All birds/Phaethontidae/Red-billed Tropicbird
AI reconstruction of Red-billed Tropicbird (Phaethon aethereus)AI

AI reconstruction created with Nano Banana 2 · 1K, grounded in the profile’s documented taxonomy, habitat, natural-history sources, and an open-license visual reference when available. It is an interpretive image, not documentary evidence. Image policy

PRB-0167Phaethontiformes

Red-billed Tropicbird

Rabijunco Piquirrojo

Phaethon aethereus

Native / natural occurrenceIUCN LC · Least Concern

The red-billed tropicbird (Phaethon aethereus) is a tropicbird, one of three closely related species of seabird of tropical oceans. Superficially resembling a tern in appearance, it has mostly white plumage with some black markings on the wings and back, a black mask and, as its common name suggests, a red bill. Most adults have tail streamers that are about two times their body length, with those in males being generally longer than those in females. The red-billed tropicbird itself has three subspecies recognized, including the nominate. The subspecies mesonauta is distinguished from the nominate by the rosy tinge of its fresh plumage, and the subspecies indicus can be differentiated by its smaller size, more restricted mask, and more orange bill. This species ranges across the tropical Atlantic, eastern Pacific, and Indian Oceans. The nominate is found in the southern Atlantic Ocean, the subspecies indicus in the waters off of the Middle East and in the Indian Ocean, and the subspecies mesonauta in the eastern portions of both the Atlantic and the Pacific Oceans and in the Caribbean. It was one of the many species described by Carl Linnaeus in his 1758 10th edition of Systema Naturae. Nesting takes place in loose colonies, as they nest a scrape found on a cliff face that is easy to take off from. A single egg is laid and is incubated by both sexes for about six weeks. Whether the egg hatches or not can be influenced by pollution and weather, although the latter has a minimal effect on whether a chick fledges or not. After a chick fledges, the parents will usually stop visiting the nest and the chick will leave. Birds of all ages feed on fish and squid, catching them by diving from the air into the water. However, the red-billed tropicbird sometimes follows surface-feeding predators. The predators will drive the prey to the surface, which are then seized by the tropicbird. In some areas, introduced black and brown rats raid nests for eggs and young. Cats also threaten the red-billed tropicbird. This bird is considered to be a least-concern species according to the International Union for Conservation of Nature (IUCN), though populations are thought to be declining. In some places, such as Brazil and Mexico, this bird is considered to be threatened.

FamilyPhaethontidaeTropicbirds
Puerto Rico occurrenceNative / natural occurrenceAvibase inferred core 380
Primary habitatSea cliffs; offshore cays; pelagic watersSea cliffs; offshore cays; pelagic waters
Primary dietFishAquatic predator
Average mass632 gGlobal trait estimate
MovementIrregular / nomadic movements; Sedentary / residentAerial

Sound archive

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XC876607Recording 1 of 3flight call
Spectrogram of Red-billed Tropicbird: flight call
SpectrogramPhaethon aethereus

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Sound recorded by GOUMAND · XC876607 · CC BY-NC-SA 4.0. Visualization by Stichting Xeno-canto voor Natuurgeluiden.

Every recording retains the creator, catalogue number, and license published by Xeno-canto. Metadata via GBIF

Island profile

Catalog scopeAvibase inferred core 380

About the Red-billed Tropicbird

The red-billed tropicbird (Phaethon aethereus) is a tropicbird, one of three closely related species of seabird of tropical oceans. Superficially resembling a tern in appearance, it has mostly white plumage with some black markings on the wings and back, a black mask and, as its common name suggests, a red bill. Most adults have tail streamers that are about two times their body length, with those in males being generally longer than those in females. The red-billed tropicbird itself has three subspecies recognized, including the nominate. The subspecies mesonauta is distinguished from the nominate by the rosy tinge of its fresh plumage, and the subspecies indicus can be differentiated by its smaller size, more restricted mask, and more orange bill. This species ranges across the tropical Atlantic, eastern Pacific, and Indian Oceans. The nominate is found in the southern Atlantic Ocean, the subspecies indicus in the waters off of the Middle East and in the Indian Ocean, and the subspecies mesonauta in the eastern portions of both the Atlantic and the Pacific Oceans and in the Caribbean. It was one of the many species described by Carl Linnaeus in his 1758 10th edition of Systema Naturae. Nesting takes place in loose colonies, as they nest a scrape found on a cliff face that is easy to take off from. A single egg is laid and is incubated by both sexes for about six weeks. Whether the egg hatches or not can be influenced by pollution and weather, although the latter has a minimal effect on whether a chick fledges or not. After a chick fledges, the parents will usually stop visiting the nest and the chick will leave. Birds of all ages feed on fish and squid, catching them by diving from the air into the water. However, the red-billed tropicbird sometimes follows surface-feeding predators. The predators will drive the prey to the surface, which are then seized by the tropicbird. In some areas, introduced black and brown rats raid nests for eggs and young. Cats also threaten the red-billed tropicbird. This bird is considered to be a least-concern species according to the International Union for Conservation of Nature (IUCN), though populations are thought to be declining. In some places, such as Brazil and Mexico, this bird is considered to be threatened.

Conservation

Least Concern

IUCN LC; DNER VU

Global IUCN
LC
Puerto Rico DNER
VU
Federal ESA
No current listing in source crosswalk
Critical habitat
Not identified in source crosswalk

Natural history

How it lives

Habitat
Sea cliffs; offshore cays; pelagic waters
Elevation
0–0 m
Nest
Crevice; Scrape · Ground
Clutch
1–1 eggs
Social behavior
Colonial

Keep exploring

This bird belongs to 9 paths through the atlas.

Evidence trail

Sources, media & further reading

Research note: Commonwealth VU in cited 2026 compilation