Predators & pests - Header Image

New Zealand, a land of birds, had no warm blooded mammal predators before people introduced them. These are now the main threat to kiwi’s survival – killing eggs, chicks and adults.

The main culprits are stoats and cats – which take a heavy toll on young birds during their first three months of life.

Dogs are particularly hard on adult birds and that’s bad for kiwi because these are the breeding birds – without them there are no eggs or chicks to keep the population stable or growing. Ferrets also kill adult kiwi.

Possums kill both adult kiwi and chicks, destroy eggs and steal kiwi burrows. And pigs destroy eggs and can also kill adult kiwi.

Other animal pests, such as hedgehogs, rodents and weasels, may not kill kiwi, but they also cause problems. First, they compete for the same food as kiwi. Second, they are prey for the same animals that attack kiwi, helping to keep the number of predators high.

Turning the tide

In areas where kiwi predators are intensively controlled, kiwi hatching increases to 50 – 60%. In order to sustain populations levels a 20% survival rate is needed, anything over that it grows. So management is making a difference, especially when dog owners keep their dogs under control.

Find out how Kiwis for kiwi are helping dog owners care for kiwi.

Mustelids - teaser image

Mustelids »

Stoats, ferrets and weasels are collectively known as mustelids.

Pigs - teaser image

Pigs »

Wild pigs are opportunist scavengers and foragers. Their omnivorous diet includes fern fronds and roots, supplejack, grasses, fruits, native snails, worms and centipedes – and the eggs and chicks of ground nesting birds.

Possums - teaser image

Possums »

Possums were introduced to New Zealand in 1837 in a deliberate attempt to establish a fur trade and ‘enrich’ New Zealand’s native biodiversity.

Rodents and Hedgehogs - teaser image

Rodents and Hedgehogs »

New Zealand has four species of rodent: kiore, Norway rat, ship rat and the house mouse. All were introduced. Kiore are regarded as a valued species (taonga) by some iwi.