376 Roberts, Colony of Yellow-headed Blackbirds. [oct* 



revealed the fact that in almost all, if not all cases, this was due 

 to faulty workmanship or poor judgment in selecting a site. Either 

 the material was not wet enough, making it impossible to handle it 

 satisfactorily and not affording sufficient shrinkage, or it was not 

 well placed, or the reeds forming the support were improperly 

 situated so that as the nest dried it became distorted and unfit for 

 use. In one instance, it was positively determined that the same 

 bird built four imperfect nests before being able to construct one 

 that was habitable. She was closely watched for hours and as she 

 had chosen an open place in the edge of the clump it was easy to 

 observe her movements. After nearly completing one of the 

 faulty nests, this bird seemed suddenly to become aware that it was 

 a failure and in the savage manner in which she tore out the inside 

 and pulled to pieces the rim, displayed a degree of irritability and 

 temper that would have done justice to the average human artisan 

 under similar circumstances. To make matters worse, she began 

 at once the erection of another domicile some fifteen feet away, 

 using the nearly dry material pulled from the despoiled nest. This, 

 of course, she found impossible and although she tried later to carry 

 on the work with wet material this nest, also, was a failure. 



A skillful, industrious bird would build one of these large beauti- 

 fully woven and lined nests, all complete, in from two to four days. 

 Of twenty well built nests, nine were finished in two days, nine in 

 three days and two in four days. It never ceased to be a source of 

 astonishment how these bulky, well made structures could spring 

 up almost over night when it was considered that a single bird had 

 not only to collect but skillfully manipulate all this large mass of 

 material. 



Thirty-six of the sixty-two nests begun were completed and 

 received eggs. In only twenty-six of the thirty-six was the whole 

 clutch laid. From one to five days was allowed to elapse after the 

 completion of the nest before egg-laying began. The eggs were 

 invariably deposited one each day. Of the twenty-six completed 

 sets, there were two sets of three each, twenty-two sets of four each, 

 and two sets of five each. 1 In one instance, a Cowbird's egg was 



!The writer in a large experience has never found a set of six eggs, although this 

 number is sometimes given by authors. No detailed description of the eggs is 

 given here, as that formed no part of the present study. 



