| Citation |
BirdLife International 2017. Lanius bucephalus (amended version of 2016 assessment). The IUCN Red List of Threatened Species 2017: e.T22704998A118773936. https://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T22704998A118773936.en. Downloaded on 11 March 2020. |
Description |
JUSTIFICATION
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.
DESCRIPTION
The global population size has not been quantified, but the species is described as not uncommon (Harris and Franklin 2,000), while national population estimates include: c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in China; c.10,000-100,000 breeding pairs in Korea; c.10,000-100,000 breeding pairs and c.1,000-10,000 wintering individuals in Japan and c.100-100,000 breeding pairs and c.50-10,000 individuals on migration in Russia (Brazil 2009).
Trend Justification: This population is estimated to be declining on the basis of a decline in Japan during the 1980s and 1990s (Harris and Franklin 2000). |
