KEY POINTS:
Tracking devices helping rangers keep tabs on Northland's endangered kiwi population have brought the devastating news that up to 70 of the birds may have been killed by dogs.
The slaughter took place during the past fortnight at Purua scenic reserve, north of Whangarei.
Department of Conservation kiwi ranger Pete Graham said DoC came to the sad realisation the northern brown kiwi were dead after being alerted by tracking transmitters which send a different signal when the birds die.
"If the kiwi stays still for more than 18 hours, the signal speeds up. After tuning in, the workers heard a whole heap of fast beeps ... the more they checked the more dead kiwi they found."
Seven birds with transmitters were found lifeless, Mr Graham said, and they made up only 10 to 20 per cent of total kiwi numbers in the reserve.
"It's inconceivable the dogs only took birds with transmitters, so if you extrapolate, that means between 35 and 70 birds were killed. The dead included breeding birds which will have a huge impact ..."
The deaths would set the sanctuary back six years, he said.
The 70ha block at Purua reserve became a kiwi sanctuary in 2000. It was chosen because of its high density of kiwi.
It has been part of the "operation nest egg" breeding programme to increase kiwi numbers in the wild.
It took three to four years for kiwi to reach breeding age, and their life expectancy was 50 to 60 years.
But the average age of kiwi in Northland was only 13 years.
The reason the birds died so young was uncontrolled, untrained dogs, Mr Graham said.
He said all Northlanders should think about how special it was to have kiwi in their backyard.
- NZPA