high, and maintained under all cir- 



