Tracking climatic conditions throughout the year is often assumed to be
an adaptive behavior underlying seasonal migration patterns in animal
populations. In this study, we investigate this hypothesis using genetic
markers data to map migratory connectivity for 22 genetically distinct
bird populations across 6 species. We found that the variation in
seasonal climate tracking at a continental scale is more likely a
consequence, rather than an underlying driver, of migratory
connectivity, which is itself largely shaped by energy efficiency --
i.e. optimizing the balance between accessing available resources and
the cost of movement. However, our results also suggest that
regional-scale seasonal precipitation tracking affects migration
destinations, thus revealing a potential scale-dependency of ecological
processes driving migration. Our results have implications for the
conservation of migratory species under climate change, as populations
that track climate seasonally are potentially at higher risk if they
adapt to a narrow range of climatic conditions.