Gygis alba   (Sparrman,  1786) (Bird)
Organism information awaits expert curation
Taxonomy
Kingdom:Animalia
Phylum:Chordata
Class: Aves
Order:Charadriiformes
Family:Laridae

Image copyright: pbase

Description
Length:28-33cm, Wing:23-26cm, Wingspan: 66-78cm, Tail: 10-12cm, Bill: 37-46mm, Tarsus: 12-18cm,Weight:100-140g

With its wholly white plumage, the White Tern is unique among terns. The feathers are so white that the wings may appear translucent in flight. The species is a medium sized tern, which has no plumage variation during breeding. The tail is long with a shallow fork. The bill, eyes and eye rings are black and the legs and feet are greyish. Individuals are faintly smudged with ginger color around the head and on the back and wings.

Call: The principal call of the White Tern is a repeated guttural heech heech. Adult and young White Terns are generally quiet at the nest site.

Habitat:The White Tern is pelagic and, although the non-breeding range is unknown, the species is generally thought to disperse into oceanic areas relatively close to breeding islands. The species is migratory or dispersive and often encountered singly or in small groups.

The White Tern is diurnal, although dusk and dawn are probably important feeding times. Individuals feed both inshore and offshore generally dipping their bill to catch prey at or just below the ocean surface. White Terns have frequently been observed returning to their nesting tree with five or six fish held crosswise in their bill, indicating that they have the necessary skill to catch fish with their bill while already holding others. Feeding is generally solitary but may occur with mixed species flocks.

Nesting season: Individuals appear to breed at almost any time of the year and breeding behaviour may vary considerably throughout the species range.
Nest- No nest is made but bark may be scratched away with feet and discarded with the bill. Eggs- single egg, Both
parents incubate a single egg for at least 28
days and care for the young. Fledging occurs at 60 to 75 days and then juveniles accompany parents to forage at sea.

Synonym (s)

Common Name (s)
• White Tern (English)
• Angel Tern (English)
• Fairy Tern (English)
• Indian Ocean White Tern (English)
• Cundu, Wallu dooni
• Common White-Tern (English)
Economic Importance and Threats
Threats:  Natural threats
(· Stochastic events impacting upon small populations
· Strong winds, dislodging the precariously placed egg
· Predation by cats, the Nankeen Kestral, the Masked Owl and the Pied Currawong
·Black Ant may attack young
)

Ecology
Habitat:  Pelagic, Open Sea, Coastal
Trophic Level:  Consumer
Prey:  fish and other small aquatic animals that are 2-8 cm long
IUCN Status:  Least Concern

Biogeography


• Narcondam Island, Andaman and Nicobar Islands INDIA

Literature Source(s)
  • (2003) IUCN Red list of threatened species Available at - http://www.iucnredlist.org/
  • Avibase- the world database Available at - http://avibase.bsc-eoc.org
  • Integrated Taxonomic Information System (ITIS) Available at - http://www.itis.gov.
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at - http://www.marinespecies.org
  • Vernacular names of the Birds of the Indian Subcontinent Buceros, Envis newsletter: Avian Ecology & Inland Wetlands 62pp Available at - http://www.bnhsenvis.nic.in/pdf/BUCEROS%203%20(1).pdf
  • Standardized English names of the Birds of the Indian Subcontinent ENVIS Newsletter: Avian Ecology and Inland Wetland 55pp Available at - http://www.bnhsenvis.nic.in/pdf/BUCEROS%203%20(2).pdf
  • Manakadan R and Pittie A (2001) Standardized English names of the Birds of the Indian Subcontinent BUCEROS Envis Newsletter: Avian ecology and inland wetland 6(1) 26pp Available at - http://www.bnhsenvis.nic.in/pdf/BUCEROS%206%20(1).pdf
  • iNaturalist.org Available at - http://www.inaturalist.org
  • PBase Available at - http://www.pbase.com/

Page last updated on:2013-03-07

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