Marshall, 1938 Otus flammeolus Whitakers - continued.e a lower interval.The hoots are full vowel sounds not whistles,are the vowel oo as in hoot. Staccato effect best imitated by thepronunciat tion of boop,boop,boop,etc. After 20 min.,hooting ceased,to be re- sumed after 1/2 min.near top young Sequoia 35 ft.high,30 yd.away.(This tree again the highest one in clump p.Didn't alight in open- branched black oaks,common thereabouts.Tried to lokate with flashlight but light burned out. Sat down for 1/2 hr.trying to fix - owl kept up continual hooting - returned to original perch. I circled tree clump to determine te-a- which it was in - was definitely the highest fir - 80 ft.high - below top.Owl stopped - resumed with same succession of hoots at same interval but with 2 additional shorter notes,slightly over 1/2 step lower - ahead of each hoot/