THE BIRDS OF HELIGOLAND 423 



225. Cuckoo [KUKUK]. 

 CUCULUS CANORUS, Brisson [Linnrcus]. 



In Heligolandish also called Kukuk. 

 Cuculus canorus. Nauinann, v. 196. 

 Cuckoo. Dresser, v. 199. 



Coucou gris. Temminck, Manuel, i. 381, iii. 272. 



Not only is the spring of Heligoland bereft of the solemn strains 

 of the Nightingale, but the merry note of the Cuckoo also has 

 been almost entirely denied to it. I have scarcely heard it more 

 than ten times in the course of upwards of fifty years, although 

 the bird is of well-known occurrence both on its homeward 

 passage and on its return voyage to its winter quarters. Their 

 roaming and restless habits, especially pronounced in the case 

 of old birds, has of course much to do with their being so 

 generally known, especially as they prefer to fly at a height 

 which will enable them to rove freely over houses and bushes. 

 Though there may be only two or three of these birds on the 

 island, these are seen so repeatedly in different places during the 

 whole day that any one, not well acquainted with the habits of 

 this species, would believe that at least a dozen of them were 

 present. 



We have frequently, in the course of this work, laid stress upon 

 the fact that, during the autumn migration, the young birds of the 

 year set out on their journey to their winter quarters from four to 

 six, or even eight weeks before their parents ; to this rule the 

 Cuckoo forms the one single exception, for in its case the old 

 birds return from three to six weeks before their young. This 

 phenomenon results from the simple fact that as soon as these 

 birds have foisted their eggs upon some other species, there remains 

 no longer anything for them to do in their summer home, and they 

 accordingly at once resume their return journey, while their off- 

 spring is being reared by the foster-parents. Hence, in the case of this 

 species, we not only have the singular phenomenon that the spring 

 migration of the old birds, which takes place in May, is succeeded 

 by their autumn migration as early as June, but also, contrary to 

 what obtains in regard to all other migrants observed here, the 

 young birds of the year do not set out for their home passage until 

 four or six weeks later, viz. from the first weeks of July until the 

 end of August. The majority of these young birds display the 

 dark slaty-grey plumage, only solitary specimens displaying the 

 rust-coloured dress. 



