The Indigo Bunting (*Passerina cyanea*) is a small, strikingly vivid songbird found across much of North America, beloved by birdwatchers for the male's brilliant, almost electric-blue plumage. Interestingly, that dazzling color isn't produced by blue pigment at all — the feathers contain no blue pigment whatsoever, but instead create the appearance of blue through the way their microscopic structure refracts and scatters light, meaning the bird can appear duller or even blackish in poor lighting. Breeding males are a deep, saturated indigo-blue from head to tail, while females are a modest warm brown with faint streaking on their breast — a classic case of sexual dimorphism. They are small birds, roughly the size of a large sparrow, with a short, conical seed-cracking bill. During the breeding season, males are enthusiastic and persistent singers, often belting out their high, sweet, paired-phrase song from exposed perches even during the hottest part of summer days. Indigo Buntings breed across the eastern United States and into the southwest, favoring brushy woodland edges, fields, and roadsides, before migrating to Central America and the Caribbean for winter — a journey they navigate, remarkably, by using the stars as a compass. They are a common and welcome sight at backyard feeders, particularly during migration, when they will readily visit for millet and other small seeds.
