There is one natural population of about 350 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.
Rowi vary from other species of kiwi in a range of ways. They are quite greyish in colour and often have patches of white on their faces. They also feel much softer to touch than other kiwi whose feathers are quite coarse. Both the male and female rowi take it in turns to look after the egg, and they also have a longer lifespan.
Despite predator trapping the biggest threat to rowi survival are stoats as they continue to kill a high percentage of kiwi chicks, until the chicks are approximately one kilogram in weight and better able to defend themselves.
Rowi are the rarest of the world’s five species of kiwi. This title unfortunately earns them a place on the ‘nationally critical’ list.
Kiwi under threat from pests
Two hundred years ago millions of kiwi lived throughout New Zealand’s forests. Now, introduced pests are so numerous that without extensive management they would ultimately lead to the demise of our national bird.
The biggest threat to rowi survival is stoats. They are wanton killers; able to prey on species four to five times heavier than themselves. Despite the use of 3000 traps in Ōkārito forest from 2001 to 2006, stoats continued to kill a high percentage of rowi chicks.
Dogs find the strong distinctive scent of kiwi irresistible and easy to track. With no wing muscles to protect its chest, a kiwi is crushed to death within seconds. Just one uncontrolled dog can devastate an entire kiwi population. Keep dogs and cats away from kiwi zones.
Possums kill kiwi, destroy eggs and compete with kiwi for burrows.
Rat numbers can dramatically increase, ravaging populations of nesting songbirds. They also eat invertebrates - vital kiwi food.
BNZ Operation Nest Egg
Trapping failed to stop the stoats. Rowi numbers were declining quickly so something had to be done. With the support of BNZ Kiwis for Kiwi, the Department of Conservation established BNZ Operation Nest Egg.
BNZ 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 at the jaws and claws of other 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 BNZ Operation Nest Egg the number of birds to make it to adulthood rises from 2 to approximately 34 per season. The aim is to increase the rowi population to 600 birds by 2018.
Using the latest monitoring technology, the DOC team can keep a close eye on rowi. DOC has worked with private business to develop ground-breaking technology specifically for DOC’s kiwi conservation work.
In order to track rowi, transmitters are attached to their legs. By measuring the bird’s activity, these intelligent transmitters tell the DOC team where the bird is, when an egg is laid and when a chick hatches.
A new 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.
How you can help kiwi
- Dogs are strictly prohibited in kiwi sanctuaries. Make sure you know where your dog is at all times. Report any dogs seen in kiwi sanctuaries to DOC.
- Do not release unwanted cats or ferrets into the wild. They will kill kiwi and other birds.
- Keep your speed down.
- Watch out for birds on roads when travelling near a kiwi sanctuary after dark.
- Get involved. Join a local kiwi conservation project or start one yourself. See Rowi and Tokoeka Kiwi Project volunteers.
- Make a donation. Visit Kiwis for Kiwi.
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200th rowi kiwi returned to the wild - 9 November 2013
The return of 12 juvenile rowi kiwi to the Ōkārito Kiwi Sanctuary today includes the 200th of this rare species to be raised through the successful BNZ Operation Nest Egg programme.
Rowi chick success on Blumine Island - Conservation Blog 29 May 2013
See a photo of a kiwid dog checking two new rowi parents.
Return of kiwi to North Island after hundreds of years absence - 18 June 2012
Twenty juvenile rowi will be going to Mana Island, near Wellington, to establish a new colony in the hope of improving the breeding prospects for the species. Normally they would be going home to Ōkārito, in South Westland, from their crèche on Motuara Island in Queen Charlotte Sound.