Search:
Advance search
 

Aves > Charadriiformes > Laridae > Sterna

Sterna acuticauda J.E. Gray, 1831 – Black-bellied Tern

Taxonomic Notes:

Old Taxonomy: Sterna melanogaster Temminck, 1827.

This species is listed as Endangered in the IUCN Red List of Threatened Species (https://www.iucnredlist.org/).

Nesting/juveniles:

Breeding Season: March and April.

Nest: Its nest is a small shallow scrape or just a dimple in the bare sand on sandpits, large sandy islands, lakes, rivers. It nests in medium-to-large colonies often with River Tern, Indian skimmer and Small Pratincole. 

Eggs: 2-4, broad oval shaped, dark sandy coloured with greenish tinge and speckled with reddish spots.
           Average size = 32.4 x 24.9 mm.
Indian and global distribution:
records (based on images):
Identification:

Size: Medium sized bird, comparable with House Crow, length = approximately 33 cm.

Distinguishing Characters:

Adult: In breeding season it can be easily distinguished by having red-orange beak, dark glossy black cap, crown, nape and distinct black belly which gives it its English Name. It has a deeply forked tail. Look similar to immatures in non-breeding season having white underparts, shorter tail, and black streaks on crown. Both sexes are alike.

Youngs/Immatures: Buffy Grey, the feathers edged paler buffy white and subedged blackish. they often show yellow beak (against bright red-orange beak in adults).

Similar Species in India: River Tern (it lacks black colour to its belly), Whiskered Tern in its black-bellied breeding plumage (it lacks the deeply forked tail but has rather square-ended tail).


Sexual, seasonal & individual variation:

There is no sexual dimorphism that exists for this species. It developes dark black belly and bright red-orange beak in the breeding plumage. In non-breeding season, it loses the black colour of its belly, has white head with black streaks, and black patch behind eyes. 

Some individuals do not develop black belly completely (black colour restricted to lower belly and vent) in the breeding season. While some others can have only black cap and white underparts. No discernible iindividual variation exists. 

Status, Habitat and Habits:

This species is rare. It inhabits inland wetlands of India, Nepal, and Pakistan, from the sea level up to 700m. This species is found to be possibly extinct in Laos, Thailand, Cambodia, and Vietnam (BirdLife International 2017). In India, several smaller isolated populations are recorded from Maharashtra, Goa, Karnataka, Kerala, Gujarat, Odhisha, Uttar Pradesh, and Bihar.

Food: Freshwater fishes, crustaceans, and insects.

Behaviour: It remains in small to medium sized flocks. Often fly over the rivers, lakes to look for surfacing fishes/crustaceans. Individuals hunt either by skimming or diving in shallow as well as deep water. do not venture to hunt in heavy flowing water. Forages along with other tern species but does not show kleptoparasitism.

Call/Song: Shrill krek...krek... utterd constantly while flying. It is otherwise silent.

Migration Status: Resident. Largest population exists in India, Bangladesh, Nepal and Pakistan. It is possibly extinct from Myanmar.

Conservation Status:

This species is listed as Endangered in the IUCN Red List of Threatened Species (https://www.iucnredlist.org/).


According to the IUCN Red List Assessment, the population of this species is declining, with the current population size estimated at 6,700-17,000 individuals. The threat to its persistence comes from its breeding habitat degradation due to large scale agriculture, sand mining, dam building and aquaculture (BirdLife International 2001). 

References:

1. Rasmussen, P. C., and J. C. Anderton. 2005. 
Birds of South Asia: The Ripley Guide. Washington, DC.

2. Ali, S., and S. D. Ripley. 1981. Handbook of the Birds of India and Pakistan: Together with those of Nepal, Sikkim, Bhutan and Ceylon (Vol. 3). Oxford University Press.

3. Stuart Baker, E. C. 1933. The Nidification of Birds of the Indian Empire. Taylor And Francis, London.

4. BirdLife International 2017. Sterna acuticauda (amended version of 2016 assessment). The IUCN Red List of Threatened Species 2017: e.T22694711A110488626.
https://dx.doi.org/10.2305/IUCN.UK.2017-1.RLTS.T22694711A110488626.en. Accessed on 31 January 2020.


Aves > Charadriiformes > Laridae > Sterna


Cite this page along with its URL as:
Bhavanarayeni, R., and A. Bayani. 2020. Sterna acuticauda J.E. Gray, 1831 – Black-bellied Tern. Satose, V., A. Bayani, V. Ramachandran, P. Roy, and K. Kunte (Chief Editors). Birds of India, v. 2.17. Indian Foundation for Butterflies.
http://www.birdsofindia.org/sp/1060/Sterna-acuticauda
Share on facebook email page Share by email