The kererū (Hemiphaga novaeseelandiae), also called kūkū, kūkupa, wood pigeon or simply New Zealand pigeon, is endemic and one of Aotearoa New Zealand’s most valuable assets when it comes to native bush regeneration. It is one of our most iconic birds with its beautiful blue-green and white plumage. A bird that you often hear before you see, the noisy beat of its wings makes a distinctive sound as it flies from tree to tree.
The kererū is a large bird, measuring up to 510 mm from tail to beak and weighing on average 630 g, and is found throughout New Zealand.
Kererū are protected birds and endemic to New Zealand. Conservation efforts to restore the kererū’s habitat and increased pest control has helped to slow the decline in kererū numbers.
The kererū has the widest gape of all New Zealand native birds, which allows it to eat large berries. This makes them vital to our forest ecosystem, as trees such as karaka, miro, tawa and taraire rely on them for seed dispersal. Kererū are one of New Zealand’s keystone species, essential for the ongoing propagation of some of our native plant species.
The kererū is important in the seed dispersal of large native berries in forest ecosystems. Kererū are the only birds left (all others are now extinct) big enough to swallow the large fruits of the karaka tree.
Some seeds need to pass through the gut of a bird to properly germinate. With the extinction of the moa, kererū are the only seed dispersers with a bill big enough to swallow large fruit.
They have been called our “gardeners of the sky” due to their unique ability to disperse these large seeds.
Though the orange karaka berries are a major food source for kererū, the fresh kernels contain the alkaloid karakin, which is highly toxic to other animals. Dog owners have been warned to keep a close eye on their dogs to ensure they do not eat the berries, as this can be fatal. Our native species have evolved so that they can safely eat plants that others would find poisonous, for example, native bees are not harmed when they collect honeydew from tutu.
When fruit and flowers are not available, kererū will eat the leaves of trees such as kōwhai, tree lucerne, broom, willow, elm and poplar.
Occasionally, kererū gorge so heavily on ripe fruit that they become very full or drunk – as the fruit ferments inside them in the hot sun, they have been known to fall out of trees.
Kererū are monogamous and are often seen in pairs. In good conditions, they can live up to 21 years, but they are slow breeders with only one egg laid per clutch. In a good breeding season when there is lots of fruit available, they could raise three chicks, but in years where there is little to no fruit available, no eggs are laid. Eggs are usually laid between September and April with both parents sharing incubation.
Kererū are unusual in that they are one of only a few birds that produce crop milk to feed their chicks, it is a protein-rich milky secretion from the walls of the parents’ crops. When the chicks are a bit older this is combined with fruit pulp until it leaves the nest at about 40 days old.
Kererū are not fussy eaters – they browse on over a hundred native and 50 exotic, shrubs and trees. To help increase kererū numbers, plant kererū-friendly native plants in your garden such as rimu, ngaio, kōwhai, karaka, mataī, harakeke and rewarewa – a full list is on the Kererū Discovery website.