A new study led by the University of Sorbonne has found that natural selection imposed by different microhabitats across forest strata can drive adaptive codivergence in wing shapes, flight behaviors, and aerodynamic efficiency among closely related species of Morpho butterflies. These are brightly colored and iconic butterflies that live in tropical Amazon forests.
“The diversity of flying animals suggests that countless combinations of flight morphologies and behaviors have evolved with specific lifestyles, thereby exploiting diverse aerodynamic mechanisms,” wrote the study authors. “How morphology, flight behavior, and aerodynamic properties together diversify with contrasting ecology remains to be elucidated.”
Although insect flight has been studied in great detail in a variety of species, the evolution of flight among closely related species adapted to different habitats is not yet well understood.
Using high-speed videography to observe freely flying butterflies, combined with morphometric analyses and aerodynamic modelling, an international team of scientists investigated codivergences in wing shape, flight behavior, and aerodynamic efficiency among 12 Morpho species living in different forest strata.
The researchers discovered that these species have evolved a diverse set of morphological and behavioral characteristics which differ depending on whether they live in the forests’ understories or canopies. While butterflies occupying cluttered understory habitats displayed more powerful wing-flapping phases that resulted in agile and fast flight, those adapted to open canopy habitats evolved improved and more efficient gliding capacities.
“By comparing canopy and understory species, we show that adaptation to an open canopy environment resulted in increased glide efficiency,” the study authors explained. “Moreover, this enhanced glide efficiency was achieved by different canopy species through distinct combinations of flight behavior, wing shape, and aerodynamic mechanisms, highlighting the multiple pathways of adaptive evolution.”
These findings underline the crucial importance of the habitats that different animal species occupy in shaping their morphology, behavior, and lifestyles.
The study is published in the journal Science.