Marshall, 1945 31 Palau Otus podargris so that entire tapering off & last pt. of climax is given same (but not in unison) as ?. Lower in pitch and mellow tone, breathy at the last. ? ?: --..--... <---(longer)---> .--.--.-..-..-.--. ?: I haven't proven by collecting I have call a ? which was giving full sequence alone - that it was a ? - but was out of terr. perhaps unattached ?. ::: I conclude ?'s either unattached or separated by 100 yds from ? will give the ? sequence but at a lower pitch & more mellow. The flight to new perch during taper-off is generally 25-50 yds. Often both birds fly together to a new tree. 15 min. later they will call from a perch near where the last sounds were given in flight. I I have observed a close parallel to this performance in Otus asio at Altadena which culminates in ? & ? finishing a duet at the same tree (starting out from a different tree, but as I recall, it is the ? which joins the ? - who stays the whole time in one perch. 1st part is the "booming ball" call, 2nd pt (duet) is the double trill. Eyeslime white.