title: When parasites become prey: ecological and epidemiological significance of eating parasites.
abstract: Recent efforts to include parasites in food webs have drawn attention to a previously ignored facet of foraging ecology: parasites commonly function as prey within ecosystems. Because of the high productivity of parasites, their unique nutritional composition and their pathogenicity in hosts, their consumption affects both food-web topology and disease risk in humans and wildlife. Here, we evaluate the ecological, evolutionary and epidemiological significance of feeding on parasites, including concomitant predation, grooming, predation on free-living stages and intraguild predation. Combining empirical data and theoretical models, we show that consumption of parasites is neither rare nor accidental, and that it can sharply affect parasite transmission and food web properties. Broader consideration of predation on parasites will enhance our understanding of disease control, food web structure and energy transfer, and the evolution of complex life cycles.
authors.affiliation: Ecology and Evolutionary Biology, University of Colorado, Ramaley N122, Campus Box 334, Boulder, CO 80309, USA. pieter.johnson@colorado.edu
authors.forename: Pieter T J
authors.initials: PT
authors.lastname: Johnson
authors.forename: Andrew
authors.initials: A
authors.lastname: Dobson
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Lafferty
authors.forename: David J
authors.initials: DJ
authors.lastname: Marcogliese
authors.forename: Jane
authors.initials: J
authors.lastname: Memmott
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Orlofske
authors.forename: Robert
authors.initials: R
authors.lastname: Poulin
authors.forename: David W
authors.initials: DW
authors.lastname: Thieltges
mesh_terms: D000818:Animals; D020387:Food Chain; D010271:Parasites; D011235:Predatory Behavior