Nepedia
Back to Discover
Advanced Reader
🧬

Tropicbird

life science Maturity 5-7 Next article →

Tropicbirds are a unique family of tropical seabirds known as Phaethontidae. They are pelagic, which means they spend much of their lives on the open ocean. These birds are the only living members of their specific order, Phaethontiformes. They are easily recognized by their bright white plumage and very long central tail feathers.

Red-billed Tropicbird JCB
Red-billed Tropicbird JCB

Their large heads and short, thick necks give them a distinct appearance. Because they are so specialized for life at sea, they have developed very specific physical traits.

Physically, tropicbirds are built for life in the air and the water. They range in length from 76 cm to 102 cm. Their wingspans are also quite large, measuring between 94 cm and 112 cm. They possess large, powerful bills that are slightly decurved, or curved downward. Their feet are totipalmate, meaning all four toes are connected by webbing.

However, their legs are positioned very far back on their bodies. This placement makes walking on land impossible. To move on the ground, they must push themselves forward using their feet.

There are currently three living species within the genus Phaethon. The red-billed tropicbird (Phaethon aethereus) lives in the tropical Atlantic, eastern Pacific, and Indian oceans. The red-tailed tropicbird (Phaethon rubricauda) inhabits the Indian Ocean and the western and central tropical Pacific. The white-tailed tropicbird (Phaethon lepturus) is widespread in tropical waters, except for the eastern Pacific.

White-tailed tropicbird (Phaethon lepturus)
White-tailed tropicbird (Phaethon lepturus)

Scientists believe the red-billed species split from the others about six million years ago. The split between the red-tailed and white-tailed species happened about four million years ago.

For a long time, scientists classified tropicbirds in the order Pelecaniformes. This group traditionally included pelicans, cormorants, shags, darters, gannets, boobies, and frigatebirds. However, new evidence has changed our understanding of their history. In 1995, Konstantin Mikhailov performed a microscopic analysis of eggshell structures. He discovered that tropicbird eggshells lacked the thick microglobular material found in other Pelecaniformes.

Red-billed Tropicbird JCB
Red-billed Tropicbird JCB

Later, a 2014 whole-genome analysis showed they are actually most closely related to the sunbittern and the kagu.

Feeding and survival in the open ocean require specific behaviors. Tropicbirds often hunt by hovering over the water and then performing a plunging-dive. They typically only dive into the surface layer of the ocean to catch prey. Their diet consists mostly of fish, particularly flying fish, and occasionally squid. Unlike frigatebirds, which often feed in large flocks, tropicbirds tend to avoid multi-species feeding groups. This solitary approach is part of their specialized pelagic lifestyle.

Courtship and nesting are also very distinct processes. During courtship, groups of 2 to 20 birds fly in large, vertical circles. They swing their long tail streamers from side to side to impress potential mates.

After mating, the female lays a single white egg with brown spots in a ground crevice. Both parents participate in incubation, which lasts between 40 and 46 days. The male brings food to the female while she sits on the egg. The chick hatches with grey down and remains in the nest for 12 to 13 weeks.

Young tropicbirds have a unique way of preparing for flight. Because they grow more slowly than nearshore birds, they accumulate fat deposits while young. This helps them survive when food is hard to find in the open ocean. Before they can fly, the chicks actually float on the ocean surface for several days. This period allows them to lose weight, making it easier for them to take to the air. This specialized development is an adaptation to their life in the vast, unpredictable sea.

590 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (3)
File:Red tailed tropic bird.jpg
Red tailed tropic bird.jpg
File:Red-billed Tropicbird JCB.jpg
Red-billed Tropicbird JCB.jpg
File:White-tailed tropicbird (Phaethon lepturus).jpg
White-tailed tropicbird (Phaethon lepturus).jpg
More to explore

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.