Figure 9From: Comparative tests of ectoparasite species richness in seabirdsRegression between global population size and overall lice species richness. Lice species richness was controlled for sampling effort using residuals from the Google Scholar citation counts. A, Regression for non-phylogenetic analysis of species values (slope = 0.41, F = 16.82, d.f. = 301, P < 0.0001). Pelecaniiformes are represented by blue squares, Charadriiformes by red triangles and Procellariiformes by green crosses. B, Regression using independent contrasts (slope = 0.43, F = 33.4, d.f.= 196, P < 0.0001).Back to article page