Cogswell 1950 Vireo gilvus June 17 near Sugar Bowl Lodge, 7000 ft., 1.2 mi. 55 W Donner Pass, Glacer Co., Calif. - Several heard singing in the scattered young (few old) red firs & lodgepole pines in "Cowgill meadow" which is otherwise grown to clumps of willows with much wet ground & snowbanks with only dead vege- tation or forbs just sprouting. One male was seen singing in a low thicket of, leafless willows near the firs; it interrupted this behavior to approach another vireo, presumably a ♀, which came into the same thicket, mounted it briefly, & then went back to singing. The ♀ fluttered her wings slightly, & soon picked up a thin strip of bark & flew off with it to the firs, the ♂ following closely. From the detached clump of firs I watched them go on into the edge of the main forest at the S border of the meadow. When I reached there the ♂ was singing regularly from a close growing group of 2 Pinus monticola & 1 Tsuga mertensiana. He chased a ♂ Audubon warbler from these trees by repeated short flights directly at the warbler, accompanied by a querulous scold note immediately followed by bill snapping. A Red-breasted Nuthatch which alighted within a few feet of the singing vireo not 5 min. later was unmolested. The ♀ came & went several times, the ♂ following her away, but returning to sing for some several minutes each time before she returned. Finally I located the nest [illegible]. It is hung from a twig crotch near the tip of a