Pukaha Mount Bruce National Wildlife Centre has completed a comprehensive survey of the kokako living in the reserve and the results have been impressive.
The intensive kokako census completed in October 2016 has identified 30 pairs of kokako currently living in the reserve with a conservative estimate of 9 other juvenile birds sighted during the survey.
North Island Kokako from the Pureroa Forest Park were first released in to the Pukaha forest in 2003 with a further two birds from Kaharoa Forest in 2010. Kokako from a breeding programme run at Pukaha were also released in 2004 and 2006.
Since the releases into the reserve there have been a number of walkthrough surveys undertaken, the last of which in May 2014 identified 29 individual birds.
The most recent census was done over four weeks during September and October and took 49 person days to complete. It was made possible by funding from Pub Charity Limited and Pukaha Mount Bruce was able to purchase equipment and contract specialised personnel, Dave Bryden and Joel Henton, who work extensively with kokako.
“This was a really comprehensive count and the final tally surprised even our experienced contractors. This confirms for us that our rat control operations are working in the Pukaha forest” says conservation manager Todd Jenkinson. “Thanks to all the years of hard work by Greater Wellington Regional Council & Horizons Regional Council in our buffer zone and the Department of Conservation and the Pukaha volunteers in the reserve, we are at a point where our kokako are breeding well and surviving through the tricky breeding seasons when rats can really knock them back. Thirty pairs is an outstanding result and we intend to keep working hard to increase these numbers into the future”.
North Island Kokako census information:
Kokako are territorial and their range is up to 8 hectares. They sing and chase away other birds from their territories.
There are approximately 1,400 pairs in New Zealand at 2014 (Source: Department of Conservation website – www.doc.govt.nz )
Only paired territorial birds are counted in a formal census.
The formal census involves walking transects at approximately 200 metres apart from dawn until mid afternoon while listening for kokako. When kokako were not detected, pre-recorded local dialect (song) was played at 200 meter intervals along the transects to elicit a response from territorial birds.
All birds which were seen or heard were followed for 30 minutes. If they met the required criteria to be determined as a territorial pair, the GPS location of the pair was taken and they were confirmed as a pair.
The criteria for determining a pair is:
- One ‘follow’ of at least 30 minutes in which one bird of the pair must sing their full song
- Or two 10 minute ‘follows’ over two different days in the same location