Is there anybody out there…?
Down in deepest South Westland lives a kiwi called the Haast tokoeka. It was named for its oversized beak, and translated from Te Reo tokoeka means bird (weka) with a walking stick (toko).
Tokoeka are under attack from introduced predators, particularly stoats, so their home between the Arawata and Waiatoto rivers is protected, as the Haast Tokoeka Sanctuary. The Sanctuary has been blitzed with intensive stoat trapping since 2001.
Dedicated Haast tokoeka kiwi rangers follow the lives and loves of about one hundred pairs of adult tokoeka wearing radio-transmitters on their legs. That way they can protect the young birds through BNZ funded Operation Nest Egg.
The Sanctuary protects a stronghold of tokoeka in South Westland, but they are not alone in the world. Anecdotal accