Chlidonias hybrida 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Charadriiformes Laridae

Scientific Name: Chlidonias hybrida (Pallas, 1811)
Regional Assessments:
Common Name(s):
English Whiskered Tern
French Guifette moustac
Chlidonias hybridus ssp. hybridus — Sibley and Monroe (1990, 1993)
Chlidonias hybridus ssp. hybridus — Dowsett and Forbes-Watson (1993)
Chlidonias hybridus ssp. hybridus — Christidis and Boles (1994)
Chlidonias hybridus ssp. hybridus — Cramp and Simmons (1977-1994)
Taxonomic Source(s): Christidis, L. and Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. CSIRO Publishing, Collingwood, Australia.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2017
Date Assessed: 2016-10-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Dowsett, R.J.
Facilitator/Compiler(s): Ashpole, J, Butchart, S., 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 fluctuating, 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:

Geographic Range [top]

Countries occurrence:
Afghanistan; Albania; Algeria; Angola; Armenia; Australia; Austria; Azerbaijan; Bahrain; Bangladesh; Belarus; Benin; Bosnia and Herzegovina; Botswana; Brunei Darussalam; Bulgaria; Cambodia; Central African Republic; Chad; China; Côte d'Ivoire; Croatia; Cyprus; Czech Republic; Egypt; Equatorial Guinea; Ethiopia; France; Gambia; Germany; Ghana; Greece; Guam; Guinea; Guinea-Bissau; Hong Kong; Hungary; India; Indonesia; Iran, Islamic Republic of; Iraq; Israel; Italy; Japan; Jordan; Kazakhstan; Kenya; Korea, Republic of; Kuwait; Lao People's Democratic Republic; Latvia; Lebanon; Liberia; Libya; Lithuania; Macedonia, the former Yugoslav Republic of; Madagascar; Malawi; Malaysia; Mali; Mauritania; Micronesia, Federated States of ; Moldova; Mongolia; Montenegro; Morocco; Mozambique; Myanmar; Namibia; Nepal; Niger; Nigeria; Northern Mariana Islands; Oman; Pakistan; Palau; Palestinian Territory, Occupied; Papua New Guinea; Philippines; Poland; Portugal; Qatar; Romania; Russian Federation (Central Asian Russia, Eastern Asian Russia, European Russia); Saudi Arabia; Senegal; Serbia; Sierra Leone; Singapore; Slovakia; Somalia; South Africa; South Sudan; Spain; Sri Lanka; Sudan; Swaziland; Switzerland; Syrian Arab Republic; Taiwan, Province of China; Tajikistan; Tanzania, United Republic of; Thailand; Timor-Leste; Togo; Tunisia; Turkey; Turkmenistan; Uganda; Ukraine; United Arab Emirates; Uzbekistan; Viet Nam; Western Sahara; Yemen; Zambia; Zimbabwe
Barbados; Belgium; Burkina Faso; Burundi; Cameroon; Cape Verde; Christmas Island; Congo, The Democratic Republic of the; Denmark; Djibouti; Eritrea; Finland; Gibraltar; Iceland; Ireland; Lesotho; Luxembourg; Maldives; Malta; New Zealand; Norway; Rwanda; Seychelles; Sweden; United Kingdom; United States
Additional data:
Continuing decline in area of occupancy (AOO):Unknown
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:130000000
Continuing decline in extent of occurrence (EOO):UnknownExtreme 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):2000
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The global population is estimated to number c.300,000-1,500,000 individuals (Wetlands International 2015). The European population is estimated at 66,300-108,000 pairs, which equates to 133,000-215,000 mature individuals (BirdLife International 2015). National population estimates include: c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in China; c.50-10,000 wintering individuals in Taiwan; < c.1,000 individuals on migration in Korea; c.50-1,000 individuals on migration and < c.50 wintering individuals in Japan and c.100-10,000 breeding pairs and c.50-1,000 individuals on migration in Russia (Brazil 2009).

