Benefits of Induced Host Responses against an Ectoparasite

Heeb, P; Werner, I; Kolliker, M; Richner, Heinz (1998). Benefits of Induced Host Responses against an Ectoparasite. Proceedings of the Royal Society. Series B - biological sciences, 265(1390), pp. 51-56. London: Royal Society of London 10.1098/rspb.1998.0263

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As a consequence of the deleterious effects of parasites on host fitness, hosts have evolved responses to minimize the negative impact of parasite infection. Facultative parasite-induced responses are favoured when the risk of infection is unpredictable and host responses are costly. In vertebrates, induced responses are generally viewed as being adaptive, although evidence for fitness benefits arising from these responses in natural host populations is lacking. Here we provide experimental evidence for direct reproductive benefits in flea-infested great tit nests arising from exposure during egg production to fleas. In the experiment we exposed a group of birds to fleas during egg laying (the exposed group), thereby allowing for induced responses, and kept another group free of parasites (the unexposed group) over the same time period. At the start of incubation, we killed the parasites in both groups and all nests were reinfested with fleas. If induced responses occur and are adaptive, we expect that birds of the exposed group mount earlier responses and achieve higher current reproductive success than birds in the unexposed group. In agreement with this prediction, our results show that birds with nests infested during egg-laying have (i) fewer breeding failures and raise a higher proportion of hatchlings to hedging age; () offspring that reach greater body mass, grow longer feathers, and hedge earlier, and (iii) a higher number of recruits and first-year grandchildren than unexposed birds. Flea reproduction and survival did not differ significantly between the two treatments. These results provide the first evidence for the occurrence and the adaptiveness of induced responses against a common ectoparasite in a wild population of vertebrates. [References: 50]

Item Type:

Journal Article (Original Article)


08 Faculty of Science > Department of Biology > Institute of Ecology and Evolution (IEE) > Evolutionary Ecology

UniBE Contributor:

Richner, Heinz




Royal Society of London




Factscience Import

Date Deposited:

04 Oct 2013 14:48

Last Modified:

05 Dec 2022 14:15

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URI: (FactScience: 3176)

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