View source for Abbott's booby

{{Short description|Species of bird}}
{{Use dmy dates|date=May 2022}}
{{Speciesbox
| image              = Abbott's Booby.jpg
| image_caption      = 
| status             = EN
| status_system      = IUCN3.1
| status_ref         = <ref name=IUCN>{{cite iucn |author1=BirdLife International |date=2019 |title=''Papasula abbotti'' |volume=2019 |page=e.T22696649A152726109 |doi=10.2305/IUCN.UK.2019-3.RLTS.T22696649A152726109.en |access-date=6 September 2021}}</ref>
| status2 = CITES_A1 
 | status2_system = CITES 
 | status2_ref = <ref>{{Cite web|title=Appendices {{!}} CITES|url=https://cites.org/eng/app/appendices.php|access-date=2022-01-14|website=cites.org|archive-date=3 February 2007|archive-url=https://web.archive.org/web/20070203100154/http://www.cites.org/eng/app/appendices.shtml|url-status=live}}</ref>
| genus              = Papasula
| parent_authority   = [[Storrs Olson|Olson]] & [[Ken Warheit|Warheit]], 1988
| species            = abbotti
| authority          = ([[Robert Ridgway|Ridgway]], 1893)
| synonyms           = ''Sula abbotti'' ([[Robert Ridgway|Ridgway]], 1893)<ref name="Environment"/>
| range_map          = ChristmasEilandLocatie.png
| range_map_caption  = [[Christmas Island]] in green
}}

'''Abbott's booby''' ('''''Papasula abbotti''''') is an endangered [[seabird]] of the [[Sulidae|sulid]] family, which includes [[gannet]]s and [[Booby|boobies]]. It is a large booby 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 [[upwelling]]s, 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 [[Rainforest#Emergent layer|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 ant]]s, which decrease habitat quality. Minimal habitat declines have a significant effect on the bird population. All nesting areas have been included in a [[Christmas Island National Park|national park]].

==Taxonomy==
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 Islands|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, antedating the split between gannets and other boobies.<ref name="Environment">{{cite web|url=http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=59297 |title=Papasula abbotti&nbsp;– Abbott's Booby |publisher=Australian Government Department of Sustainability, Environment, Water, Population and Communities |access-date=30 March 2012}}</ref> 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.<ref>{{cite journal|author1=Friesen V.L. |author2=Anderson D.J. |year=1997|title=Phylogeny and Evolution of the Sulidae (Aves: Pelecaniformes): A Test of Alternative Modes of Speciation|journal= Molecular Phylogenetics and Evolution|volume=7|issue=2|pages=252–60|doi=10.1006/mpev.1996.0397|pmid=9126567|bibcode=1997MolPE...7..252F }}</ref> 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.<ref>{{cite journal|author1=Patterson, S.A. |author2=Morris-pocock, J.A. |author3=Friesen, V.L. |year=2011|title=A multilocus phylogeny of the Sulidae (Aves: Pelecaniformes)|journal= Molecular Phylogenetics and Evolution|volume=58|issue=2|pages=181–91|doi=10.1016/j.ympev.2010.11.021 |pmid=21144905|bibcode=2011MolPE..58..181P }}</ref> A [[subfossil]] subspecies from the [[Mascarene Islands]] of [[Mauritius]] and [[Rodrigues]] was named '' P. a. nelsoni'' in 2023.<ref name="Subfossil">{{cite journal |last1=Hume |first1=Julian P. |title=A new fossil subspecies of booby (Aves, Sulidae: ''Papasula'') from Mauritius and Rodrigues, Mascarene Islands, with notes on P. abbotti from Assumption Island |journal=Zootaxa |date=2023 |volume=5270 |issue=3 |pages=507–536 |doi=10.11646/zootaxa.5270.3.5 |pmid=37518153 |s2cid=258282986 |url=https://www.mapress.com/zt/article/view/zootaxa.5270.3.5 |issn=1175-5334 |access-date=6 May 2023 |archive-date=27 May 2024 |archive-url=https://web.archive.org/web/20240527112708/https://www.mapress.com/zt/article/view/zootaxa.5270.3.5 |url-status=live |url-access=subscription }}</ref>

The subspecies are:

* P. a. abotti (Christmas island booby)
* P. a. nelsoni (Mascarene booby)

==Description==
Abbott's booby is the largest of all booby species, and is adapted to long-distance flight.<ref name="ABCAbbotts"/> Individuals can reach {{convert|80|cm|in|abbr=on}} from beak to tail,<ref name="Perrins"/> and weigh about {{convert|1.5|kg|lb|abbr=on}}. 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.{{sfn|Marchant|Higgins|1990|p=791}} 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.<ref name="Environment"/> Chicks have white down and a cape of black scapular feathers.<ref name="Perrins"/>

