1903 The Language of Birds 103 



farmyard hen will assault and drive off a dog which has 

 frightened her chicks and made them call out. The note of 

 distress (4) is common to the foregoing class, and also to 

 gregarious birds, such as sparrows and starlings, because 

 these birds will often assemble to beat off an enemy when 

 they hear a companion in distress. It would be interesting 

 to know whether there is any difference in this respect 

 between the young rook and the young carrion crow. The 

 note of menace (5) seems peculiar to those nestlings which 

 are reared in holes, like barn-owls and starlings, and is no 

 doubt useful sometimes in scaring away intruders ; and it 

 can do no harm, because the young have no other means of 

 escape. Young birds in open nests, from which they can 

 scramble as a last resource, are silent when danger threatens, 

 and thus often escape unnoticed. Lastly, so far as the 

 young are concerned, there is (6) the note of content, 

 which is uttered by chickens when they nestle under their 

 mother, and is presumably characteristic, like the note of 

 fear, of the young of parents who can fight to protect them. 

 Otherwise it would be better for the young to keep quiet, no 

 matter how happy they may feel. 



Passing now to the notes of adult birds, we have first 

 those sounds which are uttered by parents to their young. 

 They are three in number. There is the special call to the 

 young (7), which appears only to be used, as indeed one 

 might expect, by those birds whose young can run or swim 

 immediately after they are hatched. We are familiar with 

 this note of the hen and the swan, the redshank and the 

 partridge. Then there is the note of warning to the young 

 (8), which is best observed in the case of the song-thrush. 

 So long as the parent repeats this note, the young thrush 

 which has just left the nest will hardly stir, even when your 

 hand is raised to seize it. The third note used by parents 

 to their young is one of domestic content (9), typified by the 

 crooning note of a hen brooding her chickens. You may 

 hear a partridge use it too; and it seems characteristic of 

 those parents which can fight in defence of their young. 

 Prudence keeps others silent. 



Next we have an interesting group of four notes used by 

 adult birds to their mates. The note of courtship (10) is 



