Table 1.

Note duration, centre frequency and fundamental frequency of outside and inside calls recorded from different males. N1, N2, N3, N4 and N5 represent the first, second, third, fourth and fifth note of the calls, respectively. Mean ± s.d., n = 20 males for outside call and n = 30 males for inside call.

	note duration (ms)		centre frequency (Hz)		fundamental frequency (Hz)
	outside	inside	outside	inside	outside	inside
N1	170.0 ± 34.7	215.6 ± 29.9**	1467 ± 344	826 ± 192**	455 ± 53	427 ± 42*
N2	138.6 ± 26.1	167.6 ± 19.8**	1622 ± 347	804 ± 243**	553 ± 60	509 ± 47**
N3	129.0 ± 25.6	149.8 ± 16.8**	1563 ± 370	753 ± 175**	593 ± 87	538 ± 48**
N4	124.0 ± 21.9	139.2 ± 16.8*	1574 ± 312	749 ± 170**	594 ± 55	538 ± 44**
N5	121.2 ± 22.2	133.0 ± 14.2	1587 ± 312	785 ± 194**	587 ± 43	561 ± 47

*p < 0.05, **p < 0.01.