30 Illinois State Laboratory of Natural History. 



numbers of white specimens, and Mr. K. M. Barnes, of 

 Lacon, 111., reports taking a whole set of white eggs.* 



The endless variation in the coloration of the eggs is 

 only equaled by the vast variation in their sizes and 

 shapes. The extreme measurements of an exceedingly 

 large series of these eggs are .62 and .79 in length, by 

 .50 and .62 in width. In the Ornithologist and Oologist 

 (Vol. XIV., p. 38), R. M. Barnes, Esq., writes: "I have 

 in my collection one 'runt' egg of this species that is 

 not larger than a pea. It measures .48 x .40. The 

 other four eggs in this set average .73 x .55. The 'little 

 fellow' is in every way as perfectly marked and formed 

 as any of its larger brothers." 



As a rule, the eggs are blunt at the smaller end ; and 

 while some are quite elongated and others approach a 

 spherical shape, probably the greater number are ovate. 

 One egg that I found in a set of four was ovate pyriform, 

 the other three being normal. 



Incubation is carried on entirely by the female, and 

 extends over a period of ten days or two weeks. During 

 incubation the male spends the most of his time ex- 

 ploring every nook and crevice in the vicinity, often 

 meeting another husband on a similar foraging expedi- 

 tion. He keeps his mate well supplied with food, but 

 should there be any spare time, he indulges in singing. 

 After the young are hatched, both birds are kept con- 

 tinually busy filling the hungry little mouths with insect 

 delicacies. After the nesting season, the birds are usually 

 found in small flocks, consisting of the parents and the 

 young, and so they remain until their departure. 



Frequently these birds are found breeding in colonies, 

 and many nests are found in a surprisingly small area. 

 In some localities there are more pairs of birds than 

 there are holes or cavities to nest in. This scarcity of 

 nesting sites is undoubtedly the cause of the large sets 

 of eggs and double nests that have been found. The set 

 of ten eggs, previously mentioned, taken by Mr. W. S. 



•Ornithologist and Oologist. Vol. XIV., p. 38. 



