578 Field Museum of Natural History — Zoology, Vol. IX. 



lations, usually accompanied on the downward swing by the familiar 

 chee-e-wee . 



Nidification begins in May. The nest is built in large bushes or 

 low trees, and is woven of grass and plant fibre, lined with thistle 

 down. The eggs are from 3 to 6, pale blue or bluish white in color, 

 and measure about .66 x .47 inches. 



Genus SPINUS Koch. 



243. Spinus pinus (Wils.). 



Pine Siskin. 



Distr.: " North America generally, breeding in the British Prov- 

 inces, Rocky Mountains, Sierra Nevada, and high mountains of 

 Arizona, south to Lower California and the mountains of Mexico to 

 Orizaba. Also breeds sparingly in northeastern United States." 

 (A. O. U.) 



Adult: Upper plumage, streaked w4th pale brown and dark brown; 

 under parts, grayish white, streaked with dusky; rump, yellow, 



Pine Siskin. 



Streaked with dusky; at times the whole plumage faintly tinged with 

 yellow and again hardly noticeable; basal portion of quills and tail, 

 yellow. 



Sexes, similar. 



Length, 4.75; wing, 2.77; tail, 2; bill, .35. 



The yellow markings at the base of the wing and tail feathers 

 will distinguish this species. 



This species is common in Illinois and Wisconsin during the mi- 

 grations and a more or less common winter resident, especially in 



