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 suspected to be 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.
There is very little data available on population size or trends for this species. Based on migratory concentrations and the size of the breeding range, Ferguson-Lees & Christie (2001) estimated the population to exceed 100,000 individuals. Large numbers have been counted on migration, including 53,575 at the Miyako islands, Japan in 1980 (Unpublished data, cited in DeCandido et al. 2004); c.32,000 in Japan in 1999 (Nitani 2000); and 14,962 in Thailand in 2003 (DeCandido 2004).
The population is suspected to be declining locally owing to ongoing persecution and loss and degradation of breeding and foraging habitats (Ferguson-Lees and Christie 2001). Declines have been recorded in Japan - the species was found on 28 survey units in the 1970s but none in the 1990s (Ueta et al. 2006). These declines have been linked to habitat loss as a result of abandonment or development of traditional paddy fields (Ueta et al. 2006), and a loss of prey due to modernisation of drainage systems (Fujita et al. 2015). The Russian population is also suspected to be undergoing a significant decline due to persecution along migration routes (Orta & Marks 2020). Declines in Northeast China have been linked to habitat loss caused by forest management for timber production and farmland reclamation (Deng et al. 2003).
Breeds in forests adjacent to open landscapes such as pastures, peat bogs, marshes, and paddyfields, where it finds most of its prey (Orta & Marks 2020). Wintering habitats include sugar cane fields, pastures and paddyfields (Orta & Marks 2020).
Loss of breeding habitat in forests in north-east China is attributed to agricultural development and timber harvesting (Deng et al. 2003). In Japan, many traditional paddy fields have been abandoned or developed for intensive agriculture, residential areas or industrial facilities, reducing the amount of suitable foraging habitat (Ueta et al. 2006). The modernisation of drainage systems in rice paddies has also reduced prey availability (Fujita et al. 2015). Up to 1,000 birds are shot annually on migration in Taiwan (China) (Orta and Marks 2020).
Conservation actions underway
The species is listed on CITES Appendix II, CMS Appendix II and Raptors MoU Category 2.
Conservation actions needed
In the absence of natural wetlands, traditional rice paddies are an important hunting ground for this species. Conventional rice farming is no longer economically viable, therefore incentives need to be introduced to encourage the maintenance of these habitats (Ueta et al. 2006).
Text account compilers
Symes, A., Ashpole, J, Harding, M., Ekstrom, J. & Butchart, S.
BirdLife International (2022) Species factsheet: Butastur indicus. Downloaded from http://www.birdlife.org on 03/07/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 03/07/2022.