PINE SISKIN 433 



nesting material March 16 in San Francisco County, Calif. (M. S. 

 Ray, 1916); nest completed March 11 had three eggs on March 18, 

 also nest with two nearly fledged young on April 13, in Lewis County, 

 N.Y. (C. H. Merriam, 1878) ; nest with two eggs and two newly 

 hatched young March 28 or 29, at Tacoma, Wash. (J. H. Bowles, 

 1924); clutch of four on March 29 in Nova Scotia (C. H. Morrell, 

 1899) ; nest with two eggs taken on unstated March day in Ontario 

 (BaUlie and Harrington, 1937); and imstated number of eggs the 

 last of the month in Vermont (Tracy in Mierow, 1946), Fresh eggs 

 in May and early June are common but why many fresh clutches 

 have been found in California in early June is a matter for speculation. 



The set of eggs of the pine siskin varies from three to six ; sets of four 

 and five are most frequent. They are ovate with some tendency 

 toward short-ovate and have very little lustre. The ground color is 

 greenish-white or bluish-white, delicately speckled and spotted with 

 "light cinnamon drab," "cinnamon drab," "warm sepia," or "Verona 

 brown," with a few thin scrawls of black. In general, the markings 

 are concentrated somewhat toward the large end where they often 

 form a loose wreath; rarely an egg is found that is almost immaculate. 



The measurements of 50 eggs average 16.6 by 12.4 millimeters; the 

 eggs showing the four extremes measure 18.0 by 13.1, and I4.S by 11.3 

 miUimeters. 



Eggs are laid on successive days. Weaver and West (1943) say 

 that at Hanover, N.H., both eggs of a two-egg clutch "were laid before 

 nine o'clock in the morning. Incubation began upon the laying of 

 the first egg and the young hatched thirteen days later, one day apart. 

 * * * The danger from freezing of the eggs would appear to be less- 

 ened with incubation beginning upon the laying of the eggs." 



Only the female has an incubation patch and she alone incubates. 

 Weaver and West (1943) write : "During incubation, the female stayed 

 very close to the nest. The longest observed period that the female 

 was off the nest for the entire period of incubation was eight minutes. 

 She was fed by the male during incubation, and this permitted long 

 uninterrupted periods on the nest ; in fact, he began feeding her on the 

 nest the day before the first egg was laid and in one instance was 

 observed to feed her while she was off the nest before the eggs were laid. 



Hatching is described by the same authors (1943) as follows: "Just 

 prior to hatching, the female stood up on the edge of the nest and looked 

 at the eggs a great many times. Hatching occurred early in the morn- 

 ing, before 7:30 a.m., or possibly during the night. There was no sign 

 of the egg sheU in the nest, but later a small piece was found under the 

 tree. 



Young. — In the above-mentioned nest, "feeding of the young began 

 very soon after hatching, possibly within the hour." Weaver and West 



