234 



THE ZOOLOGIST, 



as well as in combat. In most birds of limited vocal compass 

 the distress-cry is merely an exaggeration of the ordinary call- 

 note or signal of assembly, as, for example, in the Mallard, Crow, 

 and Kook; but fear may induce in the call-note inflections 

 unappreciated by the human ear. 



It is a curious fact that among birds of limited vocal power 

 the call-note resembles the danger-cry (or alarm) much more than 

 in birds of varied song. The Mallard, Crow, Kook, and Bullfinch 

 may be mentioned as typical of the former class ; and the Black- 

 bird, Starling, Redbreast, and Nightingale as typical of the latter. 

 This tends to prove that the call-note and the danger-cry had a 

 common origin, namely (as before suggested), the cry of distress. 

 This distress-cry became modified in different species and for 

 different occasions, and developed into a cry of dismissal as well 

 as into a call of assembly. The House Sparrow utters a charac- 

 teristic note to indicate the arrival of a hawk, at the sound of 

 which House Sparrows within hearing secrete themselves. This 

 bird has another danger-signal, which is employed as a call-note 

 to the young. Several species silence their young by a note of 

 warning. I have known a Blackbird utter different notes to 

 announce the presence of a cat or a human being. The common 

 fowl (whose notes generally have withstood the influence of artificial 

 selection) utters different alarm-cries to signal the approach of a 

 dog or cat, or that of a hawk. 



It may be fairly suggested that certain alarm-notes are 

 onomatopoeic, and are intended to suggest the presence of the 

 seemingly most dreaded enemies of the bird. Such alarm-notes 

 are the "oof" of the common pigeon, — a cry which closely 

 resembles the sounds made by the wings of this bird when it is 

 swooping rapidly in play, or in its efforts to avoid the pursuit of 

 a hawk, — and the hissing sounds made by some birds of the 

 genera Picus and Parus when nesting, and which sounds are like 

 the hiss of that dreaded enemy of the nest, the snake. The hisses 

 of these birds may be employed for protective purposes ; but, on 

 the other hand, they may be merely the spontaneous expressions 

 of hatred which have been inherited from a remote ancestry. 



The distress-note was probably uttered by the males of some 

 species as a defiance-cry, and as such it would be, like the 

 "crow" of the cock, addressed to other males rather than to 

 females. Rival males of certain species, such as the Willow 



