Monitoring & Trapping Results

Experience in New Zealand has shown that it is possible to see a 50% compounding increase in birdlife every year. The Trust is motivated toward achieving this goal. Due to its size and maturity, Puketi Forest provides good wildlife habitat for a variety of species not currently in the forest, but found there historically. This means that future translocations could be successful. Our next step after our pest eradication strategy is complete will be to develop reintroduction strategies for specific species. We'll keep you posted on our progress. Visit this page to stay up to date on our monitoring and trapping results.

Early Battle Won in Fight for Kiwi Survival

The Trust is pleased to announce that after three years of intensive pest control, this year's counts have indicated an increase in kiwi numbers in the forest. This means that the population has been rising steadily since trapping began in 2003, and considerably since call counts were conducted in 2000.

As outlined in the table below, calls were monitored at ten locations. At two locations, Bramleys Ridge and Walnut/Pirau Road, the number of birds calling increased by at least 50%; from 4 to 8 and from 1 to 5, respectively. At all other locations but two, the number of birds calling stayed the same or increased slightly. Calls counted at Takapau/Pirau Road and Rain-gauge indicated slight drops in kiwi numbers (click to enlarge table below).

Although stoats are the main predator, the Trust attributes this increase in numbers in part to effective rat control. Rats are not a kiwi predator but a competitor; the invertebrate diet of rats and kiwi is almost identical. To date the Trust has eradicated 2415 rats from Puketi Forest and is two thirds of the way toward achieving its rat control goals.

Tracking tunnels are used to monitor rats, stoats and mustelids (stoats, weasels and ferrets). By observing the footprints of the animals passing over the inkpad in the tunnel, an index of abundance can be obtained. The Trust's pest eradication goals are to keep the numbers of rats below 5% in the tracking tunnels. Rat numbers have been reduced from 100% in April 2005 to 13.5% in April 2006. This shows that rat numbers are down, while bird numbers have increased. The Trust is currently seeking funding to expand its core rat control area from just under 400 to 600 hectares.

Without predator control only 10% of young kiwi reach 6 months. This figure increases to more than 60% in trapped areas. The Trust believes that intensive pest control has resulted in higher survival rates for young kiwi chicks, which are too young to call this year but should be calling by the time they are 3 to 4 years old.

Northland has more remnant populations of kiwi than anywhere else in New Zealand. Between the years 2000 and 2004 before the Trust began trapping, kiwi numbers dropped by 55%. Without concentrated pest control, kiwis would become extinct in 25 years in Puketi Forest.

The kiwi population on the mainland will decline without predator control. With predator control over large areas, kiwi can survive. If the Trust attains the level of funding it needs to continue its trapping programme, numbers of the threatened North Island Brown Kiwi will increase, ensuring that this population survives long term.

Many thanks to those volunteers who spent cold nights in the forest counting kiwi calls.

Bird Counts Show an Increase of 85%!

The Trust's vision is becoming a reality as Ian Wilson, Trustee conducted bird counts forest in late April and discovered to his absolute delight that bird populations are increasing—some species by as much as 433%!

Says Wilson, "I was as excited as a young child on Christmas morning, as at site after site I was surrounded by birds—sometimes over a dozen would be moving through the sub-canopy with others calling from further away."

Even though the Puketi Forest Trust has been targeting rats for only five months in a 350 ha. area of Puketi Forest, the total number of birds recorded from the eight bird count locations in this core area has increased from 53 last autumn to 98 this autumn—an increase of 85%.

The four previous counts (three completed before rat trapping and one, a month after it began) were remarkably consistent, with counts ranging from 51-53 birds. Even though the Trust's rat trapper, Clint Sturge, observed a lot more fantails, the Trust was quite unprepared for the massive increase in fantail numbers recorded. An increase from 3 last autumn to 16 this autumn (433%) highlights the impact rats have on native birds. The other species to show a big increase were silvereyes, increasing from 10 to 26 (160%). These two species breed until the end of February and would have received benefit from the removal of the 504 rats that Clint trapped during January. The increase for grey warblers, 14 to 27 (93%) and tomtits, 7 to 8 (14%) was less and no doubt due to the fact that they finish breeding in December/ January.

At seven bird count locations outside the rat control area there was an increase of only 8% in bird numbers. This reinforces the devastating impact that rats have on the smaller bird species. Since rat trapping began in December, a total of 1340 rats have been removed from the forest.

Total Birds Seen and Heard: 16 April 2005 and 20 April 2006:

Trapping Results in Puketi Forest

We use tracking tunnels to monitor rats, stoats and mustelids. By observing the footprints of the animals passing over the inkpad in the tunnel, an index of abundance is obtained. The Trust's pest eradication goals are to keep the numbers of pests below 5% in the tracking tunnels.

Now into his third year of trapping for the trust, Scott Candy has lost none of his dedication and enthusiasm. Since trapping began almost three years ago, Scott has trapped 255 stoats, 13 weasels, 2 ferrets and 52 feral cats. For more numbers, please refer to our Trapping Results Tables

The spike in rats numbers this past January was due to the trapping of rats in the core area, which was made possible by grants from ASB Community Trust and Pub Charity. Thanks to their kind donations and trapper Scott Candy's efforts for making this happen.

Left: Wendy Sporle, Kiwi Advocate for BNZ Save the Kiwi Trust and Michelle Impey, Executive Director of BNZ Save the Kiwi Trust, examine a trap on the sponsored trap line.

Line 6 was made possible by contributions from three sources. A grant from the Northland Regional Council's Environment Fund covered the cost of traps on private land on the southern and eastern side of the circuit. The Department of Conservation funded the cutting of the 3 km trap line on the western side of the circuit and contributions from the Trust's supporters was used to buy traps to place along the forest road on the northern side and along the line cut by DoC. At 15.25 kms, this is the longest circuit and has 123 stoat traps as well as SA Cat Traps.

Since last year, we have added three stoat lines, bringing the total number to 8. This will increase our management area of 2,000 hectares by 50% and leave only two stoat lines, near Manginangina Scenic Reserve, to be added to achieve our stoat control goal. Two of these additional lines were funded by the Bank of New Zealand Save the Kiwi Trust.