Ways to wing it: correlation of wing shape with habitat preferences, toxicity and migration in butterflies
Ecology, Evolution and Organismal Biology
The shape of a wing influences the airflow over its surface and governs the aerodynamic forces acting on the wing. Therefore, wing shape is tightly correlated with flight performance. For bats and birds, faster fliers generally have more slender and elongated wings (high aspect ratio), while slower fliers have more broad and short wings (low aspect ratio). The preferred flight speed, and therefore wing shape of an animal is usually adapted to its habitat, foraging strategy, and flight behavior. We examined the relationship of aspect ratio and wing shape (i.e., leading edge curvature and wing pointiness) of butterfly forewings, relative to habitat preferences, toxicity, and migration using geometric morphometrics. Pictures of 22 butterfly species from three different habitats (forest, open forest and open habitat) were digitized and analyzed using morphometric methods. Our preliminary results indicate that the previously shown relationship of wing shape and flight performance for larger fliers might not scale down to butterflies. We found a significant difference in aspect ratios for butterflies in different habitats. Suspected slower fliers had a higher aspect ratio than faster fliers. This could mean that we need to adjust our ecological interpretation of wing shapes for small fliers such as butterflies.