Juvenile birds have plumage similar to adults, unlike other species of boobies.{{sfn|Marchant|Higgins|1990|p=791}}

==Distribution and habitat==
[[File:Papasula abbotti 408872264.jpg|thumb|On Christmas Island]]
Abbott's booby is the only booby restricted to a single location,<ref name="Perrins">{{cite encyclopaedia|title=Gannets and Boobies |encyclopedia=The New Encyclopedia of Birds |last=Nelson |first=J. Bryian |editor-last=Perrins |editor-first=Christopher |pages=83, 85–87 |publisher=Oxford University Press |year=2004 |isbn=0-19-852506-0}}</ref> although its former distribution covered much of the Indian and Pacific Oceans.<ref name=IUCN/> 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 (island)|Rota]] in the Pacific Ocean,<ref>{{cite journal |journal=Bulletin of the British Ornithologists' Club |title=An Abbott's Booby ''Papasula abbotti'' on Rota, Mariana Islands: first historical record for the Pacific Ocean |volume=129 |issue=2 |pages=87–91 |first1=H. Douglas |last1=Pratt |first2=Michael L. P. |last2=Retter |first3=Douglas |last3=Chapman |first4=W. Michael |last4=Ord |first5=Paul |last5=Pisano |year=2009 |url=http://boc-online.org/bulletins/downloads/Papasula%20abbotti%20in%20North%20Pacific%20Pratt%20et%20al.pdf |access-date=17 September 2014 |archive-date=11 April 2016 |archive-url=https://web.archive.org/web/20160411174658/http://www.boc-online.org/bulletins/downloads/Papasula%20abbotti%20in%20North%20Pacific%20Pratt%20et%20al.pdf |url-status=live }}</ref> and the same individual has been seen off-and-on in the [[red-footed booby]] colony there through at least 2024.{{citation needed|date=September 2024}}

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.<ref name="ABCAbbotts"/> 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 [[Rainforest#Emergent layer|emergent]] ''[[Tristiropsis acutangula]]'' trees are sometimes used. Due to the [[trade wind]]s flowing south-east from April to November, trees that can be approached from the northwest are favoured.<ref name="Environment"/>

Its foraging range usually reaches {{convert|40|-|100|km|mi|0|abbr=on}} 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.<ref name=IUCN/>

==Population==
The Abbott's booby population is the best documented, and smallest, of all sulid populations.<ref name="Perrins"/> It was first assessed in 1967,<ref name="Environment"/> resulting in an estimate of 2,300 breeding pairs. By 1983, the number of breeding pairs had declined to 1,900. The most comprehensive survey was made in 1991, and included new breeding sites that were unknown in previous surveys. It brought the estimate of breeding pairs up to 2,500, with the total number of mature individuals being placed at 6,000. A helicopter survey in 2002 noted 1,500 nest sites. The population was stable from 1991 to 2002.<ref name=IUCN/>

The population size is estimated to decrease more than 80% over the next three generations, or 120 years.<ref name="Outline">{{cite web|url=http://www.environment.gov.au/biodiversity/threatened/publications/action/birds2000/pubs/abbotts-booby.pdf |title=Recovery Outline Abbott's Booby |publisher=Australian Government Department of Sustainability, Environment, Water, Population and Communities |access-date=30 March 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120228222800/http://www.environment.gov.au/biodiversity/threatened/publications/action/birds2000/pubs/abbotts-booby.pdf |archive-date=28 February 2012 }}</ref> The current decline is attributed to a low recruitment rate and the negative effects of wind turbulence on a breeding population. Due to its small population, limited habitat, low fecundity, and limited distribution, Abbott's booby is at high risk of extinction if further habitat disturbance occurs.<ref name="ABCConservation">{{cite web |url=http://www.abc.net.au/nature/island/ep2/about5.htm |title=Conservation |publisher=Australian Broadcasting Corporation |access-date=29 March 2012 |archive-url=https://web.archive.org/web/20140103035926/http://www.abc.net.au/nature/island/ep2/about5.htm |archive-date=3 January 2014 |url-status=dead }}</ref>

