The Red Postman (Heliconius erato) is a widespread tropical butterfly of Central and South America, instantly recognizable by its black wings marked with a bold red-orange band across the forewings and, depending on the geographic race, additional streaks of yellow or white, a pattern that varies dramatically across its many regional subspecies while still signaling toxicity to predators. Like its Heliconius relatives, its caterpillars feed solely on passionflower vines, sequestering cyanogenic compounds that make both larvae and adults unpalatable, and adults further extend their lifespan to several months by supplementing nectar with pollen for extra protein. It's a textbook example of Müllerian mimicry, having evolved nearly identical wing patterns to the unrelated but similarly toxic Heliconius melpomene across much of their shared range, so that predators learn to avoid both species faster; the two are so alike that they're often mistaken for one another despite being genetically distinct. Found in forest edges, clearings, and gardens from Mexico to Argentina, the Red Postman displays the characteristic slow, fluttering Heliconius flight, forms communal nighttime roosts, and is well known among researchers as one of the most extensively studied butterflies for understanding speciation, mimicry, and hybrid zones in the wild.
