Table 2.

Results from analysis of molecular variance (AMOVA) for different grouping methods. Study areas were divided by: (i) the four clusters identified in program Structure; (ii) subspecies (lumping the two northern spotted owl clusters into a single group); or (iii) north versus south of the Columbia River (only including individuals from the range of northern spotted owls).

Grouping	No. of groups	Variance components	Variation (%)	P-value
Structure clusters	4	Among groups	3.83	<0.001
		Among study areas	1.95	<0.001
		Within study areas	94.22	<0.001
Subspecies	3	Among groups	8.64	<0.001
		Among study areas	2.09	<0.001
		Within study areas	89.27	<0.001
N versus S of Columbia R.	2	Among groups	0.58	0.016
		Among study areas	2.19	<0.001
		Within study areas	97.23	<0.001