Jan., 1907 



NESTING OF THE PINE SISKIN IN CALIFORNIA 



19 



chosen was almost invariably about six or eight feet from the trunk of the tree and 

 upon the top of a good, strong, leafy limb. The nests were well built, quite com- 

 pact, and slightly larger than those of the green-backed goldfinch whose nesting 

 the siskins' closely resembles. Nests were constructed of dry roots, grass and leaves 

 from under the cypress trees, and were generally ,tho not always, lined with considerable 

 hair. The nests were always of the same material and could be distinguished at 

 sight from nests of the western chipping sparrow, California purple finch, and 

 wallow goldfinch, all of which birds were sometimes nesting within a few yards of 

 one another. 



The nesting season runs from the second week of April to the first of July. 

 The earliest set taken was on April 10, 1904, and the latest was a nest containing 

 one fresh egg on June 10, 1906. This same nest contained two very young birds 

 on June 24, two weeks later. A siskin was also seen carrying grass into a cypress 



TVPICAl, NKSTING SITE Oh PINK SISKIN- 

 SAN MATEO COUNTY, CALIFORNIA 



on June 24, and while this seems to point to nesting on into July, such instances 

 are undoubtedly exceptional. The height of the nesting period, however, is from 

 April 20 to May 10, and it was between these two dates in both years that the 

 majority of nests were discovered. 



The average set seems to be three eggs, but four is also a common number. 

 Several sets of two eggs were taken in advanced stages of incubation, and also two 

 sets of five, but these are rare. 



The eggs are a pale greenish blue several shades lighter than eggs of Astrag-a- 

 liniis, and are marked with chocolate spots and irregular blotches, with a number 

 of pale lavender blotches which appear to be beneath the surface of the shell. Eggs 

 vary from very nearly unmarked, to well marked about the larger end and spar- 

 ingly over the whole surface. The average size of all eggs at hand is .63 by .48 inches. 



Sa?i Francisco, CaliJor7iia. 



