The antipredator benefits of postural camouflage in peppered moth caterpillars

• Published in: Scientific reports Vol. 10; no. 1; pp. 21654 - 8
• Main Authors: Rowland, Hannah M., Burriss, Robert P., Skelhorn, John
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 10-12-2020; Nature Publishing Group; Nature Portfolio
• Subjects: 631/158; 631/158/856; 631/181; 631/601/1466; 631/601/18; Ambient temperature; Animal behavior; Animals; Anti-predator behavior; Biological Evolution; Butterflies & moths; Camouflage; Dietary restrictions; Food availability; Humanities and Social Sciences; Larva - physiology; Larvae; Mimicry; Moths - growth & development; Moths - physiology; multidisciplinary; Natural selection; Pigmentation; Posture; Predators; Predatory Behavior; Prey; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-78686-4

Camouflage is the most common form of antipredator defense, and is a textbook example of natural selection. How animals’ appearances prevent detection or recognition is well studied, but the role of prey behavior has received much less attention. Here we report a series of experiments with twig-mimicking larvae of the American peppered moth
Biston betularia
that test the long-held view that prey have evolved postures that enhance their camouflage, and establish how food availability and ambient temperature affect these postures. We found that predators took longer to attack larvae that were resting in a twig-like posture than larvae resting flat against a branch. Larvae that were chilled or food restricted (manipulations intended to energetically stress larvae) adopted a less twig-like posture than larvae that were fed ad libitum. Our findings provide clear evidence that animals gain antipredator benefits from postural camouflage, and suggest that benefits may come at an energetic cost that animals are unwilling or unable to pay under some conditions.