title: Haemoproteus infected birds have increased lifetime reproductive success.
abstract: The impact of haematozoan infection on host fitness has received substantial attention since Hamilton and Zuk posited that parasites are important drivers of sexual selection. However, short-term studies testing the assumption that these parasites consistently reduce host fitness in the wild have produced contradictory results. To address this complex issue, we conducted a long-term study examining the relationship between naturally occurring infection with Haemoproteus and Plasmodium, and lifetime reproductive success and survival of Mountain White-crowned Sparrows. Specifically, we tested the hypothesis that birds infected with haematozoan parasites have reduced survival (as determined by overwinter return rates) and reproductive success. Contrary to expectation, there was no relationship between Haemoproteus and Plasmodium infection and reproduction or survival in males, nor was there a relationship between Plasmodium infection and reproduction in females. Interestingly, Haemoproteus-infected females had significantly higher overwinter return rates and these females fledged more than twice as many chicks during their lifetimes as did uninfected females. We discuss the impact of parasitic infections on host fitness in light of these findings and suggest that, in the case of less virulent pathogens, investment in excessive immune defence may decrease lifetime reproduction.
authors: University of California,San Francisco,1700 4th St,San Francisco,California 94158,USA.
authors: M
authors: M
authors: Zylberberg
authors: Tulane University,6823 St Charles Ave,New Orleans,Louisiana 70118,USA.
authors: E P
authors: EP
authors: Derryberry
authors: University of Montana,32 Campus Dr,Missoula,Montana 59812,USA.
authors: C W
authors: CW
authors: Breuner
authors: University of Western Ontario,1151 Richmond St,London,ON N6A 3K7,Canada.
authors: E A
authors: EA
authors: Macdougall-Shackleton
authors: University of California,Davis,One Shields Avenue,Davis,California 95616,USA.
authors: J M
authors: JM
authors: Cornelius
authors: University of California,Davis,One Shields Avenue,Davis,California 95616,USA.
authors: T P
authors: TP
authors: Hahn
mesh_terms: D000818:Animals; D001715:Bird Diseases / Q000469:parasitology*; D005260:Female; D016787:Haemosporida / Q000469:parasitology* / Q000502:physiology; D006790:Host-Parasite Interactions; D008289:Malaria, Avian / Q000469:parasitology*; D008297:Male; D010961:Plasmodium / Q000469:parasitology / Q000502:physiology; D012098:Reproduction; D046370:Sparrows / Q000469:parasitology*
keywords: Haemoproteus; Mountain White-crowned Sparrow; Plasmodium; Zonotrichia leucophrys oriantha; avian malaria; haematozoa; host fitness; host-parasite interactions; parasite tolerance