Mar., 1916 
81 
FROM FIELD AND STUDY 
A Note on the Food of the Western Robin. — In front of the Biological Station build- 
ing at Flathead Lake, Montana, a small spring seeps into the lake, making a damp spot 
in the sand of the lake shore. Here, in the month of July swarms of butterflies congre- 
gate to drink. The butterflies are principally of two species, Papilio rutulus, a large 
yellow and black one, and Papilio eurymedon, an equally large one in cream color and 
black. These butterflies became so absorbed in their drinking that they could be easily 
approached and sometimes picked up in the fingers. One day, I was much amused to 
notice that a Robin ( Planesticus migratorius propinquus ) took advantage of this and 
found them a ready source of food supply. The bird would approach and watch until 
one fluttered its wings, and then would seize it and swallow it wings and all. I watched 
it for some time, and noticed that the yellow butterflies were the only ones eaten, 
although the others outnumbered them almost three to one. Whether the brighter color 
attracted the bird to these, or the others were distasteful, cannot be said with certainty, 
but I believe the former to be the case. A chipmunk, which also fed on these butterflies, 
caught and ate both species, carrying them to the shelter of a log, where it discarded 
the wings, leaving them in a large heap. — Aretas A. Saunders, New Haven, Connecticut. 
Slight Extension of Range of San Diego Titmouse. — On December 19, 1915, at least 
two San Diego Titmice (Baeolophus inornatus murinus) were noted with a flock of 
Bush-tits (presumably Psaltriparus minimus minimus) among the junipers on the high 
mesa at the south edge of the Mohave Desert, the exact spot being approximately five 
miles south and four miles west of Hesperia, San Bernardino County, California. The 
mesa at this place is about 3800 feet altitude and less than a mile farther south drops 
off abruptly into Cajon Pass, through which there would be no physical barriers to the 
localities on the other (south) side of the western portion of the San Bernardino Range, 
regularly inhabited by this subspecies. The junipers end a half mile north of this rec- 
ord, where typical Lower Sonoran vegetation immediately replaces it. One of the two 
birds was taken, an adult female (no. 4587 coll. J. E. Law) and has been pronounced 
“ murinus ” by J. Grinnell after comparison with the series of both “ inornatus ” and 
“ murinus ” in the California Museum of Vertebrate Zoology. 
The weather was at this time, and had been recently, entirely normal, clear warm 
days and crisp frosty nights, and the birds seemed to be very much at home, as were the 
bush-tits. Flocks of the latter and- at least one “ murinus ” were observed on the 20th. 
Unfortunately no bush-tits were collected, for this is near the recorded desert limit of 
its range as well. — J. Eugene Law, Hollywood, California. 
Nature of the Occurrence of the Rose-breasted Grosbeak in Humboldt County, Cali- 
fornia. — It would appear from Pacific Coast Avifauna no. 11 (p. 135) that the Rose- 
breasted Grosbeak ( Zamelodia ludoviciana) continues to be known from California upon 
but very scanty basis. Since the undersigned was concerned in the first one of the three 
known instances of occurrence, it may be of interest to present additional details. 
On July 1, 1897, our party found this Grosbeak so abundant in the orchard at Myer’s, 
Humboldt County, California, as to be a pest. The people on the ranch made a business 
of shooting the birds to keep them from eating all the fruit. Males and females were 
present and were seen by us, and, as elsewhere recorded, specimens were saved. Can it 
be doubted that they were breeding that summer and that a considerable colony was 
present in that region? While it may be true that the species is a “sporadic visitant’’ in 
California, it would seem certain that, in the year in question, either a flock of consider- 
able size had gone astray and reached the Myer’s ranch or that we had to deal with a 
colony of several years’ standing.— C. H. Gilbert, Stanford University, California. 
Additional Notes on the Birds of Kootenai County, Idaho. — 
Manila valisineria. Canvas-back Duck. Rare fall visitant. A young male, found 
with its neck broken, floating in Lake Coeur d’Alene near a boat house, March 10, 1915, 
may have struck piling or a building in the dark, causing the accident. Reports that 
Canvas-back Ducks have been taken on the lake for several years past have come to my 
notice, but this is the only specimen I have examined. 
