Table 4.

Results of post-hoc t-tests examining variation in acoustic parameters between calls recorded in 1994 and 2005 at six sites in the North dialect

	d.f. for all tests	PCA 1	PCA 2	PCA 3	PCA 4	PCA 5
Hacienda Inocentes	9	1.5	0.2	−0.1	−0.6	0.4
Playa Junquillal	8	−2.9 *	1.2	0.1	2.2	1.5
Murcielago	8	−3.3 *	3.7 *	−3.0 *	2.0	2.0
Pelon Altura	11	1.0	−1.6 *	−4.0 *	−0.9	0.7
Horizontes	8	−1.4	5.4 *	−6.3 *	−1.0	2.5 *
Playa Cabuyal	7	0.8	1.3	−2.2	1.9	2.8 *
All six sites combined	61	−2.0 *	3.1 *	−4.8 *	0.8	3.2 *

^*t-values with P < 0.05