Black-fronted tern

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Black-fronted tern
Black-fronted tern in splendid dress (above) together with a Tara tern (below)

Black-fronted tern in splendid dress (above) together with a Tara tern (below)

Systematics
Class : Birds (aves)
Order : Plover-like (Charadriiformes)
Family : Terns (Sternidae)
Genre : Common Terns ( Chlidonias )
Type : Black-fronted tern
Scientific name
Chlidonias albostriatus
( GR Gray , 1845)

The black-fronted tern ( Chlidonias albostriatus , syn .: Sterna albostriata ) is a species of bird from the family of the tern (Sternidae). The species is also known in its New Zealand range as Black-fronted Tern , Sea Martin , Plowboy , Inland Tern or Riverbed Tern . The Māori name for the bird is Tarapiroe .

Appearance

The small tern reaches 29 cm in length. The adult birds have a predominantly gray plumage with the black cap typical of many terns, which extends to the beak in its splendid dress . The underside and rump are white and a narrow white stripe runs below the cap along the cheek. The tail is short and forked. The very short legs are, like the beak in a splendid dress, light orange. The black cap withdraws from the beak when it is at rest , is then reduced to an arc that extends from eye to eye and becomes white spotted. The tip of the beak becomes dark in the resting dress.

Fledglings and immature birds are similar to the adult birds in their resting plumage, but the top of the head and neck are heavily dashed or spotted in black and on the back they are scaled a little yellow-brown. Their beak is dark brown and dull orange at the base.

distribution and habitat

The species lives in and around freshwater areas and on river banks on the southern tip of the North Island and over much of the eastern South Island of New Zealand from the Marlborough region to Southland and on Stewart Island . An isolated population lives on the Buller River and the upper reaches of the Motueka River in southern Nelson. The breeding areas are only on the South Island. Outside the breeding season, they are up to 10 km out to sea in search of food.

Danger

The species is on the Red List of IUCN (Endangered, EN) as "critically endangered" out. The populations are threatened by introduced mammals and birds. Among them are weasels ( Mustela spp.), Feral domestic cats, brown rats , hedgehogs, dogs and the Australian-born fox kusu and the flute bird . Cattle, sheep and people's leisure activities disrupt the hatchery business. Furthermore, hydropower projects and river engineering threaten the birds. The stocks are in decline in the entire distribution area.

Clutch of the black-fronted tern

Way of life

The black-fronted tern breeds in a simple nest hollow in river beds. The clutch usually consists of two eggs. The young are fledged after about 30 days.

The black-fronted tern eats fish and invertebrates in fresh water. Occasionally it takes earthworms and other invertebrates ashore. At sea, the black-fronted tern feeds mainly on crustaceans.

Taxonomy

The black-fronted tern was first described by George Robert Gray in 1845 . The species name is derived from the Latin albus "white" and striatus "striped". It is one of four species of swamp, offshore, tern of the genus Chlidonias . The genus is considered by some authors to be part of the larger Sterna genus .

The species has several common names. It owes the name plowboy or plowman's friend to the habit of looking for worms and caterpillars on freshly plowed areas.

Individual evidence

  1. ^ Rod Morris, Alison Ballance: Rare Wildlife of New Zealand . Random House, Auckland 2008, ISBN 978-1-86941-912-7 .
  2. ↑ a b c M. Bell: Black-fronted tern. In Miskelly, CM (ed.) New Zealand Birds Online. 2013 ( online )
  3. ↑ a b c d e Species factsheet: Sterna albostriata . In: BirdLife International . 2009. Accessed December 31, 2009.
  4. ↑ David P. Simpson (Ed.): Cassell's Latin Dictionary . 5th ed. Cassell, London 1979, ISBN 0-304-52257-0 (reprint of the New Yorek 1963 edition).
  5. ↑ Gerard Hutching : Gulls, terns and skuas . In: Te Ara - the Encyclopedia of New Zealand . Ministry for Culture & Heritage , February 17, 2015, accessed September 18, 2018 .

Web links

Commons : Black-fronted Tern ( Chlidonias albostriatus )  - Collection of images, videos and audio files