Green Leaves, Red Flags: Host Plant Associations as Indicators of Prey Defense for an Avian Predator
Defended prey are often thought to rely on conspicuous warning signals to distinguish themselves from undefended prey, facilitating predator learning and avoidance. Yet many chemically defended organisms are inconspicuous and difficult to distinguish from palatable prey, raising a fundamental question: how do predators avoid defended prey when prey themselves provide little or no reliable signals…
Green leaves and red flags: Host plant associations help predators distinguish chemically defended prey from undefended ones, according to a study on Carolina wrens and two types of caterpillars. Wrens quickly changed their search behavior and attack decisions solely based on the host plant they encountered, with defended prey receiving substantially less attention.
When plants were absent, the advantage of discriminating between prey types disappeared, leading to more attacks on both types. Host plant clustering also affected predator behavior, with strongly clustered plants attracting fewer visits from predators. These findings suggest that warning signals may not solely rely on a prey's appearance, but also on the ecological context provided by host plants, including their identity and spatial distribution.
This challenges the notion that aposematism relies solely on prey phenotype and highlights the importance of ecological context in the evolution and maintenance of warning systems.
Written by urgent.news from bioRxiv's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
