title: Genetic similarity between mates and extra-pair parentage in three species of shorebirds.
abstract: Matings between close relatives often reduce the fitness of offspring, probably because homozygosity leads to the expression of recessive deleterious alleles. Studies of several animals have shown that reproductive success is lower when genetic similarity between parents is high, and that survival and other measures of fitness increase with individual levels of genetic diversity. These studies indicate that natural selection may favour the avoidance of matings with genetically similar individuals. But constraints on social mate choice, such as a lack of alternatives, can lead to pairing with genetically similar mates. In such cases, it has been suggested that females may seek extra-pair copulations with less related males, but the evidence is weak or lacking. Here we report a strong positive relationship between the genetic similarity of social pair members and the occurrence of extra-pair paternity and maternity ('quasi-parasitism') in three species of shorebirds. We propose that extra-pair parentage may represent adaptive behavioural strategies to avoid the negative effects of pairing with a genetically similar mate.
authors.affiliation: Konrad Lorenz Institute for Comparative Ethology, Austrian Academy of Sciences, Savoyenstrasse 1a, A-1160 Vienna, Austria.
authors.forename: Donald
authors.initials: D
authors.lastname: Blomqvist
authors.forename: Malte
authors.initials: M
authors.lastname: Andersson
authors.forename: Clemens
authors.initials: C
authors.lastname: Küpper
authors.forename: Innes C
authors.initials: IC
authors.lastname: Cuthill
authors.forename: János
authors.initials: J
authors.lastname: Kis
authors.forename: Richard B
authors.initials: RB
authors.lastname: Lanctot
authors.forename: Brett K
authors.initials: BK
authors.lastname: Sandercock
authors.forename: Tamás
authors.initials: T
authors.lastname: Székely
authors.forename: Johan
authors.initials: J
authors.lastname: Wallander
authors.forename: Bart
authors.initials: B
authors.lastname: Kempenaers
mesh_terms: D000220:Adaptation, Biological; D000483:Alleles; D000818:Animals; D001717:Birds / Q000235:genetics / Q000502:physiology*; D016172:DNA Fingerprinting; D005260:Female; D005787:Gene Frequency; D008297:Male; D012098:Reproduction; D012726:Sexual Behavior, Animal; D013045:Species Specificity