Bird predation selects for wing shape and coloration in a damselfly

Area of Science:

• Evolutionary biology
• Animal behavior
• Ecology

Background:

• Wing shape and coloration influence flight performance and predation risk.
• Sexual selection often involves conspicuous traits that can increase predation.
• Damselflies (Calopteryx splendens) exhibit intra- and intersexual selection on wing color patches.

Purpose of the Study:

• To investigate how predation by white wagtails (Motacilla alba) affects wing shape and wing color patch size in male banded demoiselle damselflies.
• To test predictions that selection favors short, broad wings for escape and reduced wing patch size.
• To understand the differential selection on forewings and hindwings.

Main Methods:

• Field study comparing wings of live damselflies with those of predated individuals.
• Analysis of wing shape using aerodynamic principles and previous studies on damselfly territoriality.
• Measurement and comparison of wing color patch size between live and predated individuals.

Main Results:

• Selection favored a slender forewing shape, contrary to predictions.
• Selection favored the predicted short and broad wing shape in hindwings.
• Selection favored a narrower wing color patch size.

Conclusions:

• Forewings and hindwings experience different selective pressures, suggesting distinct roles in flight (sustained flight vs. maneuverability).
• Predation can influence both morphological and coloration traits related to flight and display.
• Selection pressures can vary spatially, even in seemingly simple predator-prey systems.