White-tailed Tropicbird vs Red-billed Tropicbird

In short

The bill color is the most reliable field mark: the White-tailed Tropicbird has a yellow-orange bill, while the Red-billed Tropicbird has a red bill. Both species have long tail streamers, but the White-tailed Tropicbird's are entirely white, whereas the Red-billed Tropicbird's tail is white with black edges.

Identification tips

1. Check the bill color: yellow-orange for White-tailed, red for Red-billed. 2. Look at the tail streamers: entirely white for White-tailed, white with black edges for Red-billed. 3. Note the wing markings: more extensive black on wings and a black eye stripe for Red-billed. 4. Both species are often seen flying over open ocean, so location alone may not help.

Size

Both species are similar in size, with slender bodies and long tail streamers.

Plumage

The White-tailed Tropicbird has mostly white plumage with some black markings on the wings. The Red-billed Tropicbird also has white plumage but with more extensive black markings on the wings and a black eye stripe.

Behaviour

Both species are pelagic and are often seen flying over the ocean, sometimes investigating boats. They are plunge-divers, feeding on flying fish and squid.

Habitat

Both species inhabit tropical and subtropical seas, often far from land, except during breeding when they return to nesting islands.

Voice

Vocalizations are not a primary distinguishing feature between these species in the field.