THE EVOLUTION OP BIRD -SONG. 285 



the three species have a common characteristic in the soft 

 squeak which is their call-note, and, curiously, is sometimes 

 repeated as a call-note by the Nuthatch, their frequent com- 

 panion. The Long-tailed Titmouse, notwithstanding a close 

 association with the others, has not acquired one of their notes, 

 but has cries which are noticeably like those of the Squirrel.* 



In the Corvidce we have the croak of the Kaven modified to 

 "corrr" in the Crow; "caw" in the Rook; and "jack," and 

 otherwise varied, in the Jackdaw. The same character-cry, 

 " cah," is uttered by the Jay as a frequent alarm, and it occurs 

 in the Starling as an alarm to the young, and at other times to 

 indicate extreme terror. The construction of the Magpie's alarm 

 by a repetition of "cah" has been suggested. I have heard a 

 Missel Thrush utter " cah" when carrying food, apparently to its 

 young. It is a question whether the single note of which the 

 rattling alarms of the Missel Thrush, Blackbird, and Eing Ouzel, 

 and the " took-took" of the Fieldfare are composed, is not, with 

 the soft "click" of the Thrush, an abbreviation of the same 

 broad sound. 



The cries of the nestling young of the Starling and Kook are 

 much alike. In spring the male Starling calls the female by 

 repeating a loud, long-drawn, squealing note, uttered in moments 

 of the greatest vehemence, and when the female approaches. 

 This note is common to every male, and is quite distinct from 

 the general character of the song. It is closely like the migratory 

 cries of the Thrush, Redwing, and Blackbird (which cries are 

 much the same, but distinguishable), and the cry of the young 

 Thrush, and that of the nestling Blackbird. This long, plaintive 

 note is uttered by the male Blackbird when the nest or young 

 have been disturbed, and sometimes before rain in autumn, and 

 during prolonged frost. A note almost identical, seeming to 

 differ only in its lack of force, is uttered by the Redbreast upon 

 exactly the same occasions, and, in addition, sometimes before 

 song on very damp autumn days. The Redbreast appears to 

 often abbreviate this note to a short squeak, very like the 

 squeak of the Flycatcher. The rattling alarm of the Blackbird 

 is reproduced on a smaller scale (if we may so employ the 



* The retention of these cries, uninfluenced by others, may be due to 

 the gregarious habits of each family of this species. 



