Data from: Predator-mediated natural selection on the wings of the damselfly Calopteryx splendens: differences in selection among trait types

Traits that increase mating success in males may come at a cost, such as
an increased risk of predation. However, predator-mediated selection is
challenging to document in natural populations, hampering our
understanding of the trade-offs between sexual selection and predation.
Here we report on a study of predator-mediated natural selection on wing
traits in the damselfly Calopteryx splendens, the males of which possess
conspicuous wing patches. Wagtails (genus Motacilla) are important avian
predators of C. splendens, capturing them in flight and removing the wings
prior to consumption. Using geometric morphometric techniques, we
quantified the strength and mode of selection on wing traits by comparing
wings from depredated individuals with the standing variation present in
the population. Our results reveal that predator-mediated selection is
stronger on secondary sexual characters than on size and shape, suggesting
that traits related to flight performance are closer to their adaptive
peaks. This could be a consequence of the long-term evolutionary
association with avian predators, whereas stronger selection on
conspicuous secondary sexual traits may reflect trade-offs between sexual
and natural selection. Finally, even though C. splendens possesses nearly
identical fore- and hindwings, we found evidence for divergent selection
between them.