NON-INDIGENOUS BRITISH BIRDS. 117 



accumulated there. The bird is a close sitter, like all 

 hole-building species, and generally allows itself to be 

 taken from the nest. 



Range of egg colouration and measurement : 

 The eggs of the Scops Owl are five or six in number. 

 They are somewhat rotund in shape, smooth in texture, 

 and pure white. Average measurement, 1*25 inch in 

 length by ro5 inch in breadth. Incubation is performed 

 by the female, but the duration of the period is apparently 

 unknown. 



Diagnostic characters : There is no reliable cha- 

 racter by which the eggs of the Scops Owl may be 

 distinguished from those of the Little Owl (the only 

 European species with which they can be confused) : 

 they are a little smaller on an average, more globular, 

 and the grain is perhaps a trifle finer. 



Family STRIGID^. Genus Bubo. 



Sub-family BUBONIN^. 



EAGLE OW L. 



Bubo maximus, Gerini. 



(British : Rare nomadic winter migrant.) 



Single Brooded. Laying season, March and April. 



Breeding area : Palaearctic region. The Eagle Owl 

 (typical form) breeds throughout Europe in suitable 

 localities from Scandinavia and Northern Russia south- 

 wards to the Mediterranean, and beyond that sea in 

 Africa north of the Atlas. East of the Ural Mountains 

 in Siberia, Persia, Afghanistan, the Himalayas, and 

 Turkestan, a pale race of Eagle Owl is found {B. sibiricus) ; 



