Table 3.

Values of the principal component loadings for the studied elements in the eggshells of black-headed gulls

Elements	PC 1	PC 2	PC 3
Al	0.80	0.32	0.18
As	0.47	−0.31	0.30
Ca	0.49	−0.20	−0.31
Cd	0.47	0.14	0.43
Cr	0.00	0.35	−0.48
Cu	0.03	−0.20	0.53
Fe	0.89	0.26	0.11
Mg	−0.37	−0.10	0.18
Mn	0.73	0.23	−0.15
Mo	0.21	−0.36	−0.02
Ni	−0.08	0.78	0.16
Pb	0.05	−0.08	0.51
Sc	−0.17	0.83	−0.03
Se	−0.20	0.12	0.38
Sr	−0.17	−0.07	0.29
V	0.68	−0.12	0.17
Zn	−0.53	0.26	0.52
Eigenvalues	3.7	2.1	1.8
Total variance explained (%)	21.6	12.2	10.5

All significant correlations (P > 0.05) are highlighted in bold and highly correlated values (r > 0.70) are in italics