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 is very large, and hence does not 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 is estimated to number 50,000-499,999 mature individuals (Partners in Flight 2019).
The species is undergoing a moderate decline (Partners in Flight 2019), which is thought to be caused by the drainage of wetlands and urban development (Ferguson-Lees and Christie 2001).
Text account compilers
Harding, M., Butchart, S. & Ekstrom, J.
BirdLife International (2022) Species factsheet: Busarellus nigricollis. Downloaded from http://www.birdlife.org on 24/05/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/05/2022.