We have established a 'core area' of about 600 hectares within the Maungataniwha Native Forest where predator populations are being reduced in an effort to provide a safe place for a variety of native bird species to breed.
Target predators are primarily possums and rats, and the birds we’re aiming to protect include the threatened species of Kaka, Yellow-Crowned Kakariki, Long-Tailed and Shining Cuckoos, and Kereru.
Work started on establishing the core area, centred on the Waiau camp, during 2009. In order to make baiting easier and more effective, old logging tracks were cleared to allow quad-bike access and walking tracks were cut every 150 metres. Bait stations are spaced at 75 metre intervals along these tracks.
The Hawke’s Bay regional Council provided 500 bait stations, Daryl Oliver of Galatea donated 30, and 150 were purchased by the Trust. Pindone and Ferratox (encapsulated cyanide) are placed in each station.
Our target through the core area was to reduce rats to less than five percent rat tracking and possums to an RTC (Residual Trap Catch) of less than two percent.
The operation was only partially successful after the first season. Rat numbers were reduced only to 10 percent but possum numbers were lowered to the targeted level. Approximately 500 possums were killed within the core area.
We believe pig interference with the bait stations reduced the effectiveness of the rat-poisoning operation. Greater emphasis is now being placed on reducing pig numbers.
Five minute bird counts were conducted at 100 sites within the core area between 12-15 March 2010, between 7am and 12 noon. Counting stations were positioned on roads and tracks and spaced at no less than 225 metres. This exercise provided baseline data against which future counts can be measured.
Species which were observed or known to be present include Kaka, Morepork, Kiwi, Whio, Kotare, Pheasant, Quail, and Long Tailed and Shining Cuckoo. At Pohokura we’ve been busy removing Pinus contorta, a variety of pine tree which spreads vigorously and grows quickly to suppress native vegetation. So far we’ve removed at least 2,729 seedlings and shrubs and 264 mature Pinus contorta from Pohokura and DOC land.
We’ve also been eliminating possums to help protect our population of Pittosporum turneri, a shrub or small tree ranked as ‘Nationally Vulnerable’ by DOC. This is the most threatened ranking of any species yet identified at Pohokura and our estimate of the total number of plants here exceeds 1,000 - five to 10 percent of the estimated population remaining nationally.
Possums pose a major threat to Pittosporum turneri, browsing and killing the juvenile plant and suppressing the emergence of adult foliage. Since on-going periodic aerial 1080 poisoning for possums began in 2005 we’ve seen the emergence of adult foliage and seed. In 2008 and 2009 seed pods were collected and taken to Taupo Native Plant Nursery for propagation, with the intention of returning any resulting plants to Pohokura. Continued possum control and the propagation of seed to establish another population to the south should further safeguard the plant here.
© Forest Lifeforce Restoration Trust.