Wire ingestion by a red-billed tropicbird Phaethon aethereus chick on San Pedro Mártir Island, Mexico

We report the ingestion of wire by a Red-billed Tropicbird Phaethon aethereus chick at San Pedro Mártir Island, Gulf of California, Mexico. A scat sample collected from a four- to five-week-old chick contained a copper wire ~5.0 mm in length. Biologging revealed the previous foraging trips by one of the parents, and we ascertained the diet of birds in this colony through a molecular approach. From these data, we suggest why this individual was fed wire.