The New Zealand falcon (Māori: kārearea or kāiaia; Falco novaeseelandiae) is New Zealand’s only falcon. Other common names for the bird are bush hawk and sparrow hawk. It is frequently mistaken for the larger and more common swamp harrier. It is the country’s most threatened bird of prey, with only around 3000 to 5000 breeding pairs remaining. The New Zealand falcon is slightly over half the size of the swamp harrier, which it usually attacks on sight. (Unlike the swamp harrier, the New Zealand falcon catches other birds in flight, and rarely eats carrion.) The male is about two-thirds the weight of the female.
An aggressive bird that displays great violence when defending its territory, the New Zealand falcon has been reported to attack dogs, as well as people.
The New Zealand falcon nests in a scrape in grassy soil or humus in various locations: under a rock on a steep slope or on a rock ledge, among epiphytic plants on a tree branch, or under a log or branch on the ground, or