In the North Island there is only one kind of kiwi, the North Island brown kiwi, but it is divided into four closely related sub-races; ‘Eastern’ (Bay of Plenty, Hawkes Bay), ‘Western’ (Taranaki, Wanganui, King Country and Tongariro), ‘Coromandel’ (Coromandel Peninsula), and ‘Northland’ (Whangarei to Cape Reinga).
The kiwi living in the Ruapehu Region are the western race of the North Island brown kiwi (Apteryx mantelli), and are classified as in Serious Decline.
There are just enough of each sub-race to allow conservation managers to keep them separate, avoiding interbreeding of the races to maintain the unique genetic biodiversity.
Kiwi live in native forests, exotic forests, scrub lands and rough pasture. They are strongly territorial and are often aggressive toward unwanted intruders.
Kiwi roost during the day, either under the ground in burrows or under dense vegetation, windrows or thick scrub including toitoi, crown fern and dead ponga fronds. An individual bird may have as many as 40 “campsites” within its territory and usually roosts in a different location each day. The exception is when the male kiwi is incubating eggs.
Kiwi eat worms, spiders, insects, freshwater crayfish, berries and seeds throughout the stages of their lives. Their exceptional sense of smell means they can detect food easily from leaf litter, rotting logs and soft soil. Their bill often leaves characteristic probe holes. Kiwi feed at night and often traverse their whole territory (20-30ha) in search of food.
Kiwi are generally monogamous and mate for life, which may be up to 35 years. The female is 20 to 30 % larger than the male and after she has laid the eggs she leaves the male to do the incubating.
Kiwis begin to breed at around 2-4 years old. Usually two clutches of two eggs are laid, and in each clutch the eggs are laid 20-30 days apart. Once the second egg is laid the male begins incubation, which takes around 80 days. Sometimes a third clutch is laid, and sometimes three eggs are laid.
The nesting burrow is usually lined with an untidy array of soft leaves, grass and moss then lined with feathers. When inside, kiwi often pull leaves and sticks across the entrance as camouflage and to retain heat and moisture.
April and June– birds come together to mate and maximum calling takes place
June/July– first clutch of two eggs laid in a nesting burrow
July to September– the male incubates the eggs for up to 80 days until the chicks hatch.
September/October– Chicks hatch. After a few days they are moving around and foraging on their own – under the watchful eye of the male.
October/November – possible second clutch of two eggs in a different nesting burrow.
January and February– second clutch of chicks hatch.