Bringing back a lost species
The distinctive blue wattles and beautiful, multi-toned calls of the North Island kōkako (Callaeas wilsoni) were once commonplace on Mt Pirongia and we are working alongside the community to make that a reality again.
The last kokako captured on Mt Pirongia in the 1990s to stop that lineage dying out (Photo credit: Gerry Kessels)
Interesting facts about kōkako:
They defend their territories using complex singing and they hold the record for the longest known duet of any songbird in the world
They pair for life and breeding pairs will defend a territory of 4 to 25 hectares
They are poor fliers. Kōkako use their strong legs to bound around in the trees but can glide for hundreds of metres!
They favour tall native forest dominated by tawa (Beilschmiedia tawa). Mt Pirongia has extensive groves of large tawa.
Kōkako populations can only persist in native forests with areas that are actively managed to reduce mammalian pests. Rats, possums and mustelids (stoats, weasels and ferrets) can decimate bird populations by eating eggs, overgrazing food supplies and killing chicks. Our community based pest control dating back to 2006 has allowed us to create a habitat in which kōkako can thrive once again.
Our amazing volunteers make it possible for us to protect kōkako in two native forests: Mt Pirongia and Northern Pureora.
We are proud to have re-established a lost species on Mt Pirongia by bringing kōkako back to the maunga in 2017. Through translocation, monitoring and pest control efforts on 1,030 hectares of the forest we are now seeing the successful breeding and fledging of kōkako chicks.
Our post release monitoring is used to inform effective predator management to help newly established populations to grow rapidly. From our surveys we know that 82% of our 44 translocated birds have been re-sighted since release and that as at 2020 we had 11 unrelated founders (nesting pairs producing chicks on Mt Pirongia).
Mt Pirongia Monitoring Results
Below is a selection of photographs of Pirongia kōkako.
Okahukura, Northern Pureora
Northern Pureora Forest has five key kōkako clusters: Mangatutu and Tunawaea Valley in the north, Okahukura in the centre and two in Waipapa to the south. As the largest and most genetically resilient sub-population in New Zealand, Northern Pureora is the strongest source for birds to translocate to other areas. Our group set up a 1,000 hectare bait station grid at Okahukura Valley in 2015. This intensive pest control helps to increase connectivity between sub populations resulting in improved genetic health of the species as a whole and increasing the number of birds that can be translocated and re-established in other areas.
Annual monitoring cost of one kōkako - $2,500
Support for contractor services eg accommodation /equipment - $1,000
Pest Control Protection of 1 pair (10 ha) - $300
Health Screening for 1 kōkako - $125
Pest control protection for 2 hectares - $60