The red‑tailed tropicbird (Phaethon rubricauda) is a seabird belonging to the family Phaethontidae. It is one of three extant species of tropicbirds, the others being the white‑tailed tropicbird (Phaethon lepturus) and the red‑billed tropicbird (Phaethon aethereus).
Taxonomy and Nomenclature
- Kingdom: Animalia
- Phylum: Chordata
- Class: Aves
- Order: Phaethontiformes
- Family: Phaethontidae
- Genus: Phaethon
- Species: P. rubricauda
The species epithet “rubricauda” derives from Latin, with rubri meaning “red” and cauda meaning “tail,” referring to the bird’s distinctive crimson tail feathers.
Physical Description
- Size: Approximately 85–95 cm (33–37 in) in length, including the tail.
- Weight: 200–285 g (7.1–10.1 oz).
- Plumage: Predominantly white body with a black cap and a thin black facial mask extending from the beak to the eye. The tail feathers are long (up to 20 cm) and bright red, branching into three streamers.
- Bill: Black, slightly hooked at the tip.
- Wings: Long, narrow, and pointed, adapted for dynamic soaring over open ocean.
Distribution and Habitat
The red‑tailed tropicbird has a pantropical distribution across the Indian and Pacific Oceans. It breeds on remote oceanic islands and atolls, including:
- The Hawaiian Islands (e.g., Nihoa, Necker Island)
- The Galápagos Islands
- Easter Island
- Several islands of French Polynesia, the Marshall Islands, and the Seychelles
Outside the breeding season, the species is pelagic, spending most of its life over open water, often far from land.
Behavior and Ecology
- Feeding: Primarily piscivorous, catching fish and squid by plunge‑diving from a few meters above the water surface. Prey includes flying fish, scombrids, and small cephalopods.
- Reproduction: Colonial nester; nests are simple depressions scraped into the ground, often among vegetation or rock crevices. The clutch consists of a single egg, which is incubated for about 45 days by both parents. Fledging occurs roughly 55 days after hatching.
- Vocalizations: Generally silent at sea; on breeding colonies, low, guttural croaks and soft rattles are used for communication.
Conservation Status
The International Union for Conservation of Nature (IUCN) classifies the red‑tailed tropicbird as Least Concern. Population trends are considered stable, although localized threats exist:
- Habitat disturbance from human activity on breeding islands (e.g., tourism, introduced predators).
- Potential impacts of climate change on oceanic food web dynamics.
Cultural Significance
The red‑tailed tropicbird appears on the coat of arms of the Republic of Kiribati and is featured in various Pacific island folklore, often symbolizing agility and freedom due to its aerial displays.
References
- BirdLife International species factsheet: Phaethon rubricauda
- "Handbook of the Birds of the World, Volume 1: Ostrich to Ducks" (del Hoyo et al., 1992)
- IUCN Red List entry for Phaethon rubricauda (2022)
