Through an intensive 10 year pest control and monitoring programme, DOC and other organisations and volunteers are working together to target species that are the biggest threat to native bird life and forest systems.
The project is named for the iconic native parrot the kākā, plentiful on nearby Kapiti Island and at Pukaha Mount Bruce, and representative of the many species that are expected to become more abundant as a result of this programme.
This initiative began in 2009 and covers a 29,801 ha area from Otaki Forks to Holdsworth campground. View map of Project Kaka zone (PDF, 776K).
The Project Kāka zone covers the most used areas of the park, so that as many people as possible will experience the expected improvement in forest health and increase in bird life. It includes a diverse range of forest types including fertile river valleys and higher altitude beech, kāmahi and fuchsia forests.
Battle for our Birds
In autumn 2017 Project Kākā plans to carry out predator control in the park to restore native forest bird, insect and plant communities. Without predator control, species such as kākā, korimako/bellbird and kākāriki are likely to suffer heavy losses.
DOC, other organisations and volunteers are working together to target the biggest threats to native bird life and forest systems through an intensive 10-year pest control and monitoring programme.
2014 pest control works
Intensive monitoring by DOC, the Animal Health Board, Landcare Research and Greater Wellington Regional Council has shown significant drops in pest numbers after each 1080 operation and increasing populations of native bird species. Within the Project Kākā treatment area, counts of native birds (eg, bellbird, kākāriki, rifleman, tūī and whitehead) have shown increased numbers.
However, during years when there has been a high beech tree seedfall, increases in predator numbers have occurred with an associated decline in the numbers of some vulnerable native birds.1080 operations are best timed to coincide with high beech tree seedfall events when predator population growth is high.
Results from DOC’s 2014 Battle for our Birds programme in the South Island showed the nesting success of robin and riflemen was significantly higher within pest control areas than outside.
2017 the battle continues
Extensive beech seeding, as occurred in 2014, is occurring again in 2017. Rimu and hīnau trees may also seed prolifically in some forests and cause rises in predator numbers that need to be managed.
Effect of pests on native species
- Possums are mainly vegetarians, but eat the flowers, fruits and leaves of plants that are key food sources for many native birds and invertebrates. They also eat bird eggs and fledglings, as well as invertebrates.
- Stoats are a key predator of many birds, particularly when they're nesting as they eat the eggs.
- Rats are also a constant source of predation, especially for the smaller forest birds such as bellbirds, robins, riflemen and fantails.
About the project
1080 bait pellets are distributed by GPS-guided helicopter throughout the operational area (see map) in spring every 3 years, starting in 2010.
Project Kākā is also intensively monitoring changes in the adjacent forest areas over a 10 year period and comparing them to changes in the Project Kākā zone to learn more about how to improve pest management in the park.
1080 is an effective toxin for pests such as possums, rats and stoats and is particularly suited because the area to be treated in this operation covers a huge landscape of remote and rugged terrain, making ground control impractical. It is estimated that controlling possums alone, using ground control, would cost at least 3 times as much and would leave many areas untreated.
The use of GPS technology in helicopters allows for even coverage of bait and accurate placing of 1080 within the operational area boundaries, avoiding sensitive areas such as huts or water intakes. Overall, this results in better pest management and less risk to visitors to the area.
1080 is biodegradable so does not accumulate in the environment or persist in soil or water. In favourable conditions, soil micro organisms break down 1080 in about two weeks.
Intensive monitoring undertaken by DOC, TBfree New Zealand, Landcare Research and Greater Wellington Regional Council since Project Kākā was initiated has shown significant drops in pest numbers and increasing populations of some native bird species.
Counts of riflemen, whiteheads and kākāriki increased following the first 1080 operation in 2010, compared to the non-treatment area where no 1080 was applied. These species are able to breed quickly but are also very vulnerable to predation. They can give us an early indication if pest control is working.
Progress report to 2013 (PDF, 1,005K)
This report summarises the results of Project Kākā pest animal and bird monitoring programmes between 2009 and 2013.
Project background and progress report 2010–2011 report (PDF, 5330K)
The report outlines the rationale for Project Kākā, and summarises the results of activities over the first two years – 2010 and 2011.
As we collect more data over the 10 year term of the project, the effect of 1080 on forest birds and pest animals in Tararua Forest Park will become clearer. We may also start to see positive changes in bird counts for slower breeding species, such as kākā, which is likely to be boosted by the arrival of birds from nearby strongholds on Kapiti Island and at Pukaha Mount Bruce.
If sustained pest control can be achieved, it may be possible to reintroduce locally extinct birds including robins, whio (blue duck) and kiwi.
The same method is being used to monitor weta numbers (though not a pest species!). Deer densities are being assessed based on faecal pellet counts.
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