BIRD RECORDS DURING THE PAST WINTER 253 
rose ( Oenothera biennis ). This plant is very abundant on the 
hills and prairies throughout this region, and may form an im- 
portant food of this group of birds, since it stands well above 
the snow and retains its seeds throughout the winter. 
14. Pine Siskin. S'pinus pinus. The Pine Siskin was seen 
only twice through the winter, incidentally confirming its repu- 
tation for irregularity. In 1914 large numbers were continually 
about throughout March, April and the greater part of May. In 
That year a pair even nested in Sioux City. 1 The writer is in- 
clined to think that the bulk of the Siskins pass south of this 
station for the winter, and that we see them here in the early 
spring on their return northward. 
15. Goldfinch. Astragalinus t. tristis. This species was 
quite common through October. Eight were seen on November 
5, and one on December 26. They were seen on six different days 
in January, and may be considered as a tolerably common winter 
bird. 
16. Tree Sparrow. Spizella m. monticola. This is one of our 
most common winter visitors, and if arrived this winter on the 
22d of October. It is often found in good sized flocks, which 
linger until the first of April. After the middle of this month 
only stragglers are seen. On January 21, in company with 
Messrs. A. P. Allen and G. 0. Ludcke, I watched a small flock 
of these birds feeding on the seeds of Squirrel-tail grass ( Hor - 
- deum jubatum L.), which projected above the deep snow. They 
picked the seeds from the heads within reach. Sometimes they 
would hop, or even fly, up to those just beyond reach. But what 
surprised us most was to see several birds deliberately hop onto 
the weak grass stem and bring it down to the snow, where the 
seeds could then be easily got at. At other times it seemed 
as if the birds simply flew against the grass heads, thus shaking 
out the seeds on to the snow, where they were readily picked up. 
I have not seen any previous mention of this interesting be- 
havior, and have since regretted that I did not give more time 
to the observations. 
Even by field observation there is an apparent wide range in 
the plumage color of this species; many are noticeably paler, 
and I have suspected that these may be the Western Tree Spar- 
4S!ee Wilson Bulletin. XXVI, Sept., 1914, pp. 140-146. 
