Hoary-headed grebe

Hoary-headed grebe
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Podicipediformes
Family: Podicipedidae
Genus: Poliocephalus
Species: P. poliocephalus
Binomial name
Poliocephalus poliocephalus
(Jardine & Selby, 1827)
Distribution of the hoary-headed grebe

The hoary-headed grebe (Poliocephalus poliocephalus) is a member of the grebe family. It breeds in southern parts of Australia and Tasmania; it winters throughout the island. The bird takes its name from the silvery-white streaking on its black head. It is common in Australia, with a population of about 500,000. Its habitat is similar to that of the Australasian grebe.

Description

The hoary-headed grebe is a fairly small dark grey and white grebe. It has a brown eye and a black patch under the chin, and a narrow black streak down the back of the neck. During the breeding season the adult's plumage has white streaks over its entire head, giving them the common name of hoary-headed grebe. Juveniles have a white chin and throat and a striped face.[2] Males have two plumage phases: after breeding they lose the buff breast and the white lines on the head, but can usually be identified then by the broad black bar down the nape.[3]

Distribution and habitat

The hoary-headed grebe is found in all states and territories of Australia. It is generally absent from the central arid regions of Australia.[4] The hoary-headed grebe is usually found away from the shoreline in large open waters, which may be estuarine, brackish or freshwater.[5] It can also be found in sheltered coastal seas.[6] It can sometimes be found in New Zealand, where it is much less common than Australia.[7]

Food

The hoary-headed grebe feeds on aquatic arthropods, mostly caught by deep diving. This species feeds during the day, and when the light is poor, forages mostly at the water surface.[8]

Breeding

Hoary-headed grebes breed from August to January. The nests are a floating platform of water weeds, similar to that of the Australasian grebe, and usually some distance out from shore among sparse reeds or other plants, anchored to and at least partly supported by them. A shallow depression on top is just slightly above water, so the eggs are lying in water or dampness. The eggs are concealed under pieces of wet vegetation when the incubating parent leaves so that the nest appears empty. Under full sun the covered eggs are warm and moist, often left unattended for some time. The egg's appearance is oval, white, and soon stained brownish ochre, while the clutch is usually 2–5 eggs. Incubation is 20–24 days and egg size is 39 x 27 mm.[9]

Conservation

With a large range and no evidence of significant population decline, this species’ conservation status is of Least Concern.

References

  1. ↑ BirdLife International (2012). "Poliocephalus poliocephalus". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
  2. ↑ "Hoary-headed Grebe ( Poliocephalus poliocephalus )". Ozanimals.com. Retrieved 7 November 2012.
  3. ↑ Trounson, D.& M. (2008) Australian Birds: A concise Photographic Field Guide. Murray David Publishing, Smithfield, NSW ISBN 978-0-9752428-4-1
  4. ↑ Pizzey, G. and Knight, F. (1997). Field Guide to the Birds of Australia. Angus and Robertson, Sydney. ISBN 0-00-219201-2
  5. ↑ "Hoary-headed Grebe". Birds in Backyards. Retrieved 7 November 2012.
  6. ↑ Flegg, J. (2002) Photographic Field Guide Birds of Australia. Reed New Holland, Frenchs Forest, NSW ISBN 978-1-876334-78-9
  7. ↑ "Hoary-headed Grebe". Birdlife International. Retrieved 2 February 2013.
  8. ↑ Pizzey, G. and Knight, F. (1997). Field Guide to the Birds of Australia. Angus and Robertson, Sydney.ISBN 0-00-219201-2
  9. ↑ Morcombe, M. (2003) Field Guide to Australian Birds: Australia's Most Comprehensive Guide. Steve Parish Publishing, Sydney.ISBN 9781740214179
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