190 THE BIRDS OF HELIGOLAND 



27. — Montagu's Harrier [Wiesenweihe]. 

 FALCO CINERACEUS, Montagu.^ 



Falco cineraceiis. Naumaun, i. 402, xiii. 165 ; ibid. Blasius, 



Nachtraije, 2,2,- 

 Montagu's Harrier. Dresser, v. 423. 

 Bnsard Moiitugu. Temniinck, Manvel, i. 76, iii. 42. 



This Harrier is also of very rare occurrence. Reyniors only once 

 possessed an old bird. Claus Aeuckens saw one on the 5th of 

 November 1852, and afterward.s two very pretty young summer 

 birds were shot, both of which are in my collection. The extremely 

 isolated occurrence of this species is equally surprising, since it 

 breeds, if not abundantly, in Holstein and on the Lower Weser. 

 The reason of its rarity in Heligoland is no doubt only to be ex- 

 plained as the result of an autumn migration on a rigidly confined 

 southerly line of flight. 



Heligoland is indeed a by no means inviting locality for birds 

 of the habits and mode of life of the Harriers. Hence it is 

 interesting to see how on this island each of those species manages 

 to find out the spots most suitable to its character. Thus the 

 Marsh Harrier was shot in the long sand lyme-grass {Elymus 

 arenarms, Linn.), which grows so abundantly on Sandy Island ; 

 while all the smaller species resort to the sole, insignificant piece 

 of fresh water on the island. This consists of a natural depression, 

 which stretches across the plain of the plateau. At the lower part 

 of this depression the thin layer of soil which overlies the rock was 

 removed and heaped up into a dam, a primitive kind of reservoir 

 for rain-water bemg thus constituted, which at times contains 

 several feet of water, and is about fifty paces in diameter. Almost 

 every Harrier, without exception, passes over this depression, 

 and if one happens to be seen, Aeuckens forthwith makes his 

 appearance on the spot, and usually returns successful from his 

 expedition. Montagu's Harrier breeds in temperate and southern 

 Europe and Asia, but only rarely passes across the Baltic, and in 

 southern Sweden has been seen only once or twice. Irby found it 

 nesting abundantly in Morocco, and it seems to breed also most 

 abundantly in the low-lying districts of Spain. 



Genufi Strix — The Chd. — Of the hundred and ninety species of 

 Nocturnal Birds of Prey which — according to Sharpe's statement 

 (Catalogue of Birds of British Museum) — are distributed over the 



' Circus cineracetu (Mont. ). 



