Data Zone
Justification of Red List category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence under 20,000 km² combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population size may be small, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (under 10,000 mature individuals with a continuing decline estimated to be over 10% in ten years or three generations, or with a specified population structure). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (over 30% decline over ten years or three generations). For these reasons the species is evaluated as Least Concern. The status of this species was recently reassessed against the IUCN Red List criteria at national level for the Action Plan for Australian Birds 2020 (Garnet and Baker 2021), and not found to approach or meet the thresholds for threatened status, thereby supporting its continuing treatment as globally Least Concern.
Population justification
Garnett and Crowley (2000) estimated the population size as follows: fewer than 500 pairs (equating to 1,000 individuals) in Victoria, approximately 1,000-1,500 pairs in north-east New South Wales (approximately 2,000-3,000 individuals) and approximately 125 pairs (equating to 250 individuals) in south-east New South Wales. This gives an overall population estimate of between 3,250 and 4,250 individuals, equating roughly to 2,200-2,800 mature individuals. Garnett and Crowley (2000) state that the current population is stable and broadly similar to pre-European population levels. The species is equally able to live and breed in heavily logged, lightly logged or unlogged forest.
Trend justification
Garnett and Crowley (2000) state that the current population is stable and broadly similar to pre-European population levels. The species is equally able to live and breed in heavily logged, lightly logged or unlogged forest.
This species occurs in open forest and woodlands in eastern Australia, from south-west Victoria to at least Eungella, and possibly Bowen, Queensland. Large areas of the species' range are now unsuitable as a result of clearing for agriculture and pastoralism, although the species now occupies suburban Brisbane, Sydney and Melbourne.
Although densities in remaining forest may eventually be affected by a reduction in the availability of suitable nest hollows and den sites as a result of intensive forestry practices, studies indicate birds persist in mosaics of unlogged forest, in which they nest, and logged forest, in which they forage. There was no difference in density between heavily logged, lightly logged and unlogged forest. Intense wildfire can result in local loss but, if suitable habitat remains nearby, they may return to forage. Poisoning, disturbance and predation by foxes may also cause nest failure and some mortality, but are unlikely to be significant (Garnett and Crowley 2000).
Text account compilers
Rutherford, C.A.
Contributors
Garnett, S.
Recommended citation
BirdLife International (2024) Species factsheet: Powerful Owl Ninox strenua. Downloaded from
https://datazone.birdlife.org/species/factsheet/powerful-owl-ninox-strenua on 28/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 28/11/2024.