There is one natural population of about 450 rowi (Apteryx rowi) in Ōkarito forest and surrounds in South Westland. Ōkarito was designated as one of the five special Kiwi Sanctuaries in 2000. Rowi can also be found on two predator-free islands in the Marlborough Sounds, following successful translocations of birds.
Unlike some other kiwi species, male and female rowi both take turns incubating their eggs. Although they do not rely on their parents for food and protection (all kiwi chicks are self-sufficient as soon as they hatch), rowi juveniles often stay with their family group for years.
Rowi are slow breeders, normally laying just one egg per year – making the death of an adult bird all the more devastating to the population.
Operation Nest Egg
The biggest threat to rowi survival is stoats. Trapping failed to stop the stoats and rowi numbers were declining quickly. With the support of Kiwis for Kiwi, DOC established Operation Nest Egg.
Operation Nest Egg involves removing eggs from the risk of predation, hatching them in captivity, and placing the chicks in a predatorfree environment until they are big enough to fend for themselves (between 1 to 1.2 kg). They are then returned to the wild.
Unmanaged, a tiny proportion of kiwi eggs produce an adult bird.
Roughly 80 rowi eggs are laid each season, 40 of these eggs fail to even hatch. Of the remaining 40, 28 are killed by stoats, and about 8 die of natural causes or killed by predators. This leaves just 4 chicks alive after the first 6 months Of these 4 chicks, only 2 will survive over 1 year to make it to adulthood.
However, using Operation Nest Egg the number of birds to make it to adulthood rises from 2 to approximately 50 per season. The aim is to increase the rowi population to 600 birds by 2018.
Using the latest monitoring technology, we can keep a close eye on rowi. DOC has worked with a private business to develop ground-breaking technology specifically for our kiwi conservation work.
To track rowi, transmitters are attached to their legs. By measuring the bird’s activity, these intelligent transmitters tell us where the bird is, when an egg is laid and when a chick hatches.
A system for data collection (nicknamed ‘Sky Ranger’) means that transmitter signals, that would previously have taken 45 days of groundwork to complete, can now be gathered during a two-hour flight.
Franz Josef Glacier Base
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13 State Highway 6
Franz Josef Glacier 7856
PO Box 14
Franz Josef Glacier 7856