Thalasseus bengalensis emigrata
Family: Laridae
Length: 43 cm
Wingspan: 88 – 105 cm
Weight: 185 – 260 g
Identification
Appearance: medium-sized tern with a black cap, long yellow-orange bill and black legs. Grey upperwings, rump and central tail feathers, white underparts. In winter, the forehead becomes white.
Distinguishing characteristics: bill proportionally longer and more orange than Great Crested Tern. Grey upperwing (unlike Sandwich Tern).
Flight: agile flight with fairly quick wingbeats.
Sound: high-pitched grating « kreek » call.
Ecology and habitat
Nest: in a ground scrape on flat sandy beaches, low-lying sandy islands and sandbank.
Diet: mainly small pelagic fish and shrimps.
Behaviour at sea: forages by plunging headfirst into water from flight and emerging immediately with fish held in bill.
* This map indicates coastal nesting sites in the Mediterranean and adjacent Seas.
Distribution and movement
Breeding: this subspecies breeds on the southern Mediterranean coast on islands off the coast of Libya. Irregular breeding has also been reported in Italy, Spain, Greece and France.
Wintering: in southern Europe and Africa.
Phenology: Laying: May-June; one to two (rarely three) eggs. Incubation: 21-26 days. Chick-rearing. Fledging: 1 month after hatching.
Conservation
Global population estimate: 225,000 pairs in total (including the two other subspecies); the Mediterranean subspecies does not exceed 2,400 pairs.
Threats: illegal waterfowl hunting, habitat alteration, Illegal blast fishing, climate change, over-fishing, pollution, invasive or introduced species.
Protection level: Barcelona Convention: Annex II; African Eurasian Waterbird Agreement; Convention on Migratory Species: Appendix II; IUCN Red List: Least Concern.
Some key references
BirdLife International (2021) Species factsheet: Thalasseus bengalensis.
del Hoyo J., Elliott A., Sargatal, J. 1997. Handbook of the birds of the world (Vol. 4). Barcelona: Lynx edicions, 679 p.
Hamza A, Azafzaf H, Yahia J. 2012. State of knowledge and population trends of the Lesser Crested Tern Sterna bengalensis emigrata in the Mediterranean: threats identified and proposed actions for small islands in the Mediterranean. Proceedings of the 13th Medmaravis Pan-Mediterranean Symposium, Alghero, Sardinia, Italy, 14–17 October 2011. Medmaravis, pp 171–177.
Hamza A., Baccetti N., Sultana J., Yahia J., Zantello M., De Faveri A., Cutts N., Borg J., Azafzaf H., Defos du Rau P., Bourass E., Etayeb K., Elliott M. 2017. Migration flyway of the Mediterranean breeding Lesser Crested Tern Thalasseus bengalensis emigratus. Ostrich 88(1): 53-58.