Extreme elevational migration spurred cryptic speciation in giant hummingbirds

What is it about?

The distributions of species tend to be constrained to limited climatic ranges, which contributes to the maintenance of biodiversity across ecosystems. In contrast, giant hummingbirds (Patagona spp.) are found across an unusually large breadth of latitude and elevation in the Andes Mountains. We analyzed the movements, respiratory traits, and population genomics of giant hummingbirds to explore the origins of the species’ exceptionally broad environmental niche. Tracking devices attached to eight giant hummingbirds documented annual circular migrations across the Central Andean Plateau spanning over 8,300 kilometers. A 3-week period during migration included an ascent of around 4,100 meters in elevation, undertaken in bursts similar to acclimatizing human mountaineers. Genomic sequencing of 101 giant hummingbirds showed that they comprise two separate species: the southern, migratory P. gigas and a northern, nonmigratory species Patagona chaski sp. nov. The two species diverged 2.1–3.4 million years ago via a gain or loss of migratory behavior. Thus, the climatic niche range of giant hummingbirds is not as anomalously broad as previously thought, due to previously unidentified cryptic speciation. According to the authors, the results illustrate how changes in migratory behavior can expand climatic niche ranges and drive subsequent speciation.

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Photo by Paul Daly on Unsplash

Photo by Paul Daly on Unsplash

Why is it important?

We document the world's longest hummingbird migratory journey and describe the world's largest hummingbird species.