Papasula abbotti

Abbott's booby (Papasula abbotti) is an endangered seabird of the sulid family, which includes gannets and boobies. It is a large booby, smaller than gannets, and is placed within its own monotypic genus. It was first identified from a specimen collected by William Louis Abbott, who discovered it on Assumption Island in 1892. Abbott's booby breeds only in a few spots on the Australian territory of Christmas Island in the eastern Indian Ocean, although it formerly had a much wider range. It has white plumage with black markings, and is adapted for long-distance flight. It forages around Christmas Island, often around nutrient-rich oceanic upwellings, although individuals can travel for thousands of kilometres. Pairs mate for life and raise one chick every two or three years, nesting near the top of emergent trees in the rainforest canopy. The population is decreasing. Historically much of its former habitat was logged to make way for phosphate mining. Some logging continues, and the effects of the former logging continue to adversely affect the current population. Another threat has been caused by the introduction of yellow crazy ants, which decrease habitat quality. Minimal habitat declines have a significant effect on the bird population. All nesting areas have been included in a national park. The first specimen was collected from Assumption Island in 1892 by American naturalist William Louis Abbott, northwest of Madagascar, although there is debate on 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 & Warheit 1988. The basal characters present in this species suggest it may be an early branch of the sulid family, predating 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. 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. Juvenile birds have plumage similar to adults, unlike other species of booby. Abbott's booby is the only booby restricted to a single location, although its former distribution covered much of the Indian and Pacific Oceans. There is fossil evidence of 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 2011 (Pratt in press). 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 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.