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Australasian Bittern Botaurus poiciloptilus

IUCN Red List Criteria

Critically Endangered  
Endangered C1 
Vulnerable A2bc+3bc+4bc; C1 

IUCN Red List history

Year Category
2013 Endangered
2012 Endangered
2009 Endangered
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 Australia
Average mass -

Distribution

  Estimate Data quality
Extent of Occurrence breeding/resident (km2) 1,430,000 medium
Number of locations 11-100 -
Fragmentation -

Population & trend

  Estimate Data quality Derivation Year of estimate
No. of mature individuals 1000-2499 poor Estimated 2009
Population trend Decreasing poor -
Number of subpopulations 2-100 - - -
Largest subpopulation - - -
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 Breeding Non-breeding Passage Resident
Australia Native Extant       Yes
New Caledonia (to France) Unknown Extant Yes      
New Zealand Native Extant       Yes

Important Bird Areas where this species has triggered the IBA criteria

Country/Territory IBA Name IBA link
Australia Barmah-Millewa site factsheet
Australia Bellarine Wetlands site factsheet
Australia Benger Swamp site factsheet
Australia Carrum Wetlands site factsheet
Australia Coorong site factsheet
Australia Discovery Bay to Piccaninnie Ponds site factsheet
Australia Egg Islands (Huon Estuary) site factsheet
Australia Fivebough and Tuckerbil Swamps site factsheet
Australia Griffith Wetlands site factsheet
Australia Gulf St Vincent site factsheet
Australia Gwydir Wetlands site factsheet
Australia Hastings-Macleay site factsheet
Australia Hunter Estuary site factsheet
Australia Lake Hawdon System site factsheet
Australia Lake Pleasant View System site factsheet
Australia Lakes Alexandrina and Albert site factsheet
Australia Lower Brodribb River site factsheet
Australia Macquarie Marshes site factsheet
Australia Muir-Unicup Wetlands site factsheet
Australia Narran Wetlands site factsheet
Australia North Victorian Wetlands site factsheet
Australia Owingup Swamp and Boat Harbour Wetlands site factsheet
Australia Two Peoples Bay and Mount Manypeaks site factsheet
Australia Yambuk site factsheet

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 / Agro-industry farming Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Decline Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Hunting & trapping terrestrial animals / Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Species disturbance, Species mortality
Climate change & severe weather Droughts Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Decline Low Impact: 5
Stresses
Ecosystem degradation
Natural system modifications Dams & water management/use / Abstraction of ground water (agricultural use) Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Decline Low Impact: 5
Stresses
Ecosystem degradation
Natural system modifications Other ecosystem modifications Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Decline Low Impact: 5
Stresses
Ecosystem degradation
Transportation & service corridors Utility & service lines Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Species mortality

Utilisation

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

Recommended citation
BirdLife International (2014) Species factsheet: Botaurus poiciloptilus. Downloaded from http://www.birdlife.org on 20/10/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 20/10/2014.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Key facts
Current IUCN Red List category Endangered
Family Ardeidae (Herons)
Species name author (Wagler, 1827)
Population size 1000-2499 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 1,430,000 km2
Country endemic? No
Links to further information
- Summary information on this species