EUROPEAN WHEATEAR 293 



Eggs. — The eggs of the wheatear are a uniform, delicate, pale blue, 

 only occasionally showing some red-brown specklings. The Rev. 

 F. C. R. Jourdain (1938, vol. 12) gives the measurements of 100 British 

 eggs as: Average, 21.2 by 15.9 millimeters; maximum, 24.8 by 15.4 

 and 21.8 by 17 millimeters; minimum, 19 by 15.3 and 19.4 by 14.6 milli- 

 meters. I am not acquainted with any measurements of Alaskan eggs. 

 The normal clutch in Europe is six, sometimes five and occasionally 

 seven, but Jourdain mentions that complete sets of three or four may 

 also sometimes be found and very rarely eight. The species is double- 

 brooded on the south coast of England (Walpole-Bond, 1938) but is 

 usually single-brooded, and it seems safe to state that it must be so in 

 Alaska. In the British Isles eggs are found late in April or early in 

 May, but chiefly in May. In Germany the period is given as the 

 second half of May to June (Niethammer, 1937). At Vadso, northern 

 Norway, where the conditions no doubt more nearly approach those 

 in Alaska, full clutches were found on June 23-25 (Blair, 1936). 



Young. — Incubation is performed chiefly by the female, but Miss 

 E. L. Turner (1911) and H. L. Saxby (1874) record the male also 

 taking a share. Niethammer (1937), however, quotes a case of a 

 captive pair in which the task was performed entirely by the female. 

 Incubation begins on completion of the clutch (D. Nethersole- 

 Thompson, 1943), and the period is given by Jourdain as about 14 

 days. Caroline and Desmond Nethersole-Thompson (1942) in a de- 

 tailed survey of eggshell disposal by British birds state that the 

 eggshells are removed from the nest, though small pieces may be 

 found crumbled up in the lining. They have observed a female 

 carrying a shell and have found many shells in nesting areas. The 

 young are fed by both sexes, but according to Miss Turner, already 

 quoted, if the birds are disturbed or suspicious one member of the 

 pair, not necessarily always the same sex, may be much more easily 

 put off from feeding than the other. She records that at several 

 nests she was photographing the hens alone brought food to the 

 young, the males diligently collecting it and supplying their mates, 

 but refusing to face the camera. But she quotes a case of another 

 nest at which the photographer counted 32 visits by the male and 

 only one by the female. The feces of the young ones are carried away 

 by the parents, but when old enough the nestlings deposit their 

 droppings at the mouth of the nest hole. This is recorded on the 

 authority of Dr. II. J. Moon in a paper by R. H. Blair and B. W. 

 Tucker (1941) summarizing the results of an enquiry on nest sani- 

 tation and published information on this subject. Oscar and Magda- 

 lena Heinroth, the results of whose amazing achievement in rearing 

 most of the birds of central Europe from the egg are embodied in 

 their great work "Die Vogel Mitteleuropas" (1926), found that 



