378 THE NIGHTJAR 



round and went in another direction without flapping his wings." 

 He littered a note syllabled as " wheep." In this case, however, it is 

 not clear that the bird felt anxiety about its young. 1 



The co-ik above mentioned is the nightjar's usual note in flight. 

 It is no doubt a call-note, but what other meanings it possesses have 

 yet to be fully determined. The quik, qnik is evidently used to express 

 alarm. There is, in addition, the summoning note of the parent when 

 ready to feed the young, syllabled by Dr. Heinroth as kurrr, angli- 

 cised, kourrr. The call-note of the young is a plaintive piep, which is 

 replaced later by the co-ik. According to Mr. Selous the latter have 

 another note, which he syllables as quir. 2 The churring song has 

 already been described. Outside the breeding season, and therefore 

 after he has left our shores, the male utters a kind of gurgling note 

 (German, grollen), which he accompanies with the familiar lateral 

 movement of the tail. 3 



About the manner of the nightjar's departure in the autumn very 

 little is known. It is said to migrate usually singly, also in pairs or 

 families. 4 On the other hand, " it has been seen assembling at Flam- 

 borough previous to migrating," 5 which points to gregarious travelling. 

 Further observation is needed to settle the question. 



1 Ussher and Warren, Joe. cit. ! Zoologist, 1899, 501, where still other notes are given. 



3 Dr. Heinroth, op. cit. 



4 Naumann, Vogel Mitteleuropas, iv. 247 ; Fatio, Faune de la Suiase, ii. 272. 

 6 Nelson, Birds of Yorks., i. 260. 



