A small hawk that breeds in woods and even city parks in Japan.
Males are smaller than females, with red eyes and a faint reddish wash on the underside.
Between 1987 and 2005, a study of breeding Japanese Sparrowhawks in suburban Tokyo and Utsunomiya found different nest-tree patterns. In Tokyo, the birds began using trees other than Japanese red pine in the 1990s; during the 2000s they nested mainly in broad-leaved trees, with no pine nests after 2003. The early shift followed breeding expansion into small groves where pines were scarce. The authors suggested that later growth in Jungle Crow numbers may also have affected nest-site choice.
In Utsunomiya, pines remained plentiful in small groves and accounted for 66.7% of recorded nests in 1991–1994. The two cities therefore showed different nest-tree patterns as local breeding distribution and available trees changed.
Japan Ministry of the Environment Fifth Red List (birds) · Data Deficient (DD) for the Ryukyu subspecies only; no full-species category established here · Japan; subspecies Accipiter gularis iwasakii
Japan’s Ministry of the Environment Fifth Red List for birds lists the Ryukyu subspecies of the Japanese Sparrowhawk, Accipiter gularis iwasakii, as Data Deficient (DD). The list uses species or subspecies as its evaluation unit; this entry is for the subspecies. DD indicates that information for assigning an extinction-risk category is insufficient.