PARASITES AND HOST GEOGRAPHIC RANGE AS ILLUSTRATED BY WATERFOWL

Describes a positive relationship between number of helminth parasite species per host and host species geographic range in Holarctic waterfowl. The analysis controls for the effects of differential sampling of host species and for the effects of taxonomic association. None of host body size, population size, population density, or social tendency correlates significantly with the number of parasite species per host corrected for number of hosts examined, and therefore association with these variables is unlikely to confound the relationship between parasites and host geographic range. Analysis illustrates the strong correlation between number of parasite species recorded and sampling effort regardless of the methodology used. Number of host individuals examined is clearly the most useful measure of sampling effort in such data sets. -from Author