Data from: Local diversity in phenological responses of migratory lake sturgeon to warm winters

Rich intraspecific diversity in traits that shape responses to
environmental conditions implies that effects of climate change will
differ within species or even populations. Nevertheless, few studies
investigate how different groups within species respond to climatic
fluctuations, and most risk assessments rely upon species-wide
generalizations. We studied effects of among-year variation in air
temperature on the spring migratory phenology of a metapopulation of lake
sturgeon (Acipenser fulvescens) within waters connecting Lake Huron and
Lake Erie of the Laurentian Great Lakes. Sturgeon here express multiple
migratory phenotypes that all spawn in either the St. Clair River or
Detroit River but differ in their use after spawning of more than 86,000
km2 of accessible lake and river habitat. Acoustic tracking over nine
years (2012-2020) revealed mixed phenological responses to late-winter air
temperatures, with three migratory groups arriving at rivers earlier
during warm years and one whose arrival was consistent across years
regardless of temperature. Notably, two groups that spawn in the same
river but overwinter in different lakes entered the river with greater
synchrony during warm years because one advanced its phenology while the
other did not. The results indicated warm weather could alter the dynamics
of the metapopulation and broader community, and exemplify the complexity
hidden beneath broadscale generalizations of species’ response to climate
change.