I46 Allen, Gatkes 'Heligoland.' [ April 



which have been detected in Heligoland only once each, in a 

 period of fifty years, and half of the remainder but twice each ! 

 Furthermore that in many instances these records are spring 

 records, the species having never been taken in Heligoland in 

 autumn. A further examination of the list shows that not more 

 than one-third of these 396 species are really in evidence as regards 

 the autumnal migration. Notwithstanding this misleading state- 

 ment as to the extent of the evidence, we cannot suppose that 

 Gatke is mistaken in regard to the order of appearance of the old 

 and young birds at Heligoland after the breeding season in the 

 case of such familiar species as the Starling, the Wheatear, the 

 Pied Flycatcher, the Whinchat, the Redstart, Willow Warbler, the 

 Ortolan Banting, etc., the young of which are reported as appear- 

 ing in Heligoland from the last of June or early part of July 

 onward till September, weeks in advance of the old birds. As 

 these birds all breed commonly on the adjoining mainland, it is 

 doubtful whether these early visits of young birds indicate any- 

 thing more than local movements of young birds prior to the 

 season of true migration. As only one land bird, the ubiquitous 

 House Sparrow, breeds regularly in numbers on this little unfor- 

 ested island, any visitors from the neighboring mainland after the 

 breeding season appear to be entered in Mr. Gatke's list of fall 

 migrants. Indeed it is evident that these young birds, only a 

 few weeks from the nest, must be many of them still in nestling 

 plumage, and hence unfitted to start on their regular autumnal 

 migration. 



The case, however, is different with the young Golden Plovers 

 (Charadrius pluvialis) recorded as arriving at Heligoland the first 

 week in July, since the breeding grounds are more distant. It 

 goes to show, however, that allied (congeneric) species of birds 

 may behave very differently at different places, for it is a well 

 established fact that on the eastern coast of North America the 

 adult birds arrive first in the case of the American Golden 

 Plover. 1 Also it is almost the uniform testimony of our best 

 American observers that as a rule, among song birds as well as 



'See especially Mackay. Auk, XIII, 1896, pp. 90-92; also Feilden, Ibis, 

 1889, p. 491. 



