84 THE NESTS AND EGGS OF 



a small area, but the birds are not gregarious, and live in 

 isolated pairs. 



Range of egg colouration and measurement: 

 The eggs of the Black-throated Wheatear are four or 

 five in number, usually the latter. They vary in ground 

 colour from pale blue to dark bluish-green, marked with 

 small spots of reddish-brown and occasionally with 

 darker brown. Usually the markings are mostly on the 

 large end of the ^^^-^ many of them confluent, where 

 they form an irregular zone, but sometimes they are 

 distributed over the entire surface. On some eggs the 

 spots run small and very dark, on others they are blotchy 

 and paler. Another type, less commonly seen, is almost 

 spotless. Average measurement, 75 inch in length by 

 •59 inch in breadth. Incubation is performed by the 

 female, but the duration of the period appears not to be 

 known. 



Diagnostic characters : The eggs of the Black- 

 throated Wheatear require careful identification, as they 

 can be readily confused with those of several allied 

 species. 



Family TURDID^. Genus Saxicola, 



Sub-fanuly TURDIN.^.. 



DESERT WHEATEAR. 



Saxicola deserti, Teuimmck. 



(British : Rare abnormal autumn migrant.) 



Number of Broods unknown. Laying season, May (?). 



Breeding area : South-western Pal?earctic region 

 and North-eastern Ethiopian region. The Desert Wheat- 

 ear breeds in the deserts of Northern Africa from Morocco 

 to Egypt and Nubia, northwards into Palestine, Arabia, 



