# UKBirds

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## Red-Billed Tropicbird

### Phaethon aethereus

The Red-billed Tropicbird, Phaethon aethereus, also known as the Boatswain Bird is a tropicbird, one of three closely related seabirds of tropical oceans.
The adult is a slender, mainly white bird, 48 cm long, excluding the central tail feathers which double the total length, and a one metre wingspan. The long wings have black markings on the flight feathers. There is black through the eye. The bill is red. Sexes are similar, although males average longer tails. Juveniles lack the tail streamers, are greyer-backed, and have a yellow bill. P. a. indicus has a reduced black eye stripe, and a more orange-tinted bill.