180 , UABITS OF BIRDS. 
cuckoo, their foster nursling, and supply him with 
food long after he can fly about, whenever they hear 
his cuckooing, which Linneus tells us is his call of 
hunger.* And all our domestic animals are readily 
taught to come to us for food when we use one 
tone of voice, and to fly from our anger when we 
use another.” 
Those who have attended minutely to the lan- 
guage of fear, alarm, or defiance among birds, can- 
not fail to have remarked the considerable variety 
both of notes and intonation in the same species. 
Thus, as White of Selborne remarks, ‘ when the 
hen turkey leads forth her young brood, she keeps 
a watchful eye, and if a bird of prey appear, though 
ever so high in the air, the careful mother announ- 
ces the enemy with a little inward moan, and watch- 
es him with a steady and attentive look; but, if he 
approach, her note becomes earnest and alarming, 
and her outcries are redoubled.”t In the instance 
of a male bird expressing fear or giving an alarm 
to the hen of the approach of danger near the nest, 
the tones seem to be varied so as to give her due 
notice either to keep close and still, or to make her 
escape with as much caution as she can. ‘ This 
note,” observes Mr. Syme, “ is only comprehended 
by birds of the same species, though we have cer- 
tainly seen birds of different genera appear as if 
alarmed by this note of fear sounded by a bird of a. 
different species or genus; but whether it was the 
note that alarmed them or our presence, we can- 
notsay. But we are pretty sure the notes of parent 
birds and the chirp of their young are only under- 
stood by birds of the same species, or, rather, we 
should say, same family, for it appears to be a fami- 
ly language, understood reciprocally by parent birds 
and their young: for the young know the notes of 
the parents, and the parents those of their own 
* Syst. Nat. + Letter 85. 
