, Volume 144, Issue 1, pp 148–156 | Cite as

Altered parasite assemblages in raccoons in response to manipulated resource availability

  • Amber N. Wright
  • Matthew E. Gompper
Community Ecology


The role that host aggregation plays in structuring parasite assemblages was examined by experimentally increasing the contact rates of raccoons, Procyon lotor. Two populations of raccoons in southern New York were monitored for 2 years to determine baseline levels of host interaction and to identify the parasite assemblage. In the third year of the study, one population was provisioned with the addition of clumped food resources, while the other was provisioned with equal quantities of dispersed food resources. Remote photography showed that raccoons aggregated at clumped resources but not at dispersed resources, and therefore contact rates between individuals were higher in the site with clumped resources. There were no differences in parasitism between the sites prior to resource augmentation. Among ectoparasites, there were no significant changes in the prevalence or abundance of any species in response to the perturbation. In contrast, across the endoparasite assemblage within and across hosts, the prevalence of infection increased as a result of increased host contact. Strong increases in the prevalence of a few directly transmitted species and slight increases among most species lead to increased evenness in parasite prevalence, suggesting that parasites in this system are transmission limited. In addition, the number of parasite species per host (the parasite infracommunity) was higher in the clumped-resource population. These endoparasite results suggest that intraspecific variation in the species richness of parasite communities of individual hosts, and the prevalence of parasitic species in host populations as assessed across entire parasitic assemblages, is robustly influenced by intraspecific variation in the degree of host contact. Further, these results suggest that anthropogenic changes which alter resource availability may have important consequences for disease transmission in wildlife.


Community structure Resource manipulation Contact rates Disease transmission Baylisascaris procyonis 



This work benefited from the aid of C. Fiorello, R. Goodman, H. Fener, P. Macchia, K. McFadden, C. Scully, R. Kays, W. Schuster, J.C. Morales, J. Brady, B. Brady, M. Munson, and P. Miller. Insights from Dr. S. Wade and the Cornell University Veterinary Diagnostic Laboratory were critical for parasite identification. Research was supported by the Black Rock Forest Consortium, AMNH Theodore Roosevelt Memorial Fund, and NSF (DEB-0347609). All research was approved by the New York State Department of Environmental Conservation and Columbia University (IACUC protocol no. 343).

