98 THE CONDOR Vol. XXIII 
flying to the ground and returning to feed the young. We were unable to find out what 
their prey was. This performance was repeated for several evenings; then they were 
not seen again, although their soft call-notes were heard frequently throughout the sulu- 
mer. These owls are a welcome addition to our fauna and I hope they will continue to 
favor us with their presence.—Joun McB. Rozvertson, Buena Park, California, February 
16, 1921. 
American Crossbill Eating Elm Aphis.—Opportunity for close observation on the 
feeding habits of the American Crossbill (Loxvia curvirostra minor) were afforded the 
writer on the University of Washington campus at Seattle on June 17, 1920. In the mid- 
morning I heard the chup, chup, chup of some Crossbills, and shortly a dozen or more of 
the birds alighted on the lower branches of some cork elms, within ten feet or less of 
the ground. The birds were not disturbed by my close approach and it was possible to 
get within three to five feet of them. Red plumaged males, other individuals oi greenish 
yellow coloration, and one or two with streaking indicative of juveniles were noted in 
the flock which was scattered through half a dozen adjacent trees, 
The birds seemed to prefer to feed while hanging inverted; in a majority of cases 
this was the position taken even when suitable forage could have been obtained from an 
upright posture. When climbing from one branch to another a few of the Crossbills 
were seen to use their bills, after the manner of parrots, but only in making a slight 
change of position while a bird was hanging upside down, or when regaining an upright 
position. 
No buds were to be seen on the trees and for a short time I was puzzled to know 
what the birds were feeding upon. They were attacking certain of the leaves which 
were curled up on one edge, cutting these rolls open and getting something from within. 
Gathering a few similar leaves from a tree and picking up some that had failen after 
being cut open by the birds, it became evident that a woolly aphis, which had caused 
the curling of the leaf margin was the item of food being sought by the Crossbills. The 
attack of this insect causes the blade of the leaf to curl over, forming a cylindrical roll 
within which the aphids can feed and multiply unmolested by most of their enemies. 
Further watching of the Crossbills showed that the birds had learned the haunt 
of these particular aphids and also a method for obtaining them. The roll-like cases 
were cut open lengthwise, but in rather irregular fashion, as well as could be expected 
of a species with such an unhandy pair of ‘‘scissors’; then the tongue would be inserted 
and the aphids withdrawn. The process was not as efficient as it would have been with 
a typical insect-eating species possessed of a slender bill, and many of the insects adhered 
to the outside of the birds’ mandibles. From time to time a bird would cease feeding 
and wipe the adhering bugs and “juice” from its bill. 
That this method is not an entirely novel one with the birds observed by me is 
indicated by the fact that Visher (Awk, xxvi, 1909, p. 150) records briefly similar behavior 
of Crossbills in taking aphid galls on petioles of cottonwood in South Dakota. Still 
other observers have reported the taking of insect food by Crossbills, ‘‘Worms” [prob- 
ably borers] have been eaten in South Carolina (Wayne, Awk, v, 1888, p. 208), and hairy 
caterpillars, the larvae of Clisiocampa disstria at Brandon, Vermont (M. M. Miller, Awk, 
Xvi, 1899, p. 362), while in California lepidopterous pupae have been found in the crop 
of Lovia curvirostra bendirei near Lake Tahoe (L. H. Miller, Connor, xxi, 1920, p. 78.—- 
Tracy I. Storer, Museum of Vertebrate Zoology, Berkeley, California, March 15, 1921. 
Further Notes on the Harlequin Duck’s Food Habits.—The following may be of 
interest, with reference to Dr. Bryant’s note, “The Harlequin Duck in the Yosemite Val- 
ley” (CoNnporR, xx1II, p. 35), in which he says, that “apparently the Harlequin does not 
procure all of its food by diving . . .”. On May 14, 1914, I was making my way up 
St. Leon Creek, British Columbia, when I saw a pair of Harlequin Ducks (Histrionicus 
histrionicus) sitting out on a sand-bar, busily engaged in preening. A thick under- 
growth enabled me to get very close to them. I had been watching them for several 
minutes, when another male flew down the creek and settled close to the pair. The first 
male resented this intrusion, and drove the new arrival into the water, and he was at 
once carried away by the swift water and lost to sight. The pair soon followed him into 
the creek, and I fully expected to lose sight of them, too; but they immediately com- 
