May 27. Boca Spring, 6000 ft., Nevada Co., Calif. Two kinds (size classes) seemed to be present, than terrorized by flight also and probably referable to Myotis & Eptesicus? Their period of maximum activity lasted about 15 minutes. Heard Horned Owl in distance while I was in bed. May 28 Clear, calm, cold (ice formed on bottoms of some of the aluminum live traps. I ran line & picked up traps. One placed beside a log in the meadow held a Peromyscus - 7 placed around string were empty except for one beneath other willows (contained Permyscus) I left camp about 6:30 AM - bird activity not conspicuous for first hour as I walked N perhaps 500 yards. I followed a small streamcourse into slightly higher elevation where White Fir and juniper were met more commonly and where the frost was not so open. Undergrowth species chiefly squawmat, Parahia, and manzanita. Much pine reproduction in evidence as were burnover & logging (latter perhaps about 1900 as stumps completely rotted). Mountain Bluebird & flew into snag in which Pyggy Nuthatch nesting - it joined her - she inspected one cavity & left, followed by ? - I was out of range. Townsend Solitaire - one of song similar to Robin's Flycatcher - I took one (?, 4/12) singing from snag in denser forest, chiefly Jeffrey pine. Song of 3 parts - chip chee weet zee the second 2-part note sounding somewhat vireo-like, the other two definitely flycatcher. Hairy Woodpecker ? and White-breasted Nuthatch