NON-INDIGENOUS BRITISH BIRDS. i6i 



of deserted Mongol villages as an occasional site ; whilst 

 it has been found amongst a colony of Griffon Vultures, 

 or near to nests of the Raven, Black Kite, and Egyptian 

 Vulture in the cliffs. Usually the nest is not far from water, 

 but instances are by no means rare in which it has been 

 found long distances from it. The nest is made almost 

 entirely of down, mixed with a few straws or bents. 



Range of egg colouration and measurement : 

 The eggs of the Ruddy Sheldrake are from eight to six- 

 teen in number, but eight or ten is the average clutch. 

 They are smooth in grain, very fragile, and creamy- 

 white. Average measurement, 27 inches in length by 

 1*8 inch in breadth. Incubation, said only to be per- 

 formed by the female, but probably by both sexes, lasts 

 thirty days. 



Diagnostic characters : The eggs of the Ruddy 

 Sheldrake cannot be distinguished from those of the 

 Common Sheldrake. Unfortunately the down of this 

 species appears not to have been described, but will 

 probably prove of some assistance in identifying the 



ecfcrs. 



Family ANATID.E. Genus Anas. 



Sub-family ANA TINAL. 



AMERICAN WIDGEON. 



Anas Americana, Gmelin. 



(British : Very rare abnormal autumn migrant.) 



Single Brooded. Laying season, last half of May, in June, 

 and possibly July. 



Breeding area : Northern Nearctic region. The 

 American Wigeon breeds in Alaska, probably through- 



M 



