1926] Swarth: Birds and Mammals from the Atlin Region 63

seen continually in some numbers along the lake shore, and the species
was probably nesting at various points. We did not discover the
colony alluded to above until all young birds had left the nests. Due
to the ravages of the herring gull, as seemed evident, eggs and young
in this colony were destroyed until just one young bird remained. This
lone survivor, with wing quills partly grown but not yet able to fly,
was several times seen, swimming on the lake, dodging attacks from a
herring gull, which persisted until the entire adult population ue
short-billed and Bonaparte gulls came to the rescue.

A short-billed gull’s nest was discovered July 15 on the ‘‘middle
island’’ opposite the town of Atlin. It was placed in the top of a
small balsam fir (with which trees these islands are thickly covered),
about fifteen feet from the ground, and not at all easy to see in the
flattened tree-top where it was placed. The young had been gone for
some days at least, and buried in the bottom of the nest, entirely
covered and hidden, was an addled egg (no. 1978). One or two other
nests were seen in similar situations.

Two specimens of short-billed gull were preserved, an adult male
(no. 44628) taken June 15, and a young female (no. 44629) molting
from down to first winter plumage, taken July 14.

Larus philadelphia (Ord). Bonaparte Gull

Seen at Carcross, May 22. Two days later a pair of these birds
had apparently preémpted one end of a slough at the edge of the
town, and they dived at our heads with loud outcries whenever we
approached.

At Atlin, this species, like the short-billed gull, was nesting on the
islands opposite the town, and, as with the larger species, the young
had left the nests before we discovered this breeding ground. There
were apparently ten or twelve pairs of Bonaparte gulls domiciled upon
the islands, and, due again to the raiding herring gulls, from all these
broods but three young birds reached an age when they could fly.

Several nests were found on the islands, which, without question,
must have belonged to this species. They were frail affairs, not much
larger than waxwings’ nests, placed on widespreading side branches
of balsam firs, near the tops of the trees, some fifteen or twenty feet
from the ground. Just as is seen in the descriptions of Bonaparte
gulls’ nests given by the several authors that are quoted in Bent’s
(1921, p. 176) “‘Life Histories,’’ they were suggestive of pigeons’
nests more than anything else.