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Nov., 1919 
FROM FIELD AND STUDY 
Association of Migrating Waders.—Mention of collecting a male and female of the 
Baird Sandpiper by L. E. Wyman in the July-August Conpor (p. 172), calls to mind ob- 
servations made by myself on migrating shore birds on the Atlantic coast during recent 
seasons. It was early noticed that the first birds to come south in the fall as well as the 
late ones travelling north in the spring, were very often seen two together. At times 
they appeared to be male and female, which is quite possible to determine in some spe- 
cies without taking specimens, the female being so much larger and longer billed. At 
other times they looked just alike. At first I took it for granted that these birds were 
mated pairs, but more recently I have come to have little confidence in that hypothesis. 
Too often have a couple of boon companions, separated from the crowd and evidently 
counting a good deal on one another’s society, been of different species, a Least and a 
Semipalmated Sandpiper or even a Ringneck Plover and one of the smaller species. It 
also appears that three birds travel in company as often as two, perhaps more often in 
the late summer, and my belief is that these associations are, in general, purely platonic. 
We know that there are times when we prefer to travel with one or two chosen com- 
panions rather than with a crowd, and the more I see of them the more comparable to 
our own the social instincts of the shore birds appear. This point of view does not rest 
on sufficiently definite data to be called a scientific observaton, but nevertheless I would 
like to present it for consideration—JoHN T. NIcHOLS, New York City, August 15, 1919. 
White-throated Swift in Contra Costa County.—On the left hand side of Pine Can- 
yon, Contra Costa County, about a mile above Ford’s Ranch, which is at the entrance to 
the canyon, are some large rocks containing various ledges and cracks. While passing 
through the canyon on July 5, 1919, I noticed several White-throated Swifts (Aeronautes 
melanoleucus) sailing about these rocks. I therefore climbed up to see if their nesting 
site was accessible. 
I managed, with stocking feet and small finger holds, to climb up the face of the 
rock to an almost inaccessible place, where two big rocks come together. In this crack 
was an unoccupied nest situated on a small wedged-in stone. Four feet above this nest 
was another which was occupied, as the old bird was flushed. While trying to decide 
which was the best way to reach this nest, the old bird came back at full speed and 
swooped up to it almost hitting me in the face. This proves that they do not always 
slow down in their speed when entering the nest. 
After some delicate climbing and balancing, the nest was reached and found to 
be empty. But right above it, in a small crack, were two young birds almost ready to 
fly. After trying to poke them down with a small stick I had to give it up as the little 
birds squeezed farther in the crack. There were more nests elsewhere in the rocks, as 
about thirty birds were observed sailing back and forth over the canyon.—LUTHER 
LITTLE, California Academy of Sciences, San Francisco, California, August 26, 1919. 
Luck.—If the writer had not been possessed of a certain amount of this “article” 
these notes would not have been written. Briefly told the facts are these. 
A certain pair of Nuttall Woodpeckers (Dryobates nuttalli) chose a partly decayed 
fence post for a building site. The same location had been selected by a family of bum- 
ble-bees. The woodpeckers started near the top of the post and drilled their excavation 
downward, while the bees started some two feet below and burrowed upward. The two 
openings met and the woodpecker remained in possession. 
It so happened that Mrs. Woodpecker laid a runt egg which promptly slipped into 
the trap nest provided by the bumble-bee, and at the time the writer examined the post 
the small end of the woodpecker egg was protruding from the opening of the bumble-bee 
excavation, fully a foot below the bottom of the woodpecker’s nest. In the woodpecker’s 
dug-out were four normal eggs. 
If the runt had been slightly smaller, if the bumble-bee hole had been slightly 
larger, or if the egg had lodged or broken in its winding journey through the tunnel of 
