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 <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). 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 (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The global population has not been quantified owing to recent taxonomic splits.
The overall population trend is decreasing, although some populations may be stable and others have unknown trends (Wetlands International 2006).
This species has declined markedly in Japan since the 1960s due to pollution and the disturbance of nesting colonies (Hancock and Kushlan 1984, del Hoyo et al. 1992).
Text account compilers
Butchart, S., Ekstrom, J., Malpas, L., Symes, A. & Taylor, J.
BirdLife International (2019) Species factsheet: Ardea intermedia. Downloaded from http://www.birdlife.org on 10/12/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 10/12/2019.