Early predictors of life‐history events: the link between first feeding date, dominance and seaward migration in Atlantic salmon, Salmo salar L.

TLDR: Earlier-feeding fry were dominant over their later-feeding siblings (controlling for prior residence), despite not being any larger, which led to an increased probability of early-feeding fish migrating to sea at age 1 year (rather than 2 or more), which can translate into a year's difference in the timing of migration.

Abstract: Previous studies have suggested that the earliest fry to emerge from a salmonid redd may have an advantage in the subsequent competition for feeding sites, partly through a ‘prior residence’ effect Here we examined whether there was any relationship between the relative date of first feeding and subsequent dominance status and growth in a sibling group of Atlantic salmon, Salmo salar L, fry Earlier-feeding fry were dominant over their later-feeding siblings (controlling for prior residence), despite not being any larger However, these early fish soon established and then maintained a size advantage This led to an increased probability of early-feeding fish migrating to sea at age 1 year (rather than 2 or more) Thus a difference of less than 1 week in the relative timing of first feeding can translate into a year's difference in the timing of migration