Trend Justification:  The overall population trend is fluctuating, although some populations are stable and others have unknown trends (Wetlands International 2015). The European population trend is estimated to be increasing (BirdLife International 2015).
Current Population Trend:Stable
Additional data:
Continuing decline of mature individuals:Unknown
Extreme fluctuations:NoPopulation severely fragmented:No
Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:Behaviour Northern breeding populations of this species are fully migratory whilst tropical breeders are more nomadic or locally dispersive (del Hoyo et al. 1996). The species breeds from May to early-June (Richards 1990) in monospecific colonies of 10-100 pairs (del Hoyo et al. 1996). After breeding it departs for the wintering grounds from late-July to September, returning again between April and May (Richards 1990). The species sometimes forages singly, but is more common in small groups or larger mixed-species flocks on passage and in the winter (Snow and Perrins 1998). Habitat The species utilises a variety of wetland habitats but shows a preference for freshwater marshlands with scattered pools, particularly where the surrounding vegetation is grazed by cattle or horses (Richards 1990). It frequents inland lakes, rivers, marshes, temporary pans (e.g. in Africa), artificial fish-ponds and drainage-ponds covered with water-lilies (e.g. in Italy) (del Hoyo et al. 1996), swamps, river pools, reservoirs, large dams, sewage-ponds, flooded saltmarshes, arable fields (e.g. in Australia) (Higgins and Davies 1996, del Hoyo et al. 1996) and rice-fields (del Hoyo et al. 1996). In Australia the species also occurs along the coast on estuaries, coastal lagoons, creeks in mangrove swamps (Snow and Perrins 1998) and tidal mudflats (del Hoyo et al. 1996). Diet Its diet consists of terrestrial and aquatic insects (del Hoyo et al. 1996) (e.g. Dytiscidae, adult and larval Odonata, Orthoptera, flying ants (del Hoyo et al. 1996) and mosquitoes (Richards 1990)), spiders, frogs, tadpoles, small crabs (del Hoyo et al. 1996), shrimps (Richards 1990) and small fish (del Hoyo et al. 1996). Breeding site The nest is a heap of aquatic vegetation (Richards 1990, del Hoyo et al. 1996) or dry grass (del Hoyo et al. 1996), placed either on floating and emergent vegetation over water 60-80 cm deep or resting on the bottom of very shallow water (del Hoyo et al. 1996). The species nests in colonies, neighbouring pairs spaced between 1 and 5 m apart (del Hoyo et al. 1996), and may forage up to 9 km away from breeding sites (more usually within 1 km) (del Hoyo et al. 1996).
Systems:Terrestrial; Freshwater; Marine
Continuing decline in area, extent and/or quality of habitat:Unknown
Generation Length (years):9.9
Movement patterns:Full Migrant
Congregatory:Congregatory (and dispersive)

Threats [top]

Major Threat(s): The species suffers nest destruction from the invasive rodent species Myocastor coypus in Italy (Arduin 1997). Within its European range it suffers from the loss of natural wetlands to land reclamation, dry seasons and an increase in drainage schemes (Hagemeijer and Blair 1997), as well as the canalization of rivers (Tucker and Heath 1994). Additionally the following threats have been identified within its European range: increasing tourism and water sports near breeding colonies result in disturbance and the loss of nesting sites (Tucker and Heath 1994) and many nests are lost to adverse weather. It is affected by water quality and so pollution from insecticides and eutrophication are a threat (Martí and Moral 2004); In addition the intensification of fisheries and bycatch in fishing nets are issues (Golemansky 2011). Utilisation Large numbers of eggs are collected for sale and local consumption in India (this may be causing population declines in some areas) (del Hoyo et al. 1996), and fishermen collect eggs in Ukraine (del Hoyo et al. 1996).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
The following information refers to the species's European range only: Bern Convention Appendix II. The species has been included as a target species in three EU LIFE Projects.

Conservation Actions Proposed
The following information refers to the species's European range only: The species requires the maintenance of a network of water-bodies with well-developed emergent and floating vegetation to provide sufficient breeding habitat. These areas should be protected from disturbance by the establishment of buffer zones around them. Artificial, anchored rafts may be useful in providing nesting sites on intensively managed water-bodies (Tucker and Heath 1994).

Amended [top]

Amended reason: Added a country of occurrence and a Contributor. Edited Threats Information text.

Citation: BirdLife International. 2017. Chlidonias hybrida (amended version of 2016 assessment). The IUCN Red List of Threatened Species 2017: e.T22694764A111750380. . Downloaded on 24 May 2018.
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