A New Montane Species of Spiny Pocket Mouse (Rodentia: Heteromyidae: Heteromys) from Northwestern Costa Rica Author Anderson, Robert P. Author Timm, Robert M. text American Museum Novitates 2006 2006-03-16 3509 1 1 39 http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1206%2F0003-0082(2006)3509%5B1%3AANMSOS%5D2.0.CO%3B2 journal article 3674 10.1206/0003-0082(2006)3509[1:ANMSOS]2.0.CO;2 2f8c7065-6e4b-46b1-89af-809f51afdcf2 0003-0082 4735318

TABLE 4 Results of Principal Components Analysis for Adult Specimens in Age Class 4 of Heteromys desmarestianus and H. nubicolens from Northwestern Costa Rica a

	Unit eigenvector				Loadings
a Elements of the unit eigenvector and loadings are presented for the first three principal components. Cranial measurements were transformed to their natural logarithms (ln) before components were extracted from the covariance matrix. Eigenvalues (multiplied by 100) and the percentage of the variation among specimens explained are given for each axis.
	PC1	PC2	PC3	PC1	PC2	PC3
ln-Occipitonasal length	20.364	0.096	0.025	20.941	0.201	0.027
ln-Zygomatic breadth	20.301	0.135	20.093	20.794	0.289	20.122
ln-Rostral length	20.466	0.175	0.066	20.906	0.277	0.057
ln-Nasal length	20.469	0.095	0.187	20.902	0.146	0.171
ln-Least interorbital constriction	20.215	20.209	0.652	20.440	20.339	0.654
ln-Squamosal breadth	20.187	0.047	20.046	20.755	0.151	20.095
ln-Maxillary toothrow length	20.268	0.112	20.108	20.669	0.229	20.138
ln-Interparietal width	20.303	20.007	20.638	20.564	20.009	20.583
ln-Interparietal length	20.215	20.919	20.179	20.288	20.934	20.118
ln-Parietal breadth	20.097	20.144	0.270	20.343	20.401	0.464
ln-Skull depth	20.198	0.090	0.015	20.772	0.283	0.027
Eigenvalue (× 100)	1.393	0.885	0.339
% variation explained	42.9	27.2	10.5