Kererū flies in for a feast of foliage

For a period of about three weeks, we had an unusual situation at our place. A kererū, New Zealand pigeon, spent several hours each day sitting on top of a metal frame next to the workshop door, just under the roof overhang.

From that position it launched itself on to flimsy branches of a self-sown tagasaste/tree lucerne nearby. This 2m tall tree was destined for the chop because it is unsuitable in that position. Meanwhile, the kererū gobbled all the fresh tender leaves and flower buds of each branch, often hanging upside down because the branches were quite thin for a bird that weighs about 650g. The shape of the tree changed considerably from a more upright to an almost pendulous branch structure. It is now twice as wide as it was before the regular visit by the kererū and has less than 50% of foliage. The kererū in question is now most days round the back in a totara. We do have many other tagasaste on the property and we will watch with interest whether the bird returns to this site before we chop the tree down.

To avoid any disturbance while the bird was either in the tree or on top of the metal frame, we had to plan our visits to the workshop during daylight hours.

This bird did not only gorge itself on the foliage it also appeared to be obsessed watching its reflection in the windows. Was it watching itself or did it think there was a mate on the inside of the glass? It certainly happened repeatedly that the bird was clinging on to the window frame and tapping on the glass with its beak.

We have two species of native pigeon, the New Zealand and the Chatham Island pigeon or parea. The latter is about 20% heavier than the kererū.

Now that moa are extinct, kererū and parea are the only bird species that can swallow large fruit with their extra wide beaks, which is important for seed dispersal of some of our New Zealand native plants which bear large fruit such as karaka, miro, tawa and taraire. These native plants do not appear locally. Instead, the kererū in our region are partial to the fruit of many space invaders, cherry, plums, laurel and so on, much to the chagrin of all the caretakers of native ecosystems.

According to research, possums, rats, stoats and cats eat the egg in the nest of the pigeons and also the fledgling. Cats and stoats are also known to attack adult birds. Pest control is, therefore, an important task to ensure the population does not decline. Everyone enjoys seeing and hearing these majestic birds.

On Banks Peninsula tagasaste are being removed on the road verges as there are too many casualties of kererū when they take off and collide with vehicles.

Five-finger, pate (seven-finger), fuchsia, kahikatea, kōwhai, coprosma and wineberry provide an important food source for kereru in our region. They disperse seeds like other birds, which is the most efficient way to naturally regenerate native vegetation.

• Ines Stager is a landscape architect based in Geraldine, and a committee member of the local branch of the Royal Forest & Bird Protection Society