==Ecology==
[[File:Flying Abbott's booby.jpg|thumb|In flight]]
Individuals are solitary, long-distance travellers that can range thousands of kilometres from Christmas Island. They are very vocal, with a wide range of calls. Due to their size, they require a large clear space to take off. So, they nest near the tops of trees. If an individual falls to the forest floor, it will starve unless it can climb high enough to be able to catch the wind and take off.<ref name="ABCAbbotts"/> Adults rarely fight owing to the risk of falling.<ref name="Perrins"/> Fledglings must succeed in their first attempt at flight; unsuccessful attempts rarely result in the fledgling's survival.<ref name="ABCAbbotts"/>

Adults forage at sea from October to April, although they return if they have a chick that is dependent on them.<ref name="ABCAbbotts"/> They forage in offshore waters,<ref name="Perrins"/> eating fish and squid. No feeding patterns are known,<ref name=IUCN/> although they are thought to forage in an ocean [[upwelling]] off [[Java]], {{convert|300|km|mi|0|abbr=on}} northwest of Christmas Island.<ref name="ABCAbbotts"/> Chicks are fed through complete regurgitation for the first two weeks, then incomplete regurgitation. Both parents feed the young.{{sfn|Marchant|Higgins|1990|p=795}}<!--cites 2 previous sentences -->

===Breeding===
Courtship takes the form of a face-to-face display. Partners mate for life, and maintain the same nest site throughout their lives.<ref name="Perrins"/> Nests are made near the top of rainforest trees, {{convert|10|-|40|m|ft|0|abbr=on}} off the ground,<ref name="Environment"/> usually at elevations of {{convert|150|m|ft|0|abbr=on}} or higher.<ref name=IUCN/> Breeding cycles last 15–18 months, and only one [[Bird egg|egg]] is laid during each cycle. Successful pairs can nest once every two years, but often take rest years between attempts to raise a chick. These rest years are taken even if the couple is unsuccessful in raising their chick.<ref name=IUCN/> Most pairs only breed once every three years.<ref name="ABCAbbotts"/>

Mating usually takes place in April, and eggs are laid between April and July.<ref name="ABCAbbotts">{{cite web |url=http://www.abc.net.au/nature/island/ep2/locals/1b.htm |title=Abbott's Booby (''Papsula abbotti'') |publisher=Australian Broadcasting Corporation |access-date=29 March 2012 |archive-url=https://web.archive.org/web/20130619034116/http://www.abc.net.au/nature/island/ep2/locals/1b.htm |archive-date=19 June 2013 |url-status=dead }}</ref> Eggs are equal to 8% of the female's body weight. They are incubated under the webbed feet of the parents, which become vascularised and warm.<ref name="Perrins"/> Incubation is undertaken by both parents, which take shifts of up to two days. Eggs are incubated for about 56 days,<ref name="ABCAbbotts"/> which is 30 days longer than in other sulids.<ref name="Environment"/> Chicks hatch from June to November, after the eggs are incubated around 56 days.<ref name="ABCAbbotts"/> They take 170 days to fully fledge, and an additional 200 days to become fully independent.<ref name="ABCAbbotts"/> Most chicks make their first flight in December or January.<ref name=HANZAB1>Marchant, S.; & Higgins, P.J. (Eds). (1990). ''[[Handbook of Australian, New Zealand and Antarctic Birds]]. Volume 1: Ratites to Ducks''. Oxford University Press: Melbourne. {{ISBN|0-19-553068-3}}</ref><ref name=Nelson1978>[[Joseph Bryan Nelson|Nelson, J. Bryan]]. (1978). ''The Sulidae. Gannets and Boobies''. Oxford University Press: Oxford. {{ISBN|0-19-714104-8}}</ref> Fledglings reach maturity around eight years of age, and can live up to 40 years.<ref name=IUCN/>

==Threats and conservation==
[[File:Jungle exploration.jpg|thumb|Conservation work for the Abbott's Booby on Christmas Island. A drone is launched from the gaps within the canopies to explore for potential nesting sites. The birds can be detected through their predominantly white color against green foliage.]]
Even a minimal decline in habitat quality can have a significant impact on these birds. During 1965–1987, phosphate mining destroyed one-third of the Abbott's booby's nesting habitat. Degeneration has continued, with the health of individual trees decreasing.<ref name=IUCN/> Clearings left over from logging have increased wind in the canopy, generating turbulence up to {{convert|300|m|ft|0|abbr=on}} downwind of the clearings. This causes lower breeding success due to chicks being dislodged and not surviving their first flight. Adult survival is also reduced due to increased risk of them falling to the ground when landing.<ref name="ABCConservation"/> This affects 36% of the current population.<ref name="Environment"/>

