Story: Birds of prey
Page 3 – New Zealand falcon
Swooping down on their prey at speeds of up to 200 kilometres per hour, New Zealand falcons are supreme aerial hunters. The falcon (karearea, Falco novaeseelandiae) almost always takes live prey on the wing, catching it with sharp talons. The fearless bird will attack and kill animals larger than itself.
Habitat and distribution
New Zealand falcons vary in size and colour according to their main habitat. The bush falcon (whose population is an estimated 650 pairs) is found in the North Island and the west and north-west South Island. The South Island’s eastern falcon (3,150 pairs) is found in open country. It is larger, and paler in colour. The southern falcon (200 pairs) lives in coastal Fiordland and the Auckland Islands, and has more reddish plumage.
These population figures are from a 1978 study, but numbers have probably fallen since. The World Conservation Union classifies the falcon as a near-threatened species. It is threatened by introduced predators such as stoats, by changes in habitat, and by people who shoot it illegally.
New Zealand falcons are not big birds, so their hunting feats are all the more impressive. At 500 grams and 45 centimetres, the female is larger than the male (300 grams). Females can kill young rabbits or hares weighing up to 3 kilograms.
Falcons also take large birds such as white-faced herons, kererū (New Zealand pigeons), ducks and pheasants. They catch big insects such as grasshoppers and beetles.
Falcons’ wings are angled back like an arrow. An attacking falcon dives steeply, giving what ornithologist Walter Buller described as a ‘shrill cry of terror’ when it seizes its victim. After it catches a bird, it takes it to a plucking post, and dislocates the bird’s neck using a special notched tooth that all falcons have. It then plucks the feathers and eats the entire bird.
Courtship and breeding
Food plays an important role in falcon courtship. The courtship starts in early spring, when the male chases the female and pretends to attack her. This is followed by aerial acrobatics. The bond is sealed when the male carries prey to the female. She chases him, and he offers her the food near their future nest site.
Between September and December the female lays up to four reddish brown eggs. Falcons nest in a simple scraped hollow on a sheltered cliff ledge, in an astelia epiphyte high in a tree, or on the ground under a log or bush. They fiercely defend the surrounding area, and may dive-bomb passers-by. Male and female both incubate the eggs, for 33–35 days in total. Juvenile falcons can fly at around 35 days and may be independent of their parents after three months.
Friends of the vine
Marlborough wine growers are hoping that falcons will help rid their vineyards of pest birds that eat or damage grapes. The growers are supporting a breeding programme to re-establish the falcons among vineyards on the Wairau Plains.
Groups including the Wingspan Birds of Prey Trust, the Raptor Association of New Zealand and the Department of Conservation are joining forces to save falcons. They have raised falcons in captivity and released them into the wild.