3.3 Correlations between prey items and relative specialization
Correlation analysis between diet proportions of prey orders and\(\text{PS}_{i}\) revealed that eight orders out of twelve showed
significant correlations (alpha = 0.0038, Bonferroni correction, Table
3). Adult Salmoniformes, a largely pelagic group, were correlated with a
generalist diet (rho = 0.27, p < 0.001) while juvenile
Salmoniformes showed no significant correlation. Clupeiformes, another
largely pelagic group, correlated with a generalist diet as well (rho =
0.24, p < 0.001). Conversely, Pleuronectiformes, a demersal
and benthic group, correlated with a specialist diet (rho = -0.38, p
< 0.001). Further, Gadiformes, which has both pelagic
and demersal representatives, showed no correlation (rho = -0.04, p =
0.38).
Correlations performed with just data from female scat showed similar
patterns. All orders of prey showed the same relationship with\(\text{PS}_{i}\), or were no longer significant, such as Salmoniformes
(Table 4). The only new order to show significance was
Batrachoidiformes. Correlations performed with only male scat once again
showed similar patterns. New orders to show significance were
Chimaeriformes (with a specialist diet) and adult Salmoniformes (with a
generalist diet) (Table 5).
The correlation between proportion of benthic species in each scat and\(\text{PS}_{i}\) suggested a positive relationship between the amount
of benthic species consumed and the level of relative specialization
(rho = -0.384, p > 0.001). A similar relationship was
observed when the female and male data sets were examined separately
(rho = -0.407, p > 0.001; rho = -0.35, p >
0.001 respectively).