This is my first PhD paper @imperiallifesci.bsky.social! and absolutely amazing teamwork with @josephtobias.bsky.social, @alexanderlees.bsky.social, Chenyue Yang, and @homewaylin.bsky.social. (8/8)

🚨This paper is #OpenAccess and presents FOUR new global datasets – elevational ranges, flight modes, aerial lifestyle scores, and hand-wing areas for all birds – to facilitate research in ecology & evolution. Download here: doi.org/10.6084/m9.f.... (7/8)

Our results support the ‘thin-air’ hypothesis, suggesting that elevational constraints on flight efficiency are a general mechanism shaping wing evolution in flying animals. (6/8)

We also show that wing-shape gradients are generally steeper at highest elevations, where aerodynamic and physiological challenges are most extreme. (5/8)

The results of phylogenetic analyses on all extant birds confirm that species living at higher elevations have increased wing elongation (hand-wing index) and wing area, even accounting for 8 factors related to climate, habitat and species ecology, including migration. (4/8)

However, testing this idea is not straightforward and previous results are mixed, partly because other factors associated with higher elevation - including elevational migration and differences in foraging ecology – may drive parallel or opposing trends in wing morphology. (3/8)

Flying animals are proposed to have longer and larger wings at higher elevations to provide increased lift and improved flight efficiency, compensating for ‘thin-air’ effects including low air density and low oxygen supply. (2/8)