Remsen, J.V. 1975 Common Yellowthroat Geothlypis trichas Mar.14 Coyote Hills Reg. Park, Alameda Co., Calif.: I sang in air - only a short flight, rising maybe 3' above cattails and staying aloft only a second or so - but definitely an aerial song Oct.13 Monterey area, Monterey Co., Calif.: a very strangely-plumaged imm.♂ was seen around the Pacific Grove sewage plant. It had been identified the previous day as a Kentucky Warbler - and again this morning as one by me - sharply outlined dark patch behind and below eye (not fuzzy as in most imm. ♂), no whitish border above mask, just a tinge of black in front of eye, partial white eye ring (especially on left side), and intensely yellow underparts - no visible pale belly or buffy on flanks. At MV2, even adult males showed distinctly white bellies - on only one out of hundreds of specimens could it be thought to have an all yellow belly. Imm. birds always showed obviously pale bellies.