1660 U.S. NATIONAL MUSEUM BULLETIN 23 7 paet 3 



Tinbergen found that in two cases the interval between the first 

 observed copulation and the laying of the first egg was 13 days in one, 

 8 days in the other. He also states that females do not allow the 

 males to copulate after they lay the first egg. Observers agree 

 that eggs are laid during the early morning, as early as 3:00 a.m., and 

 that generally one is laid each day until the clutch is complete. 

 Watson reported 2 days between laying of two eggs at one nest. 



The spread of egg laying at anyone locality, even at high latitudes, 

 may be considerable, in some cases more than a month. Tinbergen 

 quotes Manniche's finding eggs at Danmarks Havn, Greenland, 

 from June 6 to July 18. Though eggs may be laid earlier at low 

 latitudes — mid-May in Iceland and late May in Scotland — egg 

 laying is not necessarily late at high latitudes. MacDonald and 

 I believe egg laying started at 80° N. in Ellesmere in early June, 

 certainly no later than June 10, which is earlier than many reports 

 for lower latitudes. 



The peak of egg laying appears to be mid-June in west-central 

 Ellesmere and in southern Baffin Island at the opposite end of the 

 Canadian Arctic Archipelago, but Watson found it to be late June 

 in eastern Baffin Island. Of interest also is Salomonsen's observation 

 that egg laying in Greenland averages at least a week earlier in the 

 sunny interior than on the colder outer coast. 



Data on clutch size from various parts of the species' range, sum- 

 marized by Tinbergen and by Watson, indicate that, as Lack (1947) 

 pointed out for this and other species, the average size of the clutch 

 increases with latitude. Our observations from Ellesmere sub- 

 stantiate this. Eight clutches we found at 80° N. varied from 6 to 8 

 eggs and averaged 6.8 — a significantly high sample. 



Eggs. — The snow bunting usually lays 4 to 7 eggs, but sometimes 

 only 3 or as many as 9. The ground color is greenish, pale bluish, 

 grayish, or creamy white with spots, blotches, and occasional small 

 scrawls of greenish and purplish browns such as "dusky drab," 

 "Natal brown," "olive brown," "Rood's brown," "Clove brown," 

 and black. The undermarkings of "purplish gray" or "pale Quaker 

 drab" are frequently very prominent. There is much variation; 

 some eggs will be heavily marked with scrawls, others only with spots. 

 The markings generally are scattered over the entire surface, although 

 they frequently tend to concentrate at the large end where they may 

 form a loose wreath, or make a solid cap over the top of the egg. 

 Some types are very pale and marked only with light browns such as 

 "wood brown" or "fawn color" and without undermarkings. The 

 measurements of 50 eggs average 22.9 by 16.5 mm; the eggs showing 

 the four extremes measure 264 x 17.3, 23.4 x 18.S, 20.3 x 15.8, and 

 21.3 by 15.2 millimeters. 



