Birds of prey are birds that hunt other birds and small animals. Today New Zealand has only three native birds of prey: the New Zealand falcon, the swamp harrier and the morepork.
The New Zealand falcon (Falco novaeseelandiae) and the swamp harrier (Circus approximans) are both daytime hunters. The morepork (Ninox novaeseelandiae) is a nocturnal hunting owl.
Since humans arrived in New Zealand, between 1250 and 1300 CE, several birds of prey have become extinct. The moa-hunting Haast’s eagle (Aquila moorei) was the world’s largest eagle, and had claws like a tiger’s. The large Eyles’s harrier (Circus eylesi), the laughing owl (Sceloglaux albifacies) and the New Zealand owlet-nightjar (Aegotheles novaezealandiae) are also extinct.
The German or little owl (Athene noctua) is not native. It was introduced early in the 20th century, and is common in eastern parts of the South Island and the Nelson region.
The barn owl is a rare vagrant from Australia that has bred in Northland.
The morepork, laughing owl and little owl are members of the owl order (Strigiformes), while falcons are Falconiformes and eagles and harriers are Accipitriformes. The three groups are not closely related, but share certain features. All hunt mostly from the air. They have acute vision, which helps them find prey. Some also have sensitive directional hearing. They have talons and curved bills for seizing prey – other birds, small mammals, lizards, frogs, and insects.
Super size predator
Haast’s eagle, now extinct, was the world’s largest eagle. Weighing around 12 kilos, it preyed on big birds, including 200-kilo moa, and died out when these were hunted to extinction. Haast’s eagle had humble origins. Its closest relatives are among the world’s smallest eagles, including Australia’s little eagle (Aquila morphnoides), which weighs just 1 kilo.
Other avian predators
Some other birds are at least partly predatory, even if they are not considered to be birds of prey. Many eat insects, worms, snails, frogs, lizards or small fish. Kea (Nestor notabilis), native mountain parrots, sometimes attack seabird chicks in their burrows. Weka (flightless rails, Gallirallus australis) take bird eggs and chicks from nests. So do black-backed gulls (Larus dominicanus), skuas (Catharacta lonnbergi) and non-native magpies (Gymnorhina tibicen). The 18-kilogram flightless adzebill (Aptornis defosser and A. otidformis), now extinct, apparently hunted other birds. All sea birds are marine predators – they catch and eat marine animals.