title: Field estimates of reproductive success in a model insect: behavioural surrogates are poor predictors of fitness.
abstract: Understanding, and therefore measuring, factors that determine fitness is a central problem in evolutionary biology. We studied a natural population of Coenagrion puella (Odonata: Zygoptera) over two entire breeding seasons, with over a thousand individuals uniquely marked and genotyped, and all mating events at the rendezvous site recorded. Using a parentage analysis, fitness of individuals in the first generation was quantified as the numbers of offspring that survived to maturity. Although mating behaviour can be predicted by environmental and demographical variables, the numbers of mature offspring produced (fitness) cannot, and crucially, are poorly correlated with behavioural observations of mating. While fitness of both sexes was positively related to mating behaviour and to female's ectoparasite burden, these behavioural observations explained little more variance in offspring production than environmental and demographical variables. Thus, we demonstrate that behavioural measures of reproductive success are not necessarily reliable estimates of fitness in natural populations.
authors.affiliation: University of Liverpool, Department of Evolution, Ecology and Behaviour, Biosciences Building, Crown Street, Liverpool, L69 7ZB, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Thompson
authors.forename: Christopher
authors.initials: C
authors.lastname: Hassall
authors.forename: Chris D
authors.initials: CD
authors.lastname: Lowe
authors.forename: Phillip C
authors.initials: PC
authors.lastname: Watts
mesh_terms: D000818:Animals; D004739:England; D005260:Female; D056084:Genetic Fitness; D005828:Genetics, Population / Q000379:methods*; D007313:Insecta / Q000502:physiology*; D008297:Male; D012098:Reproduction; D012726:Sexual Behavior, Animal