INFERENCE OF PARASITE-INDUCED HOST MORTALITY FROM DISTRIBUTIONS OF PARASITE LOADS

Evidence for parasite-induced host mortality from field data remains d ifficult to obtain. We have developed analytical models to investigate the effects of parasite-induced host mortality on the distribution of macroparasites among individual hosts as a function of host age. Unde r the assumptions of these models, it is shown that a decrease of the mean parasite load or of its dispersion implies that there is parasite -induced host mortality and that infection rate is variable for differ ent hosts in the population. Observed patterns will depend on the natu re of such variation and of the relation between parasite load and hos t mortality.