Introduced plants are foiling habitat rehabilitation in abandoned mining sites and pose a risk if they invade primary forest. Continued mining remains an issue, with mature secondary forest cleared for mining in 2007. A request to mine in what is currently 250&nbsp;half of forest was turned down in 2007, but is under appeal.<ref name=IUCN/> Christmas Island Phosphates Pty Ltd. may not clear primary forest, and requires a permit to clear regrowth.<ref name=IUCN/>

[[Christmas Island National Park]] includes all known Abbott's booby nest sites.<ref name="ABCConservation"/> It was created in 1980 and was subsequently expanded to cover 60% of the island.<ref name=IUCN/> The population was monitored from 1982 to 1993, and in 1984, 20% of mined areas next to nesting sites had been replanted.<ref name=IUCN/> The Environment Australia Abbott's Booby Recovery Plan aims to regenerate forests and help prevent further decline in the species. Forest rehabilitation has now been attempted in about 30% of abandoned mining areas, with a focus on areas close to primary forest where new growth could act as a wind break. Most of the planted trees are [[foundation species]], with non-native species being used if they do not invade the environment. Part of the forest regeneration project is financed by the phosphate mining company as part of their lease agreement.<ref name="ABCConservation"/>

[[File:Anoplolepis gracilipes 2.jpg|thumb|alt=Two yellow ants|[[Yellow crazy ant]]s]]
An invasion of the [[yellow crazy ant]] poses continued risk for the booby population. Yellow crazy ants formed [[supercolony|supercolonies]] in the 1990s and spread throughout 28% of the island's forest. Starting in 2000, efforts to control it eliminated it from 2,800&nbsp;ha of forest, resulting in a 95% reduction of its range. The range was 300&nbsp;ha in 2005, at much lower densities than originally, although it has slightly recovered since then. The ants could prey on nestlings and cause nest abandonment, although this has not been observed. They do, however, disrupt the ecosystem by killing [[Christmas Island red crab|red crab]]s, and farm [[scale insect]]s that damage the trees where the boobies nest.<ref name=IUCN/>

[[Overfishing]] and [[marine pollution]] pose additional problems for the population. The birds may be directly hunted<ref name=IUCN/> or caught as bycatch in [[longline fishing]],<ref name="Outline"/> as they may come into contact with Indonesian and Taiwanese fisheries. This has not been documented.<ref name=IUCN/>

Plans for a satellite launch pad to be built on the island have been discussed, but are not currently being put into action.<ref name=IUCN/>

In 1988, a cyclone destroyed a third of all nests and fledglings. Climate change resulting in increased sea surface temperatures, changes in rainfall patterns, and changes in the [[El Niño Southern Oscillation]] may further damage the population due to changing weather patterns.<ref name=IUCN/> The increase in sea temperatures reduces breeding success, as the best feeding is found in cold water caused by nutrient-rich upwellings.<ref name="Environment"/>

Abbott's booby is listed under [[CITES]] Appendix I, and is classified as endangered in the [[IUCN Redlist]].<ref name=IUCN/> It is also classified as endangered under the Australian [[Environment Protection and Biodiversity Conservation Act 1999]].<ref name="Environment"/> Many Abbott's boobies are in the National Park, so their nests are monitored.

==References==
{{Reflist}}

==Further reading==
* {{cite book |editor1-last=Marchant |editor1-first=S. |editor2-last=Higgins |editor2-first=P.G. |year=1990 |chapter=''Sula dactylatra'' Masked booby |title=Handbook of Australian, New Zealand & Antarctic Birds. Volume 1: Ratites to ducks; Part B, Australian pelican to ducks |place=Melbourne, Victoria |publisher=Oxford University Press |isbn=978-0-19-553068-1 |pages=763–72 }}

==External links==
{{Wikispecies|Papasula abbotti}}
{{Commons category}}
* [https://web.archive.org/web/20120228222800/http://www.environment.gov.au/biodiversity/threatened/publications/action/birds2000/pubs/abbotts-booby.pdf Australian Government's 2000 Recovery Outline]
* [https://web.archive.org/web/20120322144547/http://www.environment.gov.au/biodiversity/threatened/publications/recovery/abbotts-booby/pubs/p-abbotti.pdf National recovery plan]

{{Suliformes}}
{{Suliformes Genera|S.|state=collapsed}}
{{Taxonbar|from=Q839854}}
{{Authority control}}

[[Category:Sulidae]]
[[Category:Boobies]]
[[Category:Birds of Christmas Island]]
[[Category:Birds described in 1893]]
[[Category:Endangered fauna of Australia]]
[[Category:Endangered fauna of Oceania]]
[[Category:Taxa named by Robert Ridgway]]