130 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



holes of trees like Kestrel. Eggs. — Almost always 4-5, but 6 said 

 to occur. Smaller than those of Kestrel and similar in type of 

 colour and markings, though often more boldly marked. 100 eggs 

 average 36.8 X 29.2. Max. : 41.5 x 30.5 and 40 X 32. Min. : 

 33.8 X 29.4 and 36.5 x 27.3 mm. Breeding -season. — Rather late : 

 latter part of May and early June. Incubation. — Male has brooding 

 spots and takes part in incubation. Period not precisely known. 

 Single brooded. 



Food. — Mainly insects, coleoptera (Melolontha, Cicindela, etc.), 

 odonata (dragon-flies), orthoptera (grasshoppers, locusts, mole- 

 crickets, etc.) and hymenoptera {Apis). Occasionally also small 

 mammals (mice and shrews), also small birds, frogs and lizards. 



Distribution. —British Isles. — Rare vagrant. About thirty -six 

 England, chiefly south and east, but also Cornwall, Salop, Cheshire, 

 Lanes. Two Wales (Pembroke and Denbigh). Four or five 

 Scotland (Aberdeen (two or three), Fife, and Roxburgh). One 

 Ireland (Wicklow). Most spring and summer, a few autumn, and 

 exceptionally winter. 



Distribution. — Abroad. — Breeds in Russia and west Siberia as far 

 east as the Altai, and in Hungary and the plains of the Lower 

 Danube ; migrates in winter to Africa. Accidental Holland and 

 Canaries. Replaced by a paler form in east Siberia (which winters 

 in the eastern parts of India) and north China. 



Family AQUILID.E. 



Vomer not touching maxillo-palatinum, without oval swelling. 

 No spina interna. Prsecoracoid not touching claviculum. Eggs 

 spotted or unspotted. Containing Eagles, Buzzards, Sparrow - 

 Hawks and allies, Kites, Harriers, Vultures and the very different 

 Osprey, latter generally put in a special subfamily. Many genera. 



Genus A QUI LA Briss. 



Aquila Brisson, Ornith. I, p. 28 (1760 — Type by tautonymy and general 

 consent : " Aquila," i.e. the Golden Eagle, according to p. 419). 



The real Eagles, large birds with free, ear-shaped or round large 

 nostrils. Bill strong, not with sharp but with flat, rounded 

 " tooth," and without corresponding notch on lower mandible. 

 1st primary much shorter than 2nd, generally 4th and 5th longest, 

 the outer 5 primaries or more deeply emarginated on inner webs. 

 Tarsus feathered to toes, tail rounded. Eggs greenish if held 

 against light. 



Key to species of genus Aquila. 



Nostrils longer than broad, larger bird, wing 



over 560 mm A. chrysaetus, p. 131 



Nostrils round, smaller bird, wing under or not 



over 560 mm A. clanga, p. 135 



