SEPTEMBER 10, 2019
by Casey Mcgrath, Society for Molecular Biology and Evolution
Bright colors and conspicuous markings are often used in nature to warn off would-be predators. While we are used to seeing such markings—termed aposematic signals—in plants, caterpillars and snakes, we do not usually think of colorful bird plumage as conveying the same message. However, members of the New Guinea songbird genus Pitohui use their plumage to warn predators that they are toxic.
Aposematic coloration often gives rise to so-called Müllerian mimicry rings, in which multiple toxic species evolve to resemble each other, as a mutual form of protection. The theory is that predators will more quickly learn to avoid all of the species in the ring, with less of a cost to each species. While these rings are common in butterflies and other insects, they are less common among vertebrates where the genetic basis of these traits is often unknown. This is certainly true for pitohuis, one of the few toxic birds on Earth. In a new article in Genome Biology and Evolution titled "Gene flow in the Müllerian mimicry ring of a poisonous Papuan songbird clade (Pitohui; Aves)," an international team of researchers from the National University of Singapore, Biology Centre CAS in the Czech Republic, and the New Guinea Binatang Research Centre set out to unravel the genetic basis and evolutionary history of pitohuis' colorful plumage.