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). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size may be moderately small to large, 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.
Status and trends of the population are very poorly known. An average of 14,320 (minimum: 5,452 , maximum: 28,254 ) Japanese Sparrowhawks were counted migrating over Khao Dinsor, Thailand between 2010 and 2016. The population is roughly estimated to number in the tens of thousands to 100,000 individuals, based primarily on counts of migrants in Indonesia (Ferguson-Lees and Christie 2001). Assuming a total of 20,000-100,000 individuals, the number of mature individuals is 13,400-67,000.
The population is suspected to be stable in the absence of evidence for any declines or substantial threats.
Breeds from southern Siberia and northern Mongolia to eastern China, Korea and Japan. Winters in Southeast Asia, from south-east China to Indonesia and the Philippines (Orta and Marks 2020).
Behaviour Mainly migratory, but sedentary in South Ryukyu islands. Autumn migration is from August to November, spring migration typically from March to May (Orta and Marks 2020). Habitat The species nests in deciduous, coniferous and mixed forest and riparian woodland. The iwasakii subspecies inhabits evergreen subtropical forest. Less restricted to forest outside the breeding season. It occurs along forest edges and in a variety of semi-open landscapes where open areas are interspersed with tree cover, including agricultural and marshland (Ferguson-Lees and Christie 2001). Avoids closed-canopy forest and plantation monocultures. Hunts along forest edges and in clearings. Diet Mostly small forest passerines, occasionally medium-sized birds, small mammals, reptiles and insects. Breeding Small nest made from twigs and lined with green foliage and bark built in a tree up to 10 m above ground. In Japan, the species prefers to nest in Japanese red pines (Pinus densiflora) (Ueta 1997).
Land-use change within the species's wintering range could result in a loss of roosting habitat (Germi et al. 2009). For instance logging operations in Bali may reduce the availability of roost sites (Germi 2005). The preferred tree species for nesting (Japanese Red Pine Pinus densiflora), in which nesting attempts are particularly successful (Ueta 1997), appears to be in decline due to air pollution (Kume et al. 2000), which may lead to a decline in sparrowhawk numbers. An increase in the population of Large-billed Crow Corvus macrorhynchos may be reducing breeding success in some areas (Ueta and Hirano 2006). Capture of birds from migratory roost sites for trade is unlikely to be significant (Germi and Waluyo 2006). Trade at wintering grounds in Indonesia also appears to be at a low level, and is unlikely to be causing significant declines (Iqbal 2016, Gunawan et al. 2017).
Conservation actions underway
Listed on CITES Appendix II, CMS Appendix II and Raptors MoU Category 3.
Conservation actions proposed
Population status and trends of this species are poorly understood, partly due to difficulty with identification, therefore it would benefit from further population monitoring throughout its range.
Text account compilers
Butchart, S., Ekstrom, J. & Ashpole, J
BirdLife International (2023) Species factsheet: Accipiter gularis. Downloaded from http://datazone.birdlife.org/species/factsheet/japanese-sparrowhawk-accipiter-gularis on 29/05/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://datazone.birdlife.org on 29/05/2023.