New Zealand Parrot - Ecology

Ecology

The isolated location of New Zealand has made it difficult for mammals to reach the island. This is reflected in the absence of land mammals other than bats. The main predators were birds: eagles (Eyles' Harrier, Kāhu and Haast's Eagle ), falcons (Kārearea) and owls (Whēkau and Ruru). Many of the adaptations found in the avifauna reflect the unique context in which they evolved. This unique balance was disrupted with the arrival of the Polynesians, who introduced the Polynesian rat and the Kurī (Polynesian dog) to the island. Later, Europeans introduced many more species, including large herbivores and mammalian predators.

The three extant species of this family occupy rather different ecological niches, a result of the phylogeographical dynamics of this family. The Kākāpō is a flightless, nocturnal species, well camouflaged to avoid the large diurnal birds of prey on the island, while the local owls are too small to prey on the Kākāpō at night. The Kākāpō is the only flightless bird in the world to use a lek-breeding system. Usually, they breed only every 3–5 years when certain podocarp trees like rimu (Dacrydium cupressinum) mast abundantly.

The Kea is well adapted to life at high altitudes, and they are regularly observed in the snow at ski resorts. As trees are absent in the alpine zone, they breed in hollows in the ground instead of in tree hollows like most parrot species.