Thalasseus bengalensis 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Charadriiformes Laridae

Scientific Name: Thalasseus bengalensis
Species Authority: (Lesson, 1831)
Common Name(s):
English Lesser Crested Tern, Lesser Crested-Tern
French Sterne voyageuse
Sterna bengalensis Lesson, 1831
Thalasseus bengalensis Christidis and Boles (2008)
Taxonomic Source(s): del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Lynx Edicions BirdLife International.
Taxonomic Notes: Thalasseus bengalensis (del Hoyo and Collar 2014) was previously placed in the genus Sterna.

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. & Malpas, L.
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). The population trend appears to be stable, and hence the species does not 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 Lesser Crested Tern breeds in subtropical coastal parts of the world mainly from the Red Sea across the Indian Ocean to the western Pacific, and Australia, with a significant population on the southern coast of the Mediterranean on two islands off the coast of Libya. Outside the breeding season it ranges on the north African coast (both Mediterranean and Atlantic), on much of the Indian Ocean nearby continents, and in the western Pacific north of Australia up to New Guinea and Vietnam1.

Countries occurrence:
Algeria; Australia; Bahrain; Bangladesh; British Indian Ocean Territory; Brunei Darussalam; China; Comoros; Djibouti; Egypt; Eritrea; Gambia; Guinea; Guinea-Bissau; India; Indonesia; Iran, Islamic Republic of; Iraq; Israel; Italy; Kenya; Kuwait; Libya; Madagascar; Malaysia; Maldives; Mauritania; Mauritius; Mayotte; Morocco; Mozambique; Myanmar; Oman; Pakistan; Papua New Guinea; Qatar; Saudi Arabia; Seychelles; Singapore; Somalia; South Africa; Spain; Sri Lanka; Sudan; Tanzania, United Republic of; Thailand; Timor-Leste; Tunisia; United Arab Emirates; Yemen
Regionally extinct:
Austria; Cambodia; France; Ghana; Gibraltar; Greece; Jordan; Netherlands; Palestinian Territory, Occupied; Senegal; Switzerland; Turkey; Uganda; United Kingdom
Present - origin uncertain:
French Southern Territories; Philippines; Réunion; Solomon Islands; Viet Nam; Western Sahara
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 1820000
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
Range Map: Click here to open the map viewer and explore range.

Population [top]

Current Population Trend: Stable
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: Behaviour The details of this species's movements are poorly known although some breeding populations appear to be migratory (del Hoyo et al. 1996). The species breeds in large dense colonies of up to 20,000 pairs (del Hoyo et al. 1996) often with other species (del Hoyo et al. 1996). It is gregarious throughout the year, foraging in single- or mixed-species flocks up to 400 individuals (del Hoyo et al. 1996, Snow and Perrins 1998). Habitat The species inhabits tropical and subtropical (del Hoyo et al. 1996) sandy and coral coasts and estuaries (Urban et al. 1986), breeding on low-lying offshore islands, coral flats, sandbanks (del Hoyo et al. 1996) and flat sandy beaches (Snow and Perrins 1998), foraging in the surf and over offshore waters (del Hoyo et al. 1996). Diet Its diet consists predominantly of small pelagic fish (Urban et al. 1986, del Hoyo et al. 1996) and shrimps (del Hoyo et al. 1996). Breeding site The nest is a shallow scrape (del Hoyo et al. 1996) on ridges or bare areas surrounded by vegetation (del Hoyo et al. 1996) on flat sandy beaches (Snow and Perrins 1998), low-lying sandy islands, coral flats, small coral islets and sandbanks (del Hoyo et al. 1996).
Systems: Terrestrial; Marine
Continuing decline in area, extent and/or quality of habitat: Unknown
Generation Length (years): 11
Movement patterns: Full Migrant
Congregatory: Congregatory (and dispersive)

Citation: BirdLife International. 2015. Thalasseus bengalensis. The IUCN Red List of Threatened Species 2015: e.T22694561A85103695. . Downloaded on 01 December 2015.
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