180 THE SWANS 



We must therefore look for other points of difference. The carriage 

 of the neck is very characteristic : the mute-swan's neck is gracefully 

 curved in the shape of the letter S, while both the whooper and 

 Bewick's swans carry the neck stiffly upright, so that a wild bird 

 can be distinguished at a great distance by this character. 



There is not much difference in size between a whooper and a 

 mute-swan, but the third species, Bewick's swan, is decidedly smaller 

 than either of them. Although this is obvious when the two birds 

 are seen side by side, it is by no means easy to estimate the size 

 of a swan on the wing half a mile away. Fortunately there are 

 other means by which the wild birds can be identified with tolerable 

 certainty, even at a considerable distance. The trivial name of our 

 domesticated bird calls attention to the fact that it is practically, 

 though not entirely, silent. It is true that the elder Naumann states 

 that wild individuals utter a very loud, trumpet-like note, closely 

 resembling that of the common crane, but he adds that it is not 

 heard during flight, as is the case with both the whooper and 

 Bewick's swans, and only very rarely from domesticated birds while 

 swimming. As so little seems to be known with regard to this note, 

 it is possible that Naumann may have taken the call of an unseen 

 crane for that of the swan he was watching. With regard to the other 

 notes, there is, however, no room for doubt. There is a "soft low 

 voice " as described in Yarrell, rather plaintive and with little variety, 

 but not disagreeable. Colonel Hawker printed some bars of this 

 song in musical notation, as formed with two notes, C and the minor 

 third (E flat), and describes how the bird kept working its head up 

 and down as if delighted with its own performance. Naumann also 

 distinctly states that both sexes make a sound which he writes as 

 "kgiurr" or "keiorr," in different tones, that of the male being 

 deeper than that of his mate. 1 An angry hissing noise is also 

 frequently heard when the birds are disturbed at the nest, and the 



1 Evidently the same sound which Heinroth writes as " chr " : he states that it is sometimes 

 used in courtship, so it may possibly be the same as Yarrell's and Hawker's "songs." The 

 alarm-note is given by him as a sharper "chin:" 



