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Processes influencing the distribution of parasite numbers within host populations with special emphasis on parasite-induced host mortalities

  • R. M. Anderson (a1) and D. M. Gordon (a2)

The paper examines the factors which generate various patterns of dispersion in the distribution of parasites within their host populations. Particular emphasis is placed on the role played by chance elements in the growth and decay of parasite populations and on the influence of different types of demographic processes. It is argued that observed distributions are dynamic, rather than static, entities generated by opposing forces, some acting to create over-dispersion and others acting to generate under-dispersion. Monte Carlo simulation experiments, based on probability models of the growth and decay of host and parasite populations, are used to study the dynamics of parasite dispersion. Attention is specifically focused on the role played by parasite-induced host mortality. It is shown that, for certain types of host–parasite associations, convex curves of mean parasite abundance in relation to age (age-intensity curves), concomitant with a decline in the degree of dispersion in the older age classes of hosts, may be evidence of the induction of host mortality by parasite infection. Empirical evidence is examined in light of this prediction. In general, however, simulation studies highlight the technical difficulties inherent in establishing clear evidence of parasite-induced host mortality from ecological studies of hosts and parasites in their natural habitats.

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Anderson, R. M. (1974). Population dynamics of the cestode Caryophyllaeus laliceps (Pallas, 1781) in the bream (Abramis brama L.). Journal of Animal Ecology 43, 305–21.
Anderson, R. M. (1978). The regulation of host population growth by parasitic species. Parasitology 76, 119–57.
Anderson, R. M. (1979). The influence of parasitic infection on the dynamics of host population growth. In Population Dynamics (ed. Anderson, R. M., Turner, B. D. and Taylor, L. R.), pp. 245281. Oxford: Blackwell Scientific Publishers.
Anderson, R. M. (1981). Epidemiology of infectious disease agents. In Modern Parasitology (ed. Cox, F. E. G.). Oxford: Blackwell Scientific Publishers.
Anderson, R. M., Gordon, D. M., Crawley, M. J. & Hassell, M. P. (1982). Variability in the abundance of animal and plant species. Nature, London 296, 245–8.
Anderson, R. M. & May, R. M. (1978). Regulation and stability of host–parasite population interactions: I. Regulatory processes. Journal of Animal Ecology 47, 219–48.
Anderson, R. M. & May, R. M. (1979). Population biology of infectious diseases: Part I. Nature, London 280, 361–7.
Anderson, R. M., Whitfield, P. J. & Dobson, A. P. (1978). Experimental studies on infection dynamics: infection of the definitive host by the cercariae of Transversotrema patialense. Parasitology 77, 189200.
Bailey, N. T. J. (1964). The Elements of Stochastic Processes. London: John Wiley.
Bartlett, M. S. (1960). Stochastic Population Models in Ecology and Epidemiology. London: Methuen.
Boxshall, G. A. (1974). The population dynamics of Lepeoptheirus pectoralis (Muller): dispersion patterns. Parasitology 69, 373–90.
Campbell, A., Ward, R. A. & Garrie, M. B. (1980). Seasonal activity and frequency distributions of ticks (Acari: Ixodidae) infesting snowshoe hares in Nova Scotia, Canada. Journal of Medical Entomology 17, 22–9.
Cox, D. R. & Miller, H. D. (1965). The Theory of Stochastic Processes. London: Methuen.
Crofton, H. D. (1971 a). A quantitative approach to parasitism. Parasitology 62, 179–94.
Crofton, H. D. (1971 b). A model of host–parasite relationships. Parasitology 63, 343–64.
Gordon, D. M. & Rau, M. E. (1982). Possible evidence for mortality induced by the parasite Apatemon gracilis in a population of brook sticklebacks Culaea inconstans. Parasitology 84, 41–7.
Henricson, J. (1977). The abundance and distribution of Diphyllobothrium dentriticum (Nitzsch) and D. ditremum (Creplin) in the char Salvelinus alpinus. Journal of Fish Biology 11, 231–48.
Jarroll, E. L. Jr. (1979). Population biology of Bothriocephalus rarus Thomas (1937) in the red-spotted newt, Notophthalmus viridescens Raf. Parasitology 79, 183–93.
Kennedy, C. R. & Burrough, R. (1977). The population biology of two species of eyefluke, Diplostomum gasterostei and Tylodelphys clavata in perch. Journal of Fish Biology 11, 619–33.
Keymer, A. E. & Anderson, R. M. (1979). The dynamics of infection of Tribolium confusum by Hymenolepis diminuta: the influence of infective stage density and spatial distribution. Parasitology 79, 195207.
May, R. M. (1975). Stability and Complexity in Model Ecosystems, 2nd ed.Princeton: Princeton University Press.
May, R. M. (1977). Dynamical aspects of host–parasite associations: Crofton's model revisited. Parasitology 75, 259–76.
May, R. M. & Anderson, R. M. (1978). Regulation and stability of host–parasite population interactions. II. Destabilizing processes. Journal of Animal Ecology 47, 249–68.
May, R. M. & Anderson, R. M. (1979). Population biology of infectious diseases: Part II. Nature, London 280, 455–61.
Pennycuick, L. (1971). Frequency distributions of parasites in a population of three-spined sticklebacks, Gasterosteus aculeatus L.. with particular reference to the negative binomial distribution. Parasitology 63, 389406.
Pielou, E. C. (1969). An Introduction to Mathematical Ecology. New York: Wiley Interscience.
Randolph, S. E. (1975). Patterns of distribution of the tick Ixodes trianguliceps Birula on its hosts. Journal of Animal Ecology 44, 451–74.
Rutledge, L. C., Ward, R. A. & Buckwalter, R. M. (1973). Plasmodium spp: Dispersion of malarial oocyst populations in Anopheline and Culicine mosquitoes. Experimental Parasitology 34, 132–41.
Schmid, W. D. & Robinson, E. J. (1972). The pattern of a host–parasite distribution. Journal of Parasitology 57, 907–10.
Taylor, L. R. (1961). Aggregation, variance and the mean. Nature, London 189, 732–5.
Taylor, L. R. & Taylor, R. A. J. (1977). Aggregation, migration and population dynamics. Nature, London 265, 415–21.
Taylor, L. R. & Woiwood, I. P. (1980). Temporal stability as a density-dependent species characteristic. Journal of Animal Ecology 49, 209–24.
Taylor, L. R., Woiwood, I. P. & Perry, J. N. (1978). The density dependence of spatial behaviour and the rarity of randomness. Journal of Animal Ecology 47, 383406.
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  • ISSN: 0031-1820
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