Pest gun and trapper cage at Pukaha National Wildlife Centre with hen egg used as bait. PHOTO/KAREN COLTMAN
KAREN COLTMAN
[email protected]
Kiwi calls recorded during the Pukaha National Wildlife Centre survey resulted in pinpointing the location of at least 12 different kiwi, including pairs.
The 2018 census identified 18 wild kiwi in the Pukaha forest.
The ban on trapping during the first covid-19 lockdown was sited as a reason ferrets got into Pukaha National Wildlife Centre’s reserve and killed six tagged kiwis.
This disaster triggered management to launch an urgent kiwi count using specialist sonar tracking technology.
“After we discovered the loss of six out of only seven birds with radio tracking devices, we knew that there was a possibility that the toll could be higher and we had to find a way to conduct a census despite the cold wet weather and restrictions imposed due to covid-19,” Pukaha general manager Emily Court said.
Fifteen recorders programmed to detect kiwi calls recorded the elusive nocturnal bird. One recorder had about 1200 hours of recordings that were analysed by a specialised team in Auckland.
During the survey period, 52 North Island brown kiwi calls were recorded. This included 39 calls from males, 13 from females, and 10 duets [male-female pairs calling to each other].
These calls could be made by the same or different individual kiwis, so determining the exact number of kiwi present was not possible.
Young kiwi under two years old do not generally call so chicks born in the wild over the past few seasons were not detectable yet.
Court said, “confirmation that adult wild kiwis are paired in the forest, and likely to have been breeding, was a huge relief to all involved”.
“This would indicate that the wild population has been doing well and despite the devastating loss, the population has not dropped significantly.”
The reserve has had losses of wild birds to mustelid and feral cat attacks over the years but this year’s was stated to be an unusually high death count.
Pukaha had been boosting the wild population of kiwi in the region since 2005 and runs a hatchery breeding programme.
Not all kiwis released back into the wild are tagged but all are microchipped. Only the tagged ones can be tracked down relatively easily.
“We had such a great run, with very few losses for several years due to improving techniques and technologies and fantastic collaboration from neighbouring farmers and the regional councils,” Court said.
Twenty kilometres of ‘pest proof’ fencing, at a cost of around $20 million was unaffordable for the wildlife reserve and not fool-proof because it developed “leaks”, Court said.
“Conservation and working with wildlife has huge ups and downs, but we can’t give up, for the sake of the remaining birds and to honour all of those who have poured their hearts and souls into this project over the years. We need to do it for them.”
The only remaining tagged wild adult kiwi Kakama was detected to be on an egg this season.
On Wednesday, head ranger Jess Flamy and volunteer Serena Richdale retrieved the egg he was incubating and brought it into the hatchery. Evidentially a kiwi hatchling has a far greater chance of survival if is reared in a hatchery until it weighs 1.2kg.
The egg was due to hatch in nine days.
Kiwi pair Mapuna [Manukura’s white-feathered brother] and his mate Manawa have two eggs due to hatch in September.
