Parasite infections in a social carnivore: Evidence of their fitness consequences and factors modulating infection load.

Autor: Ferreira SCM; Department of Ecological Dynamics Leibniz Institute for Zoo and Wildlife Research Berlin Germany., Hofer H; Department of Ecological Dynamics Leibniz Institute for Zoo and Wildlife Research Berlin Germany.; Department of Veterinary Medicine Freie Universität Berlin Berlin Germany.; Department of Biology, Chemistry and Pharmacy Freie Universität Berlin Berlin Germany., Madeira de Carvalho L; Centre for Interdisciplinary Research in Animal Health (CIISA), Faculdade de Medicina Veterinaria Universidade de Lisboa Lisbon Portugal., East ML; Department of Ecological Dynamics Leibniz Institute for Zoo and Wildlife Research Berlin Germany.
Jazyk: angličtina
Zdroj: Ecology and evolution [Ecol Evol] 2019 Jul 11; Vol. 9 (15), pp. 8783-8799. Date of Electronic Publication: 2019 Jul 11 (Print Publication: 2019).
DOI: 10.1002/ece3.5431
Abstrakt: There are substantial individual differences in parasite composition and infection load in wildlife populations. Few studies have investigated the factors shaping this heterogeneity in large wild mammals or the impact of parasite infections on Darwinian fitness, particularly in juveniles. A host's parasite composition and infection load can be shaped by factors that determine contact with infective parasite stages and those that determine the host's resistance to infection, such as abiotic and social environmental factors, and age. Host-parasite interactions and synergies between coinfecting parasites may also be important. We test predictions derived from these different processes to investigate factors shaping infection loads (fecal egg/oocyte load) of two energetically costly gastrointestinal parasites: the hookworm Ancylostoma and the intracellular Cystoisospora , in juvenile spotted hyenas ( Crocuta crocuta ) in the Serengeti National Park, in Tanzania. We also assess whether parasite infections curtail survival to adulthood and longevity. Ancylostoma and Cystoisospora infection loads declined as the number of adult clan members increased, a result consistent with an encounter-reduction effect whereby adults reduced encounters between juveniles and infective larvae, but were not affected by the number of juveniles in a clan. Infection loads decreased with age, possibly because active immune responses to infection improved with age. Differences in parasite load between clans possibly indicate variation in abiotic environmental factors between clan den sites. The survival of juveniles (<365 days old) to adulthood decreased with Ancylostoma load, increased with age, and was modulated by maternal social status. High-ranking individuals with low Ancylostoma loads had a higher survivorship during the first 4 years of life than high-ranking individuals with high Ancylostoma loads. These findings suggest that high infection loads with energetically costly parasites such as hookworms during early life can have negative fitness consequences.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Databáze: MEDLINE