Data Zone
Justification of Red List category
This species has a very 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 has not been quantified, 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). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to 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
The population is in decline owing to the effects of introduced predators and herbivores (del Hoyo et al. 2007).
Trend justification
The population is in decline owing to the effects of introduced predators and herbivores (del Hoyo et al. 2007).
This species is found in the shrublands of central Australia, although it is now extinct from its range in the south Northern Territory.
The extirpation of this species from parts of its range has been attributed to overgrazing by livestock, although there appears to be no significant effect at present. The reasons for its patchy distribution are not understood. Its range is almost all under pastoral management, and it is absent from apparently suitable habitat but can survive in sparsely-covered, degraded habitat (Garnett and Crowley 2000).
Text account compilers
Rutherford, C.A.
Contributors
Garnett, S.
Recommended citation
BirdLife International (2024) Species factsheet: Thick-billed Grasswren Amytornis modestus. Downloaded from
https://datazone.birdlife.org/species/factsheet/thick-billed-grasswren-amytornis-modestus on 22/12/2024.
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 22/12/2024.