Reproductive senescence and mating tactic interact and conflict to drive reproductive success in a passerine

An understanding of the drivers of individual fitness is a fundamental component of evolutionary ecology and life-history theory. Reproductive senescence, mate and mating tactic choice, and latent heterogeneity in individual quality interact to affect individual fitness. We sought to disentangle the effects of these fitness drivers, where longitudinal data are required to understand their respective impacts. We used reproductive allocation and success data from a long-term (1989-2018) study of white-throated dippers (Cinclus cinclus) in Switzerland to simultaneously examine the effects of female and male age, mating tactic, nest initiation date, and individual heterogeneity on reproductive performance. We modeled quadratic and categorical effects of age on reproductive parameters. The probability of polygyny increased with age in both sexes before declining in older age classes. Similarly, hatching probability in monogamous pairs and the number of nestlings hatched in both monogamous an..., Demographic research on dippers was conducted at three small to medium-sized drainages (Ku¨snacht, Sihl, and Wehrenbach) near the city of Zurich, Switzerland. For 30 years (1989-2018) breeding dippers (30-70 pairs/yr) were marked with metal rings and plastic color markers and associated with nests through resighting of marked individuals and their behavior. Nests were located by carefully searching streams flowing into the northern portion of Lake Zurich from February to June. The mating tactic for each nest was determined through observation of male and female behavior. Previous research has demonstrated low extra-pair paternity in this (<0.01; Becker et al. 2015) and other (<0.02; Øigarden et al. 2010) dipper populations. Reproductive attempts were monitored to cessation, and observers recorded whether or not a nest hatched offspring (γ) and the number of hatchlings from each nest conditional on success (ξ). Nestlings were also marked with metal rings and plastic color markers p..., Required tools: R, JAGS, jagsUI