The Eurasian (or Northern) Sparrowhawk (Accipiter nisus) is a small bird of prey in the family Accipitridae which includes many other diurnal raptors such as eagles, buzzards, harriers, and other sparrowhawks. Adult male Eurasian Sparrowhawks have bluish grey upperparts and orange-barred underparts; females and juveniles are brown above with brown bars below. The male is up to 25% smaller than the female – one of the largest differences between the sexes in any bird species. Though it is a predator which specialises in catching woodland birds, the Eurasian Sparrowhawk can be found in any habitat and often hunts garden birds in towns and cities. Males tend to take smaller birds, including tits, finches, and sparrows; females catch primarily thrushes and starlings, but are capable of killing birds weighing 500 grams (18 oz) or more. Eurasian Sparrowhawks breed in suitable woodland of any type. This species is now one of the commonest birds of prey in Europe, although the population crashed after the Second World War. Organochlorine insecticides used to treat seeds before sowing built up in the bird population and the concentrations in Eurasian Sparrowhawks were enough to kill some outright and incapacitate others; affected birds laid eggs with fragile shells which broke during incubation.