Intermediate egret

Intermediate egret
Ardea intermedia of breeding plumage in Northern Territory, Australia
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Aves
Order:Pelecaniformes
Family:Ardeidae
Genus:Ardea
Species: A. intermedia
Binomial name
Ardea intermedia
(Wagler, 1827)
     Breeding range     Year-round range     Wintering range     Present during migration
Synonyms

Mesophoyx intermedia
Egretta intermedia

The intermediate egret, median egret, smaller egret, or yellow-billed egret (Ardea intermedia) is a medium-sized heron. Some taxonomists put the species in the genus Egretta or Mesophoyx. It is a resident breeder from east Africa across the Indian subcontinent to Southeast Asia and Australia.

Description

This species, as its scientific name implies, is intermediate in size between the great egret and smaller white egrets like the little egret and cattle egret, though nearer to little than great. It is about 56–72 cm (22–28 in) long with a 105–115 cm (41–45 in) wingspan and weighs c. 400 g (14 oz),[2] with all-white plumage, generally dark legs and a thickish yellow bill. Breeding birds may have a reddish or black bill, greenish yellow gape skin, loose filamentous plumes on their breast and back, and dull yellow or pink on their upper legs (regional variations). The sexes are similar.[3]

Differences from great egret

Sketch comparing gapes of intermediate and great egrets

The non-breeding colours are similar, but the intermediate is smaller, with neck length a little less than body length, a slightly domed head, and a shorter, thicker bill. The great egret has a noticeable kink near the middle of its neck, and the top of its longer bill nearly aligns with the flat top of its head. Close up, great egret's gape line extends behind the eye, while the intermediate's is less pointed and ends below the eye. The intermediate tends to stalk upright with neck extended forward. The great is more patient, often adopting a sideways-leaning "one-eyed" stance.

Differences from little egret

Little egrets have yellow-soled feet and black bills. They often run after fish in shallow water. Breeding birds have long nuptial plumes on the back of their heads.

Behaviour

The intermediate egret stalks its prey methodically in shallow coastal or fresh water, including flooded fields. It eats fish, frogs, crustaceans and insects. It often nests in colonies with other herons, usually on platforms of sticks in trees or shrubs. Two to five eggs are laid, the clutch size varying with region.

In Northern Territory, Australia

References

  1. ↑ BirdLife International (2012). "Ardea intermedia". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
  2. ↑ del Hoyo, J., Elliott, A. and Sargatal, J. (1992). Handbook of the Birds of the World. Volume 1: Ostrich to Ducks. Lynx Edicions, Barcelona.
  3. ↑ Ali, S. (1993). The Book of Indian Birds (11 revised ed.). Bombay: Bombay Natural History Society/Oxford University Press. ISBN 0195621670.

Other references

  • Birds of The Gambia by Barlow, Wacher and Disley, ISBN 1-873403-32-1
  • Birds of India by Grimmett, Inskipp and Inskipp, ISBN 0-691-04910-6
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.