150 ALLEN'S NATURALIST'S LIBRARY. 



ground-colour is white or faint greenish-white, and the eggs 

 arc often quite uniform, or show faint spottings or marblings of 

 pale rufous. On the other hand, they are sometimes richly 

 marked and clouded with rufous or rufous-brown. Every 

 gradation in a series of clutches is exhibited in the Seebohm 

 collection in the British Museum, from unsullied white eggs to 

 those in which the ground-colour is almost hidden by a con- 

 fusion of mottlings and cloudings of rich chestnut or rufous- 

 brown. Axis, 2*i-2'4; diam., i"j-i'g. 



II. THE DESERT BUZZARD. BUTEO DESERTORUM. 



Falco desertorum, Baud. Traite, ii. p. 164 (1800). 



Buteo desertorum, Sharpe, Cat. B. i. p. 179 (1874) ; Dresser, B. 

 Eur. v. p. 457, pi. 332 (1875) ; Seebohm, Br. B. i. p. 122, 

 note (1883) ; B. O. U. List Br. B. p. 94 (1883). 



Adult Male. Smaller than B. buteo, and much more rufous, 

 especially on the upper tail-coverts and tail ; the bars on the tail, 

 nine or ten ; cere lemon-yellow ; bill dark lead-colour, lighter 

 near the throat and cere ; feet lemon-yellow ; iris light hazel 

 or yellowish. Total length, 21 inches; culmen, 1*55; wing, 

 13-4; tail, 7-8; tarsus, 3-0. 



Young Birds. Much paler than the adults, especially on the 

 under surface, the tail always showing a rufous tint, and having 

 as many as thirteen bars. 



The rufous character of the plumage of this Buzzard is the 

 best test for recognising it from the Common Buzzard, but it 

 is sometimes very difficult to distinguish the two species, as 

 B. desertorum gets very dark in its older stages, while B. buteo 

 not unfrequently exhibits a shade of rufous on the tail. 



Range in Great Britain. The present species has been sup- 

 posed to have occurred three times in England : twice in North- 

 umberland, and once at Everley in Wiltshire, where a speci- 

 men was shot in September, 1864. The two Northumbrian 

 birds may have been wrongly identified, but the Wiltshire 

 example was considered by the late Mr. J. H. Gurney to be an 

 undoubted Desert Buzzard. 



Range outside the British Islands. This species occurs in the 



