The Kea

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These olive-green parrots are the largest surviving land-based flight-capable bird in New Zealand (45-50cm head-tail length, 700-1000g weight). The “clowns of the mountains” live exclusively on the South Island of New Zealand mainly along the alpine ridge in association with southern beech (Nothofagus) forests. Kea may also be found in the alpine grassland and a small population can also be found in the West Coast forests. Although they can be found at sea-level (West Coast), they are one of the few Psittaciformes (parrots) in the world to mainly inhabit alpine regions, and the only one to do so in winter conditions.

These parrots are omnivorous opportunists that are known to feed off of more than 100 different species of plant, from many of which only parts are eaten e.g. the roots extracted from the ground. Their propensity to seek out new food sources, together with a high level of opportunism and scavenging/hunting behaviour meant that sheep kept in the highlands of the Southern Alps were seen as potential food sources. Vastly exaggerated numbers of sheep lost to kea in the 19th century caused the government to support the culling of the species, and led to more than 150.000 kea being killed, before they gained protective status in 1986. Current population estimates range from 2000-5000 kea still left in the wild.

They live in a fission/fusion like social organization and exhibit an extended period of adolescence (3-7 years) before forming live-long pairs. Kea breed in natural underground burrows, where the female will lay 4 eggs. Brooding, nest care and feeding of the chicks are performed exclusively by the female, with the male foraging for food, arriving intermittently to feed the female at the entrance of the nest. 3 months after hatching the chicks fledge, and together with the parents they will often gather at common social spots with groups of juveniles and sub-adults as well as other families. Most of the kea’s unique behaviours result from the complex social interactions that dominate their daily activities at these sites, such as group foraging and play.

Several factors make the kea an ideal species for cognition and behaviour research. The kea is highly neophilic, most likely due to the low predation risk during their evolutionary history in New Zealand, and approaches novel objects/setups with an immediate curiosity unmatched in the avian world. The long juvenile phase and high life expectancy (up to 40 years) are both factors believed to allow for an increased selection of higher cognitive flexibility and increased social learning, while their foraging ecology makes the kea a highly explorative species. Lastly, the constant changing of group composition has allowed the kea to evolve a large capacity for tolerant social interactions, not the least of which is their extensive play behaviour (possibly the most complex of any bird).

 

Kea Conservation Trust 2

 

 

Kea Lab