Characteristics of territorial songs of Indonesian and Malaysian Otus with single whistled songs.

Data presented are mean ± standard deviation (minimum and maximum values). Significance levels of comparisons with O. jolandae are indicated with asterisks (* PPPPaF1, frequency at start (Hz); F2, frequency at end (Hz); F3, frequency at 25% of total song duration (Hz); F4, frequency at midpoint (Hz); F5, frequency at 75% of total song duration (Hz); F6, frequency at maximum amplitude (Hz); F7, maximum frequency (Hz); F8, minimum frequency (Hz); DT1, total song duration (s); DT2, time to maximum amplitude (s); DT3, time to maximum frequency (s); DF1, frequency drop from start to end (Hz); DF2, frequency range (Hz); DFT1, slope from 25% to 75% of total song duration (Hz/s); DFT2, slope from midpoint to end (Hz/s); b For F6 and DT2, sample size is 12; c For F6 and DT2, sample size is 6.