Supplementary material


  1. Allan SA (2001) Ticks (Class Arachnida: Order Acarina). In: Samuel WM, Pybus MJ, Kocan AA (eds) Parasitic diseases of wild mammals, 2nd edn. Iowa State Press, Ames Iowa, pp 72–106Google Scholar
  2. Anderson RM (1991) Populations and infectious diseases: ecology or epidemiology? J Anim Ecol 60:1–50CrossRefGoogle Scholar
  3. Anderson RM, May RM (1979) Population biology of infectious diseases: part 1. Nature 280:361–367CrossRefPubMedGoogle Scholar
  4. Anderson RM, May RM (1991) Infectious diseases of humans: dynamics and control. Oxford University Press, OxfordGoogle Scholar
  5. Anderson RM, Jackson HC, May RM, Smith AM (1981) Population dynamics of fox rabies in Europe. Nature 289:765–771CrossRefPubMedGoogle Scholar
  6. Barclay RM (1988) Variation in the costs, benefits, and frequency of nest reuse by barn swallows (Hirundo rustica). Auk 105:53–60Google Scholar
  7. Bowman DD (1999) Georgis‘ parasitology for veterinarians, 7th edn. WB Saunders Company, PhiladelphiaGoogle Scholar
  8. Bush AO, Lafferty KD, Lotz JM, Shostak AW (1997) Parasitology meets ecology on its own terms: Margolis et al revisited. J Parasitol 83:575–583PubMedCrossRefGoogle Scholar
  9. Côté IM, Gross MR (1993) Reduced disease in offspring: a benefit of coloniality in sunfish. Behav Ecol Sociobiol 33:269–274CrossRefGoogle Scholar
  10. Carr GM, Macdonald DW (1986) The sociality of solitary foragers: a model based on resource dispersion. Anim Behav 34:1540–1579CrossRefGoogle Scholar
  11. Childs JE, Curns AT, Dey ME, Real AL, Rupprecht CE, Krebs JW (2001) Rabies epizootics among raccoons vary along a North-South gradient in the eastern United States. Vector-Borne Zoonot 1:253–267CrossRefGoogle Scholar
  12. Daszak P, Cunningham AA, Hyatt AD (2000) Emerging infectious diseases of wildlife—threats to biodiversity and human health. Science 287:443–449CrossRefPubMedGoogle Scholar
  13. Davies CR, Ayres JM, Dye C, Deane LM (1991) Malaria infection rate of Amazonian primates increases with body weight and group size. Funct Ecol 5:655–662CrossRefGoogle Scholar
  14. Fish D, Dowler RC (1989) Host associations of ticks (Acari: Ixodidae) parasitizing medium-sized mammals in a Lyme disease endemic area of southern New York. J Med Entomol 26:200–209PubMedGoogle Scholar
  15. Freeland WJ (1979) Primate social groups as biological islands. Ecology 60:719–728CrossRefGoogle Scholar
  16. Gehrt SD, Fritzell KE (1998) Resource distribution, female home range dispersion and male spatial interactions: group structure in a solitary carnivore. Anim Behav 55:1121–1227CrossRefGoogle Scholar
  17. Gompper ME, Wright AN. Altered prevalence of raccoon roundworm, Baylisascaris procyonis, due to manipulated contact rates of hosts. J Zool (in press)Google Scholar
  18. Hartup BK, Mohammed HO, Kollias GV, Dohndt AA (1998) Risk factors associated with mycoplasmal conjunctivitis in house finches. J Wildl Dis 34:281–288PubMedGoogle Scholar
  19. Hochberg ME (1991) Viruses as costs to gregarious feeding behaviour in the Lepidoptera. Oikos 61:291–296CrossRefGoogle Scholar
  20. Keymer AE, Read AF (1991) Behavioural ecology: the impact of parasitism. In: Toft CA, Aeschlimann A, Bolis L (eds) Parasite-host associations. Oxford University Press, Oxford, pp 37–61Google Scholar
  21. Kiesecker JM, Skelly DK, Beard KH, Preisser E (1999) Behavioral reduction of infection risk. Proc Natl Acad Sci USA 96:9165–9168CrossRefPubMedGoogle Scholar
  22. Lewis SE (1996) Low roost-site fidelity in pallid bats: associated factors and effect on group stability. Behav Ecol Sociobiol 39:335–344CrossRefGoogle Scholar
  23. Møller AP, Dufva R, Allander K (1993) Parasites and the evolution of host social behavior. Adv Stud Behav 22:65–102CrossRefGoogle Scholar
  24. Moore J (2001) Parasites and the behavior of animals. Oxford series in ecology and evolution. Oxford University Press, OxfordGoogle Scholar
  25. Mooring MS, Hart BL (1992) Animal grouping for protection from parasites: selfish herd and encounter-dilution effects. Behaviour 123:173–193Google Scholar
  26. Mouritsen KN, Poulin R (2002) Parasitism, community structure and biodiversity in intertidal ecosystems. Parasitology 124:S101–S117PubMedCrossRefGoogle Scholar
  27. Page KL, Swihart RK, Kazacos KR (1998) Raccoon latrine structure and its potential role in transmission of Baylisascaris procyonis to vertebrates. Am Midl Nat 140:180–185CrossRefGoogle Scholar
  28. Prange S, Gehrt SD, Wiggers EP (2003) Demographic factors contributing to high raccoon densities in urban landscapes. J Wildl Manage 67:324–333CrossRefGoogle Scholar
  29. Rubenstein DI, Hohmann ME (1989) Parasites and social behavior of island feral horses. Oikos 55:312–320CrossRefGoogle Scholar
  30. Smith EP (2002) BACI design. In: El-Shaarawi AH, Piegorsch WW (eds) Encyclopedia of environmetrics. Wiley, Chichester, pp 141–148Google Scholar
  31. Stewart-Oaten A, Murdoch WW, Parker KR (1986) Environmental impact assessment: “pseudoreplication” in time? Ecology 67:929–940CrossRefGoogle Scholar
  32. Totton SC, Tinline RR, Rosatte RC, Bigler LL (2002) Contact rates of raccoons (Procyon lotor) at a communal feeding site in rural eastern Ontario. J Wildl Dis 38:313–319PubMedGoogle Scholar
  33. Wright AN (2002) Changes in raccoon (Procyon lotor) parasite communities in response to an experimental manipulation of resource availability. Thesis, Columbia University, New YorkGoogle Scholar

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.Center for Population BiologyUniversity of CaliforniaDavisUSA
  2. 2.Department of Fisheries and Wildlife SciencesUniversity of MissouriColumbiaUSA

Personalised recommendations