Borwein 1952. 38. Journal Sept. 4 6 mi. E. Truchas, 10,000 ft., Rio Arriba Co., New Mexico. Temp. at 5:45 AM (MST) in shade (at sunrise) 41.0° F. Picked up 40 Museum specimens set along stream, under alder and aspen, 4 in open field under fir & aspen, 4 along marshy meadow along felled aspen & living fir. One Sorex sp. taken 2 ft. from stream at base of aspen. One Microtus sp. taken at base of alder in wet meadow. One chipmunk snapped at base of roll fence. From 6:50 AM to 9:30 AM. hiked along streamside & along crest of surrounding slopes, in a circumference around camp of about 2 miles. Observed the following: Steller Jay, Ruby-crowned Kinglet (107), Mt. Chickadees, Blue Warbler, Paleolated Warbler, Townsend Warbler, House Wren, Red-shafted Flicker, Raven, Clark's Nutcracker, 1 White-breasted Nuthatch, many gopher diggers, Chipmunk (numerous) Golden-mantled Ground Squirrel, Canada Jay. Warblers were most abundant in aspen groves & also noted in older thickets. Could not detect any pronounced N→S or down Mt. slope (E→W) migration. Chickadees were particularly abundant in one locality of Douglas Fir, where 3 were seen 'scolding' at one time. The following temperatures were obtained: Species Temp: Time Conditions House Wren 39.4°C 7:50 AM dead 15 sec. Townsend Warbler 40.5°C 8:25 AM dead 10 sec. Paleolated Warbler 41.2°C 8:30 AM dead 3 sec. Saw one Chipmunk 15 ft. high in a Douglas Fir tree.