Data from: Post-glacial northward expansion and genetic differentiation between migratory and sedentary populations of the broad-tailed hummingbird (Selasphorus platycercus)

Unlike other migratory hummingbirds in North America, the broad-tailed
hummingbird (Selasphorus platycercus) exhibits both long-distance
migratory behaviour in the USA and sedentary behaviour in Mexico and
Guatemala. We examined the evolution of migration linked to its northward
expansion using a multi-perspective approach. We analysed variation in
morphology, mitochondrial and nuclear DNA, estimated migration rates
between migratory and sedentary populations, compared divergence times
with the occurrence of Quaternary climate events, and constructed species
distribution models to predict where migratory and sedentary populations
resided during the Last Glacial Maximum (LGM) and Last Interglacial (LIG)
events. Our results are consistent with a recent northward population
expansion driven by migration from southern sedentary populations.
Phylogeographical analyses and population genetics methods revealed that
migratory populations in the USA and sedentary populations in Mexico of
the platycercus subspecies form one admixed population, and that sedentary
populations from southern Mexico and Guatemala (guatemalae) undertook
independent evolutionary trajectories. Species distribution modelling
revealed that the species is a niche tracker and that the climate
conditions associated with modern obligate migrants in the USA were not
present during the LIG, which provides indirect evidence for recent
migratory behaviour in broad-tailed hummingbirds on the temporal scale of
glacial cycles. The finding that platycercus hummingbirds form one genetic
population and that suitable habitat for migratory populations was
observed in eastern Mexico during the LIG also suggests that the
conservation of overwintering sites is crucial for obligate migratory
populations currently facing climate change effects.