Table 1.

Loadings and correlation of sperm traits with principal components of sperm velocity and trajectory shape in five hamster species. Values presented are Pearson’s correlation coefficients. Significant correlation coefficients (p < 0.05) are shown in bold. PC1: principal component 1. PC2: principal component 2. Variable values were log₁₀ or arcsine transformed prior to analysis.

Variables	Factor Loadings		Factor Correlation
	PC1	PC2	PC1	PC2
Sperm velocity principal components:
Curvilinear velocity	0.5667	−0.7023	0.9405	−0.3345
Straight-line velocity	0.5658	0.7118	0.9390	0.3390
Average path velocity	0.5989	−0.0079	0.9938	−0.0038
Sperm trajectory shape principal components
Linearity	0.5800	0.0041	0.9914	0.0047
Straightness	0.5008	0.1996	0.8560	0.2302
Wobble coefficient	0.5261	0.0217	0.8992	0.0251
Amplitude of lateral head displacement	−0.3498	0.5869	−0.5980	0.6767
Beat-cross frequency	0.1167	0.7844	0.1995	0.9045