Integrative taxonomy of the Plain-backed Thrush (Zoothera mollissima) complex (Aves, Turdidae) reveals cryptic species, including a new species

Table 2 Summary statistics for PCAs presented in Figs. 2 and 3 for the Z. mollissima–Z. dixoni complex

Component loadings	Reduced external measurement set A, both sexes		Reduced external measurement set B, both sexes		Full external measurement set, males only
Component loadings	PC1	PC 2	PC1	PC 2	PC 1	PC 2
External measurements
Culmen l from skull					−0.49	0.04
Bill w from distal nares	−0.03	0.10			−0.12	−0.06
Bill d from distal nares					−0.17	0.05
Culmen ridge w					0.03	0.06
Bill hook l					−0.09	0.10
Rictal bristle maximum l					−0.29	−0.09
Wing l (flat and stretched)	*5.45*	0.28	3.70	*4.00*	2.64	*4.09*
Wingtip l					0.55	1.82
Tail l			*7.81*	−1.89	*8.75*	1.52
White on outer rectrix, maximum					*3.30*	− *5.55*
White on outer rectrix, minimum					*2.42*	−2.99
Tarsus l	0.87	−1.74	1.33	0.01	1.28	0.40
Hind claw l					−0.11	0.23
Eigenvalues	30.45	3.13	76.40	19.38	102.56	62.32
% total variance explained	90.22	9.28	77.83	19.74	51.78	31.45
Plumage scoring
Lower mandible base color	0.99	−0.01
Crown color	1.36	−0.77
Supraloral	1.24	0.28
Lores	*1.81*	0.09
Auriculars % pale	0.39	0.08
Submoustachial prominence	1.16	−0.12
Malar strength	1.41	0.03
Throat color	*1.82*	0.01
Throat markings	−0.27	0.81
Central breast marking shape	0.7	−0.88
Central breast marking density	0.77	0.56
Flank marking shape	0.24	*2.44*
Flank marking density	0.65	0.33
Undertail–tail tip contrast	1.60	−0.86
Claws darkness	1.16	−1.61
Folded wing pattern strength	− *1.05*	−0.47
Secondary covert edge width	*1.49*	*1.86*
Secondary covert edge color	0.74	0.42
Upperparts color	1.74	−0.41
Eigenvalues	26.37	15.89
% of total variance explained	36.29	21.87

Loadings deemed especially important in bold italic, those of intermediate importance in italics only
l length, w width, d depth

ISSN: 2053-7166