Sula leucogaster 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Suliformes Sulidae

Scientific Name: Sula leucogaster
Species Authority: (Boddaert, 1783)
Common Name(s):
English Brown Booby
French Fou brun
Taxonomic Source(s): Turbott, E.G. 1990. Checklist of the birds of New Zealand. Ornithological Society of New Zealand, Wellington.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2015
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Facilitator/Compiler(s): Butchart, S., Calvert, R. & Ekstrom, J.
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Previously published Red List assessments:
2009 Least Concern (LC)
2008 Least Concern (LC)
2004 Least Concern (LC)
2000 Lower Risk/least concern (LR/lc)
1994 Lower Risk/least concern (LR/lc)
1988 Lower Risk/least concern (LR/lc)

Geographic Range [top]

Range Description: The Brown Booby can be found throughout the pantropical oceans with few exceptions. Breeding sites include the Carribean, the Atlantic coasts of Brazil and Africa, oceanic islands off Madagascar, the Red Sea, northern Australia, many oceanic islands in the western and central Pacific, as well as off the coast of Mexico and Peru1.
Countries occurrence:
American Samoa (American Samoa); Anguilla; Antigua and Barbuda; Argentina; Aruba; Australia; Bahamas; Barbados; Belize; Bonaire, Sint Eustatius and Saba (Saba, Sint Eustatius); Brazil; British Indian Ocean Territory; Brunei Darussalam; Canada; Cape Verde; Cayman Islands; China; Christmas Island; Cocos (Keeling) Islands; Colombia; Comoros; Cook Islands; Costa Rica; Cuba; Curaçao; Djibouti; Dominica; Dominican Republic; Ecuador; Egypt; El Salvador; Equatorial Guinea; Eritrea; Fiji; French Guiana; French Polynesia; Gabon; Grenada; Guadeloupe; Guam; Guatemala; Guinea; Guinea-Bissau; Guyana; Haiti; Honduras; India; Indonesia; Israel; Jamaica; Japan; Jordan; Kenya; Kiribati; Liberia; Madagascar; Malaysia; Maldives; Marshall Islands; Martinique; Mauritania; Mayotte; Mexico; Micronesia, Federated States of ; Montserrat; Myanmar; Nauru; New Caledonia; Nicaragua; Nigeria; Northern Mariana Islands; Oman; Palau; Panama; Philippines; Puerto Rico; Saint Helena, Ascension and Tristan da Cunha; Saint Kitts and Nevis; Saint Lucia; Saint Martin (French part); Saint Vincent and the Grenadines; Samoa; Sao Tomé and Principe; Saudi Arabia; Seychelles; Singapore; Sint Maarten (Dutch part); Solomon Islands; Somalia; Sri Lanka; Sudan; Suriname; Taiwan, Province of China; Thailand; Timor-Leste; Tonga; Trinidad and Tobago; Turks and Caicos Islands; United States (Hawaiian Is. - Vagrant); United States Minor Outlying Islands; Vanuatu; Venezuela, Bolivarian Republic of; Viet Nam; Virgin Islands, British; Virgin Islands, U.S.; Wallis and Futuna; Yemen
Benin; Bermuda; Gambia; Ghana; Hong Kong; Morocco; Mozambique; New Zealand; Portugal; Senegal; Sierra Leone; South Africa; Spain; United Arab Emirates; Uruguay
Present - origin uncertain:
Cambodia; Cameroon; Chile; Côte d'Ivoire; French Southern Territories; Korea, Democratic People's Republic of; Korea, Republic of; Mauritius; Norfolk Island; Pakistan; Papua New Guinea; Pitcairn; Tanzania, United Republic of; Togo; Tokelau; Tuvalu; Western Sahara
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 26600000
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Continuing decline in number of locations: Unknown
Extreme fluctuations in the number of locations: No
Upper elevation limit (metres): 100
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The global population is estimated to number > c.200,000 individuals (del Hoyo et al. 1992), while national population sizes have been estimated at c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in Taiwan and c.10,000-100,000 breeding pairs, c.1,000-10,000 individuals on migration and c.1,000-10,000 wintering individuals in Japan (Brazil 2009).

Trend Justification:  The population is suspected to be in decline owing to disturbance and unsustainable levels of exploitation.
Current Population Trend: Decreasing
Additional data:
Continuing decline of mature individuals: Unknown
Extreme fluctuations: No Population severely fragmented: No
Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No

Habitat and Ecology [top]

Habitat and Ecology: This species is strictly marine, generally feeding on inshore waters. Its diet is comprised mainly of flying-fish and squid, but also some halfbeak (Hemiramphu), mullet (Mugil) and anchovy (Engraulis). Prey is usually caught by plunge-diving and it can also snatch prey off the surface of water. Kleptoparasitism has been observed, mostly by females. Breeding is seasonal in some reas by elsewhere it breeds opportunistically or more or less continuously. Nests are usually built on the ground in the midst of vegetation on rocky islands or coral atolls. Individuals form colonies that are usually smaller than other Sula species (del Hoyo et al. 1992).
Systems: Terrestrial; Marine
Continuing decline in area, extent and/or quality of habitat: Unknown
Generation Length (years): 17.3
Movement patterns: Not a Migrant
Congregatory: Congregatory (and dispersive)

Citation: BirdLife International. 2015. Sula leucogaster. The IUCN Red List of Threatened Species 2015: e.T22696698A85098448. . Downloaded on 26 November 2015.
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