Abbott's Booby

识别特征

Abbott's booby is the largest of all booby species, and is adapted to long-distance flight. Individuals can reach 80 cm (31 in) from beak to tail, and weigh about 1.5 kg (3.3 lb). It is distinguished from other sulids in the region by its black and white plumage; the only other bird with similar coloration and shape is the masked booby, which has an all-white body with black wings only. They have an off-white plumage, which contrasts with black eye patches, black wings and tails, and black flank marks. Their feet are blue and webbed, with black outer ends. Males have pale grey bills with a black tip, whereas females have pink bills with a black tip. Chicks have white down and a cape of black scapular feathers.<p>Juvenile birds have plumage similar to adults, unlike other species of boobies.

分类信息

The first specimen was collected from Assumption Island in 1892 by American naturalist William Louis Abbott, northwest of Madagascar, although debate exists as to whether he actually collected it from the nearby Glorioso Island. It was described by Robert Ridgway in 1893. In 1988, it was placed in its own genus by Olson &amp; Warheit 1988. The basal characters present in this species suggest it may be an early branch of the sulid family, antedating the split between gannets and other boobies. This was reinforced by analysis of the mitochondrial cytochrome b gene in 1997, which indicated Abbott's booby was an early offshoot of the gannets rather than the other boobies. However, 2011 study of multiple genes found it to be basal to all other gannets and boobies, and likely to have diverged from them around 22 million years ago. A subfossil subspecies from the Mascarene Islands of Mauritius and Rodrigues was named P. a. nelsoni in 2023.

学名

Papasula abbotti

命名信息

(Ridgway, 1893)

目

Suliformes

科

Sulidae

属

Papasula

分布与栖息地

Abbott's booby is the only booby restricted to a single location, although its former distribution covered much of the Indian and Pacific Oceans. Fossil evidence indicates its former presence in the South Pacific, and eyewitness reports of it formerly breeding on the Mascarene Islands. In April 2007, an individual of this species was photographed at a booby colony on Rota in the Pacific Ocean, and the same individual has been seen off-and-on in the red-footed booby colony there through at least 2024.<p>It breeds in tall trees in the plateau forests of the central and western areas of Christmas Island, and in the upper terrace forests of the north coast. Nest distribution is patchy, based on topography, with the majority of nests in trees on uneven terrain. Nests are usually built on Syzygium nervosum and Planchonella nitida trees, although emergent Tristiropsis acutangula trees are sometimes used. Due to the trade winds flowing south-east from April to November, trees that can be approached from the northwest are favoured.<p>Its foraging range usually reaches 40–100 km (25–62 mi) from Christmas Island, although individuals are often seen in Indonesia and vagrants reach as far as mainland Australia. A single female was recently observed on Rota, northeast of Guam in the Pacific, and some records from the Banda Sea indicate either an even larger range or unknown breeding colonies.

繁殖区

IO : Christmas I. (s of w Java); formerly Assumption (Aldabra group, sw Seychelles), Mauritius and Rodrigues (c, e Mascarenes, sw Indian Ocean); subfossil remains from Solomon Is., Vanuatu, and Marquesas (ne Polynesia)

非繁殖区

to near Java, s, c Moluccas and sw of New Guinea

迁徙

Complete migrants

行为

Migration pattern: Complete migrants.

保护状况

Population trend: stable.

种群趋势

stable