Landers el ai • SIZE DIMORPHISM IN WESTLAND PETRELS 
723 
TABLE 2. Pearson product-moment correlations among morphometric characteristics of female and male Westland 
Petrels (n = 37). 
Head length 
Minimum bill depth 
Bill length 
Tarsus length 
Middle toe length 
Wing length 
Head length 
Minimum bill depth 
0.35* 
Bill length 
0.14 
0.58* 
Tarsus length 
0.24 
0.11 
0.08 
Middle toe length 
0.25 
0.35* 
0.32 
0.46* 
Wing length 
0.36* 
0.17 
0.32 
0.46* 
0.51* 
Body mass 
0.42* 
0.31 
0.21 
0.28 
0.47* 
0.34* 
* P < 0.05. 
seven females and 28 of 30 males with an 
accuracy of prediction of 95%. The jackknife 
validation method produced the same classifica¬ 
tion result. The resulting discriminant function 
(DF) from the standard DFA is: DF = (0.37*HL) 
+ (0.89*MBD) - (0.06*BL) + (0.04*TL) - 
(0.01 *MTL) - (0.04*WL) - (0.01 *BM) - 43.03. 
The corresponding canonical classification 
function for males is DF = (20.29*HL) + 
(I5.70*MBD) + (6.14*BL) + (6.23*TL) + 
(5.40*MTL) + (20.61 *WL) - (0.18*BM) - 
1,982.20, and for females is DF = (19.22*HL) 
+ (13.13*MBD) + (6.32*BL) + (6.10*TL) + 
(5.4I*MTL) + (20.51*WL) - (0.18*BM) - 
1,862.00. 
DISCUSSION 
We recorded a slight male bias, based on 
molecular markers, in our sampling effort. This 
may be due to time of year (establishment and 
-3.5 -3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2 5 3 0 
Discriminant score 
FIG. 2. Classification of morphometric characteristics of male (gray bars) and female (black bars) Westland Per, h. 
d,SCr "““' *“■" <DFA > ^ »» breeding sea™ appiying discri^an, 0F, 
