Wing shape differences along a migration route of the long-distance migrant Globe Skimmer DragonflyPantala flavescens

Frank Johansson,R Charles Anderson,Francy K Kakkassery,Prathapan K Divakaran,Tobias Kollberg Hedström

doi:10.1017/s0266467421000444

Frank Johansson, R Charles Anderson + Show 3 more

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https://doi.org/10.1017/s0266467421000444

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Abstract

AbstractAnimals which migrate by flying should be subject to selection for optimal wing characteristics that maximize energy efficiency during migration. We investigated wing shape and wing area variation in the Globe Skimmer DragonflyPantala flavescens, which has the longest known migration of any insect. Wing shape and wing area differences between individuals in southern Peninsular India, and migrating individuals at a stop-over site on the Maldives, were compared. Results suggest that individuals which successfully reached the Maldives, on their way from India to Africa, had a broader wing base and an overall more slender wing shape than individuals in southern India. Contrary to our expectations, wing area did not differ significantly in most of our comparisons between southern India and the Maldives, suggesting that wing shape is more important than wing area for successful migration inP. flavescens. The results provide indirect evidence of natural selection on wing shape in a migrating dragonfly.

Highlights

Animal migration, the more or less regular movement of animals to or from a particular geographic area, is a widespread phenomenon and is often associated with seasonality (Dingle 1996)
Though front and hind wing shapes are different, the pattern of difference in the shape of hind wings between those caught in Kerala and the Maldives was similar to that of the front wings (Figure 2)
Male hind wing more pointed outer tip compared to those from Kerala. This pattern of wing shape differences was seen in samples from both 2010 and 2018

Summary

Introduction

The more or less regular movement of animals to or from a particular geographic area, is a widespread phenomenon and is often associated with seasonality (Dingle 1996). Comparative studies have found indirect evidence that wing shape is under selection since many migrating populations and species have longer and/or more slender wings than non-migrating ones (Calmaestra and Moreno 2001, Johansson et al 2009, Baldwin et al 2010, Suarez-Tovar & Sarmiento 2016, Freedman and Dingle 2018). An alternative indirect approach to study such selection would be to compare wing shape and wing area in a population before and after completing migration (Yang et al 2016, Flockhart et al 2017). We use this approach here with a migratory dragonfly as our study organism

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