THE DARK-BREASTED BARN-OWL. 99 



more spotted than males of T. a. alba ; under wing-coverts washed 

 buff and spotted and feathers covering primaries with long dark 

 grey and bufT tips ; tail and wing-feathers darker, more mottled 

 at tips and with darker and more complete bars than in T. a. alba. 



Adult female. — Like male and not differing as female does in 

 T. a. alba. 



Nestling. — Like that of T. a. alba. 



Measurements and structure.— $ wing 275-305 mm., tail 115-125, 

 tarsus 55-62, bill from base of feathers 25-30 (12 measured). 

 2 wing 270-295. Primaries and rest of structure as in T . a. alba. 



Breeding-habits. — Exactly like those of White-breasted form ) 

 separate details unnecessary. Eggs. — Average of 42 Continental 

 eggs, 39.2x30.8 (Bey). Clutch seldom seems to exceed 7. Nau- 

 mann gives incubation period as three weeks, probably under- 

 estimated. Breeding -season. — Second half of April, but autumn 

 broods occasionally met with as in England. 



Food. — Very similar to that of the British breeding form. Von 

 Schweppenburg gives proportion of shrews as 30 per cent., mice 

 22 per cent., and voles 44 per cent. Altum records from 354 pellets : 

 7 bats, 1,064 mice, voles, etc., 12 Sparrows and 2 Swifts. 



Distribution. — England. — -Vagrant or irregular migrant. Few 

 occurrences can unhesitatingly be ascribed to this form : at least 

 eight in Sussex (Aug. to Nov., Feb.), three in Kent (one March) 

 two certainly Norfolk (Dec. and Jan.) and others probably (as in 

 Aug. and early Sept. 1891, when forty Barn-Owls were brought to 

 a Norwich taxidermist), one certainly Yorks. (Dec.) and others 

 probably (Oct. and Nov.), one no doubt Northumberland ; one 

 Berks. (Nov.) ; one Unst (Shetland) (Nov.). Probably also Hants, 

 and Essex. 



Distribution. — Abroad. — South Sweden, Denmark, Germany to 

 east France (where and even on the Rhine the ranges of this form 

 and T. alba alba overlap), south to Alps, Austria and Hungary. 



Order ACCIPITEES. 



Contains diurnal Raptorial birds. Outwardly recognizable 

 by curved sharp-pointed bill, cere in which nostrils are situated 

 and strong, powerful feet and claws, only found otherwise in Owls 

 (Striges). Basi -pterygoid processes absent. Sternum without inci- 

 sions. Oil-gland feathered. Lower tibial feathers elongated, except 

 in Pandion. With more or less underdown. Habits diurnal. Eggs 

 spotted red, in some cases unspotted. 



Key to genera of Order Accipitres. 



(Neck and head fully feathered .... 3 

 Neck and head, at least partially, bare or covered with 

 down 2 



VOL. II. H 2 



