192 THE BIEDS OF HELIGOLAND 



It would appear, accordingly, that in this instance the birds, 

 the normal migration of which is undoubtedly directed south, were 

 influenced by the prevailing conditions of the weather, or carried 

 along with the general stream of migrants, so that in this particular 

 year they, in part at least, migrated to the west, such a deviation 

 from the normal line of migration-flight occurring frequently in the 

 case of many other Eastern species. Moreover, the general geo- 

 graphical distribution of this Owl will account for its rare occurrence 

 in Heligoland: the species, in fact, scarcely extends beyond the 

 Baltic, and only isolated examples reach the south of Sweden. 



The Barn Owl inhabits all temperate and hot regions of the 

 earth. Attempts have been made to separate this species into 

 about a dozen different species, according to its lighter or darker 

 coloration, or the somewhat slight deviations which individual birds 

 present from the other members of the group ; but Sharpe who at 

 the British Museum has at his disposal for examination and com- 

 parison the largest possible amount of material is of opinion that 

 such a separation does not appear justified, and has kept all the 

 varieties and colour-stages under the old Linnean name, Strix 

 flammea. (See Catalogue of Birds of the British Museum, ii. 

 p. 291.) In this view he has also been joined by Dresser. 



With the exception of one example in my collection, all the 

 other specimens of this Owl which have been met with on the 

 island had their upper and lower parts of a dull rust colour ; the 

 grey markings of the upper parts were of a very dark colour, and 

 the small spots of the lower parts were very abundant and well 

 defined. The exceptional specimen, however, above referred to, has 

 the feathers of the head, back, wings, and tail of a beautiful light 

 and pure rusty yellow (rostgelb). The characteristic grey markings 

 are very light and thinly laid on, while the under side of the bird is 

 of quite light whity rust-yellow (weisslich rostgeib), with only a few 

 scattered, scarcely perceptible dark spots at the sides of the breast. 

 The facial disk is quite white. I regard this clean and handsomely 

 coloured specimen as a very old bird, the other individuals, gene- 

 rally of a more sombre-coloured plumage, as young autumn birds. 



30. Little Owl [STEINKAUZ]. 

 STKIX NOCTUA, Ketz. 



Strix noctua. Naumann, i. 493. 



Little Owl. Dresser, v. 357. 



Chouette cheveche. Temrainck, Manuel, i. 94, iii. 49. 



I may repeat in regard to this species, what I have already 

 stated concerning the Tawny Owl : I received a very much decayed 



