Transcribing the field notes of the Museum of Vertebrate Zoology

Collector: Grinnell - 1925 Location: Lassen Section (Mineral) Date: June 14-15, 1925 Page Number: 2465

nearby and, to my astonishment, perched at the top of an outermost twig for fully 5 minutes without changing its location, every now and then giving its song. The bird would change position only to the extent of swinging the axis of its body about 45° now and then - "looking" in another direction. I never before saw a Kinglet keep one perch so long (my estimate 15 minutes was surely conservative). The bird was a male, probably in position to overlook its nesting domain, for within 100 feet was the focus of the alarm "dinge" previously mentioned. June 15 9 a.m. - Just found a Western Warbling Vireo's nest, by tracing the volubly singing bird to it. He sits there, eyes me intently from time to time, but continues to sing snatchily. The nest is about 18 feet up in a black cottonwood growing at the edge of a division of Battle Creek. It is about 6 feet out from the trunk, on the northeast side of it, in a forking twig near the end of a drooping branch, but with a canopy of the big green leaves of a longer upper branch immediately above it. Shade seems to be assured in this case. The birds' tail projects well beyond the nest rim, and is depressed with the rhythm of the singing. The birds' mandibles open very widely with the fullest-toned utterances. This nest not climbed to. Nest of Sierra Junco: on ground at northeast.

Collector: Grinnell - 1925 Location: Lassen Section (Mineral) Date: June 15, 1925 Page Number: 2466

base of small cedar (only 32 in. tall) in grassy place (dandelions and buttercups all about also) beneath scattering lodgepole pines (some dead). The four eggs fresh but cold. Old birds (perhaps of this nests) in near vicinity solicitously tending nearly grown young (flying about ably). Nest sits about 20 steps from edge of stream and willow thickets. Diameter of nest, in situ, 55 mm. Taken. This Junco's (1/4) nest was found yesterday by Mrs. G incidentally to hunting grasshoppers for fishing purposes! While the nest rim was about 1/2 inch above general level of sod surface, when lifted out, it was found to have occupied a deeply hemispherical cavity. 90 mm. across and 55 mm. deep. The walls of the nest are thus rather thin this compactly woven. Western Wood Pewee nest: directly above the Junco's nest! About 14 feet above ground and 7 feet out from trunk (of lodgepole pine) on dead, nearly horizontal branch, at forks of same so that only rim of nest between the forks shows from below; diameter of limb at forking about 4 inches. Of seemingly usual construction. Solicitous and persistent calling of one of the birds nearly prompted scrutiny of appropriate sites round about. Not disturbed. Just saw a male Sharp-shinned Hawk fly over the tree-tops in straight-away course toward where I saw the female day-before-yesterday. No doubt there is a nest of young there somewhere.

Collector: Grinnell - 1925 Location: Lassen Section (Mineral) Date: June 15, 1925 Page Number: 2467

Heard a Black-headed Grosbeak in full song in willows, with twinkling aspens and lodgepole pines on either side! 11:30 a.m. - A female Audubon Warbler gave us a long chase. No male at all put in an appearance. The female showed wild solicitude, suddenly appearing as we went under some lodgepole pines at the edge of a meadow. I supposed a nest near, so for fully 20 minutes we kept her in view, she going to the tree tops, at times almost out of sight, then back down near us. Then I began to circle about; and when I got near a certain thicket of very small pines and willows, the bird came within ten feet of me, and went thru with an elaborate display to distract my attention. She spread her tail fanwise, showing the white spots to greatest effect, and quivered her partly spread wings, topping over backwards at the same time, as if unable to hold to her perch. For an instant I thought her foot was caught in the forking twigs! Of course there must have been partly fledged young in the low vegetation somewhere, tho we did not hunt for them. Certainly there was no nest close by. Heard a Meadowlark in full song out on the big meadow at 5:45 a.m. Considerable frost at that hour, even up 3 feet from the ground on the leaves of ceanothus. On way to store saw a pair each of Western Bluebirds and Tree Swallows.

Collector: Grinnell - 1925 Location: Mineral Date: June 26 Page Number: 2500

nest found ten days ago, barely began; 3 eggs in nest day before yesterday.

6269 Wright Flycatcher [female symbol] with set 4/4 11.0 g. Had evidently had an accident by which a lot of feathers on back were lost, there being now in process of replacement. Possibly, delayed nesting due to this accident.

June 27 4 p.m. - Cassin Vireo's nest: rim 1750 mm. above ground; nest near end of drooping cedar branch, 7 feet out ^^{(on south side)} from trunk of tree, which is 15 inches in diameter 3 feet from ground. Site about 10 yards from edge of willow bog on one side and less distance from heavy stand of firs, on the other side; lodgepole pines bordering bog close by. This nest was found partly built on the 15th, empty but seemingly completed on the 20th, now with 4 fresh or nearly fresh eggs ^^{(two of them)} and female incubating. Taken, set 2/4. Male bird sang awhile, then went away. After I had waited 20 minute, the [female symbol] came quietly, and I "collected" her.

5 p.m. - Traill Flycatcher nest and set 1/4, taken. Nest, not quite completed, found on 20th, now four eggs, nearly or quite fresh; birds close about me. Nest in dense willow jungle. Rim only 1040 mm. above running water of creek, here entirely overgrown with matted willows. Nest on slanting stems, overtopped by fully 5 feet of lush willow growth.