The controversy about whether the kea preys on sheep is long-running.
Sheep suffering from unusual wounds on their sides or loins were noticed by the mid-1860s, within a decade of sheep farmers moving into the high country.
Although some supposed the cause was a new disease, suspicion soon fell on the kea.
James MacDonald, head shepherd at Wanaka Station, witnessed a kea attacking a sheep in 1868, and similar accounts were widespread.
Prominent members of the scientific community accepted that kea attacked sheep, with Alfred Wallace citing this as an example of behavioural change in his 1889 book Darwinism.
Thomas Potts noted that attacks were most frequent during winter and snow-bound sheep with two years growth in their fleece were the most vulnerable, while newly-shorn sheep in warm weather were rarely molested.
Despite substantial anecdotal evidence of these attacks, others remained unconvinced, especially in later years.
For instance, in 1962, animal specialist J.R. Jackson concluded, while the bird may attack sick or injured sheep, especially if it mistook them for dead, it was not a significant predator.
In August 1992, however, its nocturnal assaults were captured on video, proving that at least some kea will attack and feed on healthy sheep.
The video confirmed what many scientists had long suspected: that the kea uses its powerful, curved beak and claws to rip through the layer of wool and eat the fat from the back of the animal.
Though the bird does not directly kill the sheep, death can result from infections or accidents suffered by animals when trying to escape.

Since Kea are now a protected species, their depredations are generally tolerated by sheep farmers, though why some Kea attack sheep, and others do not, remains unclear.
Various theories, including similarities with existing food sources, curiosity, entertainment, hunger, maggots as well as a progression from scavenging dead sheep and hides have all been put forward as to how the behaviour was first acquired.
Anecdotal evidence also suggests only particular birds have learned the behaviour, with identification and removal of those individuals being sufficient to control the problem.

There are also anecdotal reports of kea attacking rabbits, dogs, and even horses.
There are also suggestions that Kea used to feed on Moa in a similar way.
The controversy about whether the kea preys on sheep is long-running. Sheep suffering from unusual wounds on their sides or loins were noticed by the mid-1860s, within a decade of sheep farmers moving into the high country. Although some supposed the cause was a new disease, suspicion soon fell on the kea. James MacDonald, head shepherd at Wanaka Station, witnessed a kea attacking a sheep in 1868, and similar accounts were widespread. Prominent members of the scientific community accepted that kea attacked sheep, with Alfred Wallace citing this as an example of behavioural change in his 1889 book Darwinism. Thomas Potts noted that attacks were most frequent during winter and snow-bound sheep with two years growth in their fleece were the most vulnerable, while newly-shorn sheep in warm weather were rarely molested. Despite substantial anecdotal evidence of these attacks, others remained unconvinced, especially in later years. For instance, in 1962, animal specialist J.R. Jackson concluded, while the bird may attack sick or injured sheep, especially if it mistook them for dead, it was not a significant predator. In August 1992, however, its nocturnal assaults were captured on video, proving that at least some kea will attack and feed on healthy sheep. The video confirmed what many scientists had long suspected: that the kea uses its powerful, curved beak and claws to rip through the layer of wool and eat the fat from the back of the animal. Though the bird does not directly kill the sheep, death can result from infections or accidents suffered by animals when trying to escape.
Since Kea are now a protected species, their depredations are generally tolerated by sheep farmers, though why some Kea attack sheep, and others do not, remains unclear. Various theories, including similarities with existing food sources, curiosity, entertainment, hunger, maggots as well as a progression from scavenging dead sheep and hides have all been put forward as to how the behaviour was first acquired. Anecdotal evidence also suggests only particular birds have learned the behaviour, with identification and removal of those individuals being sufficient to control the problem.
There are also anecdotal reports of kea attacking rabbits, dogs, and even horses. There are also suggestions that Kea used to feed on Moa in a similar way.
Kea