Phaethon aethereus

Medium-sized white seabird, the central tail feathers are extended in a linear shape, the adult bird has black spots before and behind the eyes, forming a black eyebrow, the outer sides of the primary flight feathers are black, there are two black oblique spots on the wings, but there are multiple stripes on the white back The black striped spots distinguish it from other grebes. The tail feathers of the immature bird are not extended, with black dot-like spots at the ends, and the upper body has prominent, thick black horizontal spots. The iris is dark brown, the beak is red, the tarsometatarsus is yellow, and the legs are black.

Distributed in tropical and subtropical parts of the Pacific and Indian Oceans, from Oceania in the south to Japan in the north, Taiwan Island, Anguilla, Antigua and Barbuda, Bahamas, Barbados, Bonaire, Sint Eustatius and Saba, Brazil, Cape Verde, Cayman Islands, Chile, China, Colombia, Cuba, Curaçao, Djibouti, Dominica, Dominican Republic, Ecuador (Galapagos Islands), Egypt, El Salvador, Eritrea, French Guiana, Grenada, Guadeloupe, Guinea, Guinea-Bissau, Haiti, Iran (Islamic Republic of), Maldives, Mauritania, Mexico, Montserrat, Oman, Pakistan, Panama, Peru, Portugal, Puerto Rico, Qatar, Saint Helena, Ascension Island, Tristan da Cunha, Saint Kitts and Nevis, Saint Lucia, Saint Martin (French) , Saint Vincent and the Grenadines, Saudi Arabia, Senegal, Sint Maarten (Dutch), Somalia, Trinidad and Tobago, Turks and Caicos Islands, United Arab Emirates, Venezuela (Bolivarian Republic of), Virgin Islands, Yemen, etc., mainly living on cliffs of oceanic islands.

 Distributed in tropical and subtropical parts of the Pacific and Indian Oceans, from Oceania in the south to Japan in the north, Taiwan Island, Anguilla, Antigua and Barbuda, Bahamas, Barbados, Bonaire, Sint Eustatius and Saba, Brazil, Cape Verde, Cayman Islands, Chile, China, Colombia, Cuba, Curaçao, Djibouti, Dominica, Dominican Republic, Ecuador (Galapagos Islands), Egypt, El Salvador, Eritrea, French Guiana, Grenada, Guadeloupe, Guinea, Guinea-Bissau, Haiti, Iran (Islamic Republic of), Maldives, Mauritania, Mexico, Montserrat, Oman, Pakistan, Panama, Peru, Portugal, Puerto Rico, Qatar, Saint Helena, Ascension Island, Tristan da Cunha, Saint Kitts and Nevis, Saint Lucia, Saint Martin (French) , St. Vincent and the Grenadines, Saudi Arabia, Senegal, Sint Maarten (Dutch), Somalia, Trinidad and Tobago, Turks and Caicos Islands, United Arab Emirates, Venezuela (Bolivarian Republic), Virgin Islands, Yemen, etc., mainly living on cliffs of oceanic islands.

Migrant bird: Angola, Bermuda, Costa Rica, French Polynesia, Gabon, Gambia, India, Israel, Jamaica, Jordan, Kuwait, Madagascar, Malaysia, Mauritania, Myanmar, Netherlands, Seychelles, South Africa, Spain (Canary Islands), Sri Lanka, Sudan, United Kingdom, United States (Hawaii Island), Vietnam.

Origin uncertain: Bahrain, Belize, Benin, Cameroon, Democratic Republic of Congo, Cote d'Ivoire, Equatorial Guinea, Ghana, Guatemala, Guyana, Honduras, Iraq, Liberia, Nicaragua, Nigeria, Sao Tome and Principe, Suriname, Togo, Western Sahara.

This tropical bird undergoes an annual molt, using a complex basic strategy. This molt is completed before courtship and lasts 19 to 29 weeks, most of which are completed within 24 weeks. The chicks grow into adult plumage at two to three years of age.

The red-billed thrush usually only sings near breeding colonies, where it joins groups of 2 to 20 adults, circling over the sea and making a loud, piercing kreeeee-kreeeee-kri-kri-kri-kr call. If startled in the nest, the chicks will make a loud, shrill call that can be quite piercing and last for a while.

