EN
Australasian Bittern Botaurus poiciloptilus



Taxonomy

Taxonomic source(s)
Christidis, L. and Boles, W.E. 2008. Systematics and taxonomy of Australian birds. CSIRO Publishing, Collingwood, Australia.
Christidis, L.; Boles, W. E. 2008. Systematics and taxonomy of Australian birds. CSIRO Publishing, Collingwood, Australia.
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.
Turbott, E. G. 1990. Checklist of the birds of New Zealand. Ornithological Society of New Zealand, Wellington.
Turbott, E.G. 1990. Checklist of the birds of New Zealand. Ornithological Society of New Zealand, Wellington.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- C1 A2bc+3bc+4bc; C1

Red List history
Year Category Criteria
2016 Endangered C1
2013 Endangered C1
2012 Endangered C1
2009 Endangered C1
2008 Endangered
2006 Endangered
2004 Endangered
2000 Vulnerable
1996 Endangered
1994 Endangered
1988 Lower Risk/Least Concern
Species attributes

Migratory status not a migrant Forest dependency Does not normally occur in forest
Land mass type Land-mass type - Australia
Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 10,300,000 medium
Number of locations 11-100 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 1000-2499 poor estimated 2009
Population trend Decreasing poor estimated -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 30-49 - - -
Decline (10 years/3 generation past and future) 30-49 - - -
Number of subpopulations 2-100 - - -
Largest subpopulations 1-89 - - -
Generation length (yrs) 5.5 - - -

Population justification: In New Zealand, the estimated population was between 580-725 individuals in 1980. The population on New Caledonia is not thought to exceed 50 individuals. Following apparently rapid declines, the Australian population is now thought to number fewer than 1,000 mature individuals (R. Loyn in litt. 2008). The total population is best placed in the band 1,000-2,499 mature individuals, equating to 1,500-3,749 individuals in total, rounded here to 1,500-4,000 individuals.

Trend justification: Population trends are unknown for the small New Caledonian population, whilst in New Zealand (c.40% of the global population) the species is suspected to be stable. In Australia, however, reporting rates in atlas surveys have declined by 77% since the first atlas in 1977-1981 and 58% since the second atlas in 1998-2003. This equates to an overall population decline of c.38% over the past three generations, or 26% over the past two generations.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Australia N Extant Yes
New Caledonia (to France) U Extant Yes
New Zealand N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Australia Barmah-Millewa
Australia Bellarine Wetlands
Australia Benger Swamp
Australia Carrum Wetlands
Australia Coorong
Australia Discovery Bay to Piccaninnie Ponds
Australia Egg Islands (Huon Estuary)
Australia Fivebough and Tuckerbil Swamps
Australia Griffith Wetlands
Australia Gulf St Vincent
Australia Gwydir Wetlands
Australia Hastings-Macleay
Australia Hunter Estuary
Australia Lake Hawdon System
Australia Lake Pleasant View System
Australia Lakes Alexandrina and Albert
Australia Lower Brodribb River
Australia Macquarie Marshes
Australia Muir-Unicup Wetlands
Australia Narran Wetlands
Australia North Victorian Wetlands
Australia Owingup Swamp and Boat Harbour Wetlands
Australia Two Peoples Bay and Mount Manypeaks
Australia Yambuk
New Zealand Ahuriri River
New Zealand Ashburton River
New Zealand Bay of Plenty Islands
New Zealand Bluff Harbour Awarua Bay
New Zealand Eglington River
New Zealand Farewell Spit
New Zealand Firth of Thames
New Zealand Godley Cass Rivers
New Zealand Kaipara Harbour
New Zealand Maketu
New Zealand Mangawhai
New Zealand Ohau Pukaki Tekapo Rivers
New Zealand Omaui Island Oreti Estuary
New Zealand Orari River
New Zealand Papakanui Spit
New Zealand Pegasus Bay Coast
New Zealand Te Waihora
New Zealand Waipu Estuary
New Zealand Wairarapa Moana Ruamahanga

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Marine Intertidal Salt Marshes (Emergent Grasses) major resident
Wetlands (inland) Bogs, Marshes, Swamps, Fens, Peatlands major resident
Altitude 0 - 800 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Hunting & trapping terrestrial animals Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines
Stresses
Species disturbance, Species mortality
Climate change & severe weather Droughts Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines
Stresses
Ecosystem degradation
Natural system modifications Dams & water management/use Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines
Stresses
Ecosystem degradation
Natural system modifications Other ecosystem modifications Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines
Stresses
Ecosystem degradation
Transportation & service corridors Utility & service lines Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines
Stresses
Species mortality

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Other (free text) - - - Non-trivial Recent
Sport hunting/specimen collecting - - - Non-trivial Recent

Recommended citation
BirdLife International (2017) Species factsheet: Botaurus poiciloptilus. Downloaded from http://www.birdlife.org on 12/12/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 12/12/2017.