Hoary-headed grebe
{{Short description|Species of bird}}
{{Speciesbox
| name = Hoary-headed grebe
| image = Hoary-headed Grebe 0A2A6268.jpg
| image_caption = breeding plumage
| image2 = Hoary-headed grebe (Poliocephalus poliocephalus) non breeding Adelaide.jpg
| image2_caption = non-breeding plumage
| status = LC
| status_system = IUCN3.1
| genus = Poliocephalus
| species = poliocephalus
| authority = (Jardine & Selby, 1827)
| range_map = Hoary-headed Grebe.png
| range_map_caption = 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; it winters throughout the island of Tasmania. 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.{{Cite web | url = http://www.ozanimals.com/Bird/Hoary-headed-Grebe/Poliocephalus/poliocephalus.html | title = Hoary-headed Grebe ( Poliocephalus poliocephalus ) | publisher = Ozanimals.com | access-date = 7 November 2012}} 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.Trounson, D.& M. (2008) Australian Birds: A concise Photographic Field Guide. Murray David Publishing, Smithfield, NSW {{ISBN|978-0-9752428-4-1}}
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.Pizzey, G. and Knight, F. (1997). Field Guide to the Birds of Australia. Angus and Robertson, Sydney. {{ISBN|0-00-219201-2}} The hoary-headed grebe is usually found away from the shoreline in large open waters, which may be estuarine, brackish or freshwater.{{Cite web | url = http://birdsinbackyards.net/species/Poliocephalus-poliocephalus | publisher = Birds in Backyards | access-date = 7 November 2012| title = Hoary-headed Grebe}} It can also be found in sheltered coastal seas.{{cite book |last=Flegg |first=J. |author-link=Jim Flegg |date=2002 |title=Photographic Field Guide Birds of Australia |publisher=Reed New Holland |location=Frenchs Forest, NSW |isbn=978-1-876334-78-9}} It can sometimes be found in New Zealand, where it is much less common than Australia.{{Cite web | url = http://www.birdlife.org/datazone/speciesfactsheet.php?id=3635 | publisher = Birdlife International | access-date = 2 February 2013 | title = Hoary-headed Grebe | archive-date = 24 September 2015 | archive-url = https://web.archive.org/web/20150924171458/http://www.birdlife.org/datazone/speciesfactsheet.php?id=3635 | url-status = dead }}
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.Pizzey, G. and Knight, F. (1997). Field Guide to the Birds of Australia. Angus and Robertson, Sydney.{{ISBN|0-00-219201-2}}
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.Morcombe, M. (2003) Field Guide to Australian Birds: Australia's Most Comprehensive Guide. Steve Parish Publishing, Sydney.{{ISBN|9781740214179}}
Conservation
With a large range and no evidence of significant population decline, this species’ conservation status is of Least Concern.
References
{{Reflist}}
- Grebes of the World – Malcolm Ogilvie & Chris Rose {{ISBN|1-872842-03-8}}
{{Grebes}}
{{Taxonbar|from=Q904167}}
Category:Birds of Western Australia
Category:Birds of South Australia
Category:Birds of New South Wales
Category:Birds of Victoria (state)
Category:Endemic birds of Australia
Category:Birds described in 1827
Category:Taxa named by Sir William Jardine