White-tailed Tropicbird

How to find it

Sightings are chance events, so no reliable site exists. Any tropicbird is most likely to be met on an ocean crossing to Cocos Island, where the Red-billed Tropicbird is the most often recorded. On the Caribbean coast near Tortuguero, the one mainland bird was seen flying over a pasture, so a white bird with a very long tail overhead is worth a careful look. Check the back and bill colour before naming it.

How to recognise it

It is the smallest of the tropicbirds. Adults show these marks:

- mostly white plumage

- a black eye mask

- a black bar on the inner wing

- black wingtips

- a yellow to orange bill

- a very long white tail streamer

The observer at Tortuguero described a large, white, tern-like bird with fast wingbeats and a very long white tail. It had black wingtips, a white back and a black band across the upper wing.

Juveniles look different. They have a grey or yellow-green bill and no long tail streamers, and their backs are finely barred with black. A pure white back with no barring marks an adult-type bird. The Tortuguero bird was an after-first-cycle individual, so not an adult in full plumage.

Behaviour and diet

This is mainly an ocean bird that wanders widely, and both adults and juveniles can travel up to 1,000 km. In some areas it visits coasts more than other tropicbirds do. The authors of the Tortuguero record think that bird was either a wanderer visiting the coast to feed or a vagrant blown inland by strong winds.

It eats mainly flying fish, squid and crabs. It plunge-dives from up to 20 m, but it catches flying fish in flight, and it usually feeds in pairs.

Where it lives

Across its range it lives over tropical oceans in the Atlantic, western Pacific and Indian Oceans. It breeds on islands, laying a single egg on the ground or a cliff ledge.

In Costa Rica there is no breeding population. Seabird records here have mostly come from the coasts and from Isla del Coco National Park. The White-tailed Tropicbird has been documented at Cocos Island in the Pacific and on the Caribbean side near Tortuguero in Limón province.

Similar birds

Costa Rica has three tropicbirds. The Red-billed Tropicbird has a red bill and no black wing bar, while the White-tailed has a pure white back and a yellow-orange bill. Juvenile and Red-billed Tropicbirds both have a barred back, which helps separate them from an adult-type White-tailed. The third, the Red-tailed Tropicbird, is also on the Costa Rica list as accidental.

Names and lore in Costa Rica

The official Costa Rican Spanish name is Rabijunco Cola Blanca. A Costa Rican bird-watching site spells it slightly differently, as Rabijunco Coli Blanca. Elsewhere in Latin America it is also called rabijunco coliblanco or rabijunco común, and in Cuba contramaestre. The scientific name comes from Greek: Phaethon means bright, and lepturus joins words for thin and tail, so it means roughly bright one with a thin tail.

Status and conservation

The AOCR list gives it status A, accidental, the Avibase Costa Rica checklist treats it as rare or accidental, and worldwide the IUCN lists it as Least Concern.