KEY POINTS:
Twenty-eight rare kiwi eggs have been removed from the Okarito kiwi zone this spring, stunning the Department of Conservation, which collected three this time last year.
The Okarito brown kiwi, or rowi - the rarest species of kiwi - was considered to be on the brink of extinction with 300 birds left.
Three years ago, DoC began removing eggs from the South Westland forest to hatch in captivity, away from predators.
Last year, DoC staff retrieved three eggs for safe hatching at Willowbank in Christchurch and this year, of the 28 collected, 19 are waiting to hatch at Willowbank.
Biodiversity ranger Liz Brown said more birds were breeding earlier this year. "We are not sure why, possibly due to a fairly mild winter.
"The breeding season started in late July, and will probably run through until January or possibly February - plenty of time left for more eggs and chicks."
Four chicks have already hatched, four were unviable and possibly infertile from the start, and one was damaged by a predator.
Ms Brown said it had been an "incredible" start to the breeding season.
Staff were monitoring 35 new birds that were caught during winter and about 70 pairs now have transmitters, compared with 45 last year.
Okarito rowi feel soft to touch, whereas North Island brown kiwi feel quite coarse. The male and the female rowi take it in turns to look after the egg, while in most other kiwi species only the male does this.
In 2006, 12 chicks were successfully raised, in 2007 that rose to 23, and this year the kiwi team hoped for more than 30.
The birds have transmitters attached to their legs that send out a sequence of 15 distinct sets of beeps, picked up by receiver equipment carried around the forest by one of the kiwi rangers.
If the signal shows little movement, then it is likely the bird has lain an egg and is spending much of its time incubating.
- NZPA
