430 U-S. NATIONAL MUSEUM BULLETIN 237 part i 



adoration than could be contained in so small a body, he described 

 circle after circle around his chosen mate. That the female reflected 

 none of her partner's emotion in no way seemed to dampen his ardor 

 and, after he dropped on to a twig from pure exhaustion to catch his 

 breath, a few moments later he rose again in a repeat performance no 

 less ecstatic than the first. 



"None of the flight song performances I saw ended in copulation. 

 When that took place in my presence, it was an anticlimax to what 

 1 had previously seen. Two birds came to the salt lick and one of 

 them perched in a bush. That very instant the male alighted directly 

 upon the first bird by the pouncing technique without any sort of 

 prehminaries. Copulation took place with both birds trembling 

 violently. When it was over, the female begged and the male, 

 with nothing in the bill, performed a token feeding. The female 

 shook herself and both birds hopped down on the ground where the 

 male strutted a little with raised head feathers." 



Formation of the pair bond involves symbolic feeding, sexual flight, 

 and song, and it occurs while the birds are in social groups. Single 

 brood monogamy is certain, but how much longer the pair bond lasts 

 is not known. 



Nesting. — At times Siskins nest as isolated pairs. More usuaUy, 

 nesting is somewhat a colonial affair, with the nests rods apart. 

 Adults join in social flocks away from the nests. 



Typically, the nest is at middle height in a conifer, well out, and 

 concealed on a densely foliaged horizontal limb. The most frequent 

 departure from this pattern is for the nest to be located lower down, 

 but when this happens it is still usually above 8 feet from the ground. 

 Commonest choices for nesting are hemlock, pines, spruces, firs, 

 cedars, redwood, cypress, and wild lilac. Introduced conifers, also 

 transplantings of native trees, are occupied in addition to natural 

 stands. Deciduous trees are used for nesting occasionally. For 

 example, the siskin has nested in box elder in New Mexico (F. M. 

 Bailey, 1928) and North Dakota (R. Reid, 1929), in maples and oaks 

 in Oregon (C. Keller, 1891), in maple in Washington (R. T. Congdon, 

 MS.), in the very top of a 50-foot eucalyptus in California (Carriger 

 and Pemberton, 1907), among cottonwoods in Montana (A. A. 

 Saunders, 1912, 1921), and two nests in lilacs in Colorado (F. M. Dille, 

 1900). The highest nests are at about 45 to 50 feet. In manuscript 

 notes, S. F. Rathbun recorded a nest in Washington only 414 feet 

 above ground in a stunted cedar. The lowest record at hand is of a 

 nest in Iowa, recorded by Dales and Bennett (1929) as only 3 feet up 

 in a 4)^-foot cedar on a lawn. During resting periods the birds go to 

 tree tops. 