The Red-billed Pied Piper is monogamous and usually nests in loose colonies on isolated cliff faces. It uses a simple scrape nest located in a location from which it can easily take off. Age at first breeding is usually five years, but this age is variable; a three-year-old tropical bird has been seen breeding. Breeding varies by region, with breeding occurring year-round or seasonally. For example, on islands in the California Current, breeding begins in November or December, while in the Galapagos Islands it occurs year-round. Reproduction is influenced by food availability, with increased food generally resulting in increased reproduction. Individual breeding cycles are nine to twelve months. A breeding bird will usually return to the mate and nesting location of the previous breeding cycle.

Courtship and pairing usually last three to five weeks, during which time the bird performs aerial courtship displays to potential mates. Courtship displays involve gliding through the air with intermittent rapid flapping of the wings. In one display, a pair of birds will glide together for 100–300 m (330–980 ft), with one bird about 30 cm (12 in) above the other. The bird on top bends its wings downward, while the bird below lifts its wings upward so that they are almost touching. The two birds descend to about 6 m (20 ft) above the sea before separating.

Fights between two or more pairs sometimes occur over nesting sites until the original nest owner claims ownership. Red-billed trout are aggressive in their nesting sites, fighting with other birds and driving away species such as gulls, petrels, and white-tailed tropicbirds. If they fail to destroy the eggs of white-tailed tropicbirds, they have been recorded taking over their nests and raising their chicks. In Hawaii, stray red-billed tropicbirds are thought to be associated with the loss of eggs from red-tailed tropicbird nests.

This tropicbird typically lays a single white to lavender egg with reddish-brown spots. The eggs are typically 45 by 60 millimeters (1.8 by 2.4 in) in size and weigh about 67 grams (2.4 ounces), about 10% of the adult female's body weight. Incubation is carried out by both sexes for 42 to 46 days. If an egg does not survive the first few days in the nest, the female will usually lay a replacement egg. The chicks usually leave the nest about 10 to 15 weeks after hatching, although most leave after about 80 to 90 days. The maximum weight of a chick is usually about 725 grams (1.6 lb), but in years with warmer than average temperatures, this may drop to about 600 grams (1.3 lb).

The chicks are helpless and unable to move at birth (nest-dwelling and semi-altricial), and remain closely nurtured by their parents until they are 3 to 5 days old and can regulate their own body temperature. The chicks grow their first feathers, the shoulder feathers, at 13 to 15 days old, followed by primary flight feathers at 24 to 27 days, and tail feathers at 30 to 35 days, and are covered in gray down. This down is shed in about 40 to 50 days. Juveniles lack the tail ribbon. Juveniles look similar to adults, with a mostly white head. The stripe above the eye in juveniles usually joins at the nape. The tail feathers usually have black tips or sub-tips, and lack the tail ribbon characteristic of adults. Occasionally, juveniles have black markings on the flanks and undertail coverts. Fully grown in 55 days. Parents pay more attention to the chicks between days 30 and 60; this may be related to the chicks' greater need for food during this time. Partially digested food is regurgitated and fed to the young, while older birds are fed solid food. Normal parental care of the chicks can continue until about day 70, after which parental care rapidly decreases. Chicks are no longer cared for after leaving the nest, with only about one in seven chicks still being fed after day 80, and almost no chicks being visited after about day 90. The chicks leave the nest after they have fledged, though a few remain after about 100 days. Adults feed their chicks for 67-91 days.

The Red-billed Tropicbird can be distinguished from other tropical birds by its red bill and white tail ribbon. The slightly smaller Red-tailed Tropicbird has a red rather than white tail ribbon, while the White-tailed Tropicbird can be distinguished by its smaller size, black stripes on the upper wing coverts, and yellow-orange bill. The chicks of the Red-billed Tropicbird have more horizontal stripes on their upper parts than the chicks of other species. In flight, the Orange-billed Crested Tern can be confused with an adult Red-billed Tropicbird, but can be distinguished by its less direct flight pattern and lack of a tail ribbon.

This tropical bird undergoes an annual molt, using a complex basic strategy. This molt is completed before courtship, lasting 19 to 29 weeks, with most completed within 24 weeks. The chicks grow adult plumage at two to three years of age. Sexual maturity is achieved at 2-5 years of age, and they return to the breeding grounds to nest and court.