Patterns of Distribution of the Tick Ixodes trianguliceps Birula on its Hosts

The survival of a single parasite is dependent on individual adaptations in relation to its specialized situation, while the evolution and survival of the parasite species is the product of an ecological relationship with its hosts at the population level. The patterns of distribution of the parasite on its hosts reflect the biological factors working within the host-parasite interaction (Crofton 1971a, b; Schmid & Robinson 1972), thus providing insight into the nature of the adaptive mechanisms permitting the survival of the parasite species. During a three-year study of the ecological relationship between the tick, Ixodes trianguliceps Birula 1895, and its small mammal hosts (Randolph 1973b) the tick infestation patterns were analysed with respect to the distribution of the ticks on the host population as a whole, and with respect to the variation in tick infestation levels on the different species of hosts and the intraspecific groups of hosts. This latter factor is very important to the understanding of the tick-host relationship, not only because the disparity reflects the importance of each small mammal species as hosts to this parasite, but also because the basis of its cause must lie in the mechanics of how the ticks are picked up and allowed to attach successfully.