Derivation
Bo-taür'-us - probably a combination of two Latin words for bull (bos + taurus = botaurus): pöï-ci-lop'-til-us - Gk, poiclos, mottled; Gk, ptilon, feather
Habitat
Terrestrial wetlands, and occasionally estuarine habitats. Favours permanent freshwater, particularly those dominated by sedges, rush, reeds or cutting grass, growing over peaty or muddy ground.
South-western and south-eastern Australia, Tasmania and New Zealand. New Caledonia and Loyalty Is.
 
Rarity Status
Currently this species is not classified as a rarity in this country OR information has not been updated.
Population
Estimated population is 1,000 - 2,499 (2010) and decreasing.
Status EN
Wetland drainage for agriculture, as well as increased salinity of its habitats are the main threats.
For more information see BirdLife International Species Factsheet.
Food
Fish, frogs, yabbies and other aquatic life.
Voice
An abrupt, harsh, 'craaak!' is uttered in alarm. At night, during spring and summer, males utter a deep, resonant, two-syllable, booming, 'oo-oom, oo-oom', repeatedly.
Australasian Bittern (Botaurus poiciloptilus) [XC207686]
by John Graff from Christchurch, Christchurch City, Canterbury, New Zealand (song)
Australasian Bittern (Botaurus poiciloptilus) [XC165265]
by id from Manypeaks, Western Australia, Australia (call)
Nest
A well-structured flat saucer of flat peices of reeds or rushes, in a stand of rushes, about 2.5 m in height, in swamps. Semi-colonial.
Eggs (Guide)
4 - 6; olive-brown; oval; about 52 x 38 mm. Incubation: about 25 days; by female.
Young
Fledge in about 28 days, but venture out from the nest into the surrounding reeds after several weeks.
Subspecies
Forms a superspecies with Eurasian Bittern (Botaurus stellaris). Sometimes considered a subspecies of Eurasian Bittern (Botaurus stellaris). A population of south-western Australia has been proposed as a distinct subspecies westralensis, and birds from New Zealand subspecies maorensis.
No subspecies.
Similar Species
Juvenile Rufous Night-Heron (Nycticorax caledonicus) which is smaller, with a lighter build, and has a more hunched appearance.
References
See References.
The Field Guide to the Birds of Australia Pizzey, G., and Knight, E., 1997, Angus & Robertson, Sydney ISBN 0 207 19691 5
Field Guide to Australian Birds Morecombe, M., 2000, Steve Parish Publishing Pty Ltd. ISBN 1 876282 10 X
Field Guide to the Birds of Australia Simpson, K., and Day, N., 1999, 6th Edition, Viking ISBN 0 670 87918 5
Reader's Digest Complete Book of Australian Birds 1988, 2nd Edition, Reader's Digest ISBN 0 949819 99 9
What Bird is That? 1984, Revised Edition, Angus & Robertson, Sydney ISBN 0 207 14846 5
Handbook of Australian, New Zealand & Antarctic Birds 1990 - , Oxford University Press, Melbourne ISBN 0 19 553244 9