The threat posed by rats, stoats and possums to our bird species is "significant and urgent" and the battle continues to quietly rage in forests large and small around the greater Wellington region.
Over the past decade hundreds of tonnes of the controversial poison bait 1080 have been dropped in the Tararua, Aorangi and Remutaka ranges in an effort to push back a tide of pests, but the advent of new technology is making ground trapping a more attractive option.
DOC's director of operations for the Lower North Island area Reg Kemper said doing nothing is not an option.
"We have to take action to protect our most vulnerable native species. Biodegradable 1080 is the most effective tool we currently have," he said.
As well as Project Kākā, DOC also supports the Pukaha Mt Bruce Restoration project near Eketahuna and collaborates with OSPRI which conducts large scale pest control operations in Aorangi Forest Park in the south east corner of Wairarapa as part of its bovine tuberculosis (TB) eradication programme.
DOC has spent $1.68 million on aerial drops in the Tararuas since 2010 and OSPRI spends $4-5ma year on its Lower North Island operations.
More than 100 tonnes of 1080 has been dropped as part of Project Kākā and was spread over the 2010, 2013 and 2016-17 operations.
DOC's ultimate goal was to maintain and restore the diversity of our natural heritage, Kemper said.
"If sustained pest control can be achieved, it may be possible to reintroduce locally extinct birds including robins, whio (blue duck) and kiwi."
Aorangi Restoration Trust spokesman David Lawrence said many forest users had noticed a resurgence in birds but rat populations could bounce back in a matter of months after 1080 drops.
"You hear people say that the birdlife has never been so marvellous and I think the 1080 is timed to be strategic for the hatching of birds.
"1080 is really fire-fighting. It's not necessarily making progress in the long term, but it certainly holds things where they are, but how many years can we go on using it?"
Martinborough fisherman and author Bill Benfield is vehemently opposed to the use of 1080, the reasons for which are outlined in his book At War With Nature calling the use of aerial poisoning a "rort" promoted by the pest eradication industry.
He argues that the use of 1080 is based on the false premise that possums are a threat to native birds.
"1080 kills every living thing on a non-discriminatory basis - possums, rats, birds (native and non-native), insects, worms, bees, fish, butterflies."
This contrasted to Dave Hansford's widely-circulated book Protecting Paradise which examines anti-1080 arguments and "finds conclusively that the many claims made by 1080 opponents are plain wrong".
"After more than 60 years of research into 1080, there remains no evidence that it persists in the human food chain, or causes cancer, or harms our waterways," Hansford said.
Victoria University researcher Stephen Hartley has been monitoring pest and bird population numbers in Aorangi Forest Park which shows clear evidence that pest numbers plummet immediately after a 1080 drop but bird populations remain relatively unaffected.
Although 1080 would kill any animal that consumed enough of it, the type of cereal bait now used meant it was usually eaten by target animals such as rats, possums and stoats.
The university monitoring showed birds such as the bellbird, the tomtit, rifleman and whitehead made a comeback while pests were suppressed.
Hartley admitted that rat populations were quick to recover and could be back to pre-bait drop levels within 6-18 months, depending on conditions.
The use of 1080 is also supported by organisations such as Greater Wellington Regional Council, Federated Farmers and Forest & Bird.
Phasing out 1080 with smarter trappingAlthough 1080 is the pest control tool of choice in larger forests, smaller blocks are leaning more heavily on sophisticated trapping systems and strategic planning.
Pukaha Mount Bruce National Wildlife Centre forest restoration project began in April 2001 with the aim of restoring the area of remnant indigenous forest just south of Eketahuna.
Pukaha chairman Bob Francis said with the implementation of new strategies and the installation of hundreds of auto-resetting Good Nature traps they were moving away from 1080.
From a sustainability and credibility point of view, they would prefer to be able to keep their forest pest free without 1080.
Pukaha gets 35,000 visitors a year and its star attraction is the white kiwi Manukura. The unfenced forest is now home to 80 kōkako and more than 300 kākā. It is hoped the kākā populations at Pukaha and on Kapiti Island will help sustain and grow fragile populations in the Tararua Ranges.
The Department of Conservation's involvement at Pukaha has reduced in recent years, but the Government still provides $200,000 a year which goes towards the centre's captive breeding programmes.
The Pukaha Mt Bruce Trust spends $150,000-200,000 a year on trapping and poisoning to keep pests down in the 942ha forest. This money is generated by fundraising and charitable grants. The Greater Wellington Regional Council provides pest control for another 2500ha buffer zone around the reserve.
- $1.34m spent on Project Kākā 1080 drops since 2010.
- 95 tonnes of bait dropped in Project Kākā over 29,000 hectares
- $70m spent in total every year across NZ on pest control
- $28m pledged in 2017 from Government on Battle For Our Birds over four years
- 900,000 hectares covered in Battle For Our Birds
- Millions spent every year to eradicate TBIn terms of scale and cost, OSPRI's TB control operations in the Greater Wellington area are considerably larger than anything the Department of Conservation is undertaking.
- On average, $4-5 million a year over the past 10 years has been spent on all operational activities in its Southern North Island Vector Risk Area with 158,870ha of farmland declared free of TB.
OSPRI spokesman Oliver Bates said controlling pests was vital to eradicate TB.
"Pests like possums and ferrets carry TB and can pass it on to cattle and deer. Possums are the main transmitters of TB (also known as a vector) which is why we focus our pest control on them.
"They are responsible for around half of all new herd infections. If possum numbers are reduced to below two possums per 10 hectares for a number of years, the disease will eventually die out," he said.
There have been 1080 drops on more than 100,000ha in the area in the past 10 years and 450,000ha has ongoing ground control. OSPRI plans another 106,000ha of aerial drops as part of its long-term plan to eradicate TB.
OSPRI credits pest control for dramatically reducing the number of infected herds in the Wellington region from a high of 380 infected herds in the mid-1990s to just two today.
The TBfree programme is funded through a government-industry partnership. Its current plan aims to eradicate bovine tuberculosis (TB) from New Zealand by 2055. They want to have no TB in cattle and deer herds by 2026 and eradicate the disease from possums by 2040.
OSPRI collaborates with DOC on conservation land and they work with organisations such as Aorangi Restoration Trust and Victoria University, which have conservation projects in these areas.
Read the full article here: https://www.stuff.co.nz/environment/95829775/are-we-winning-the-battle-for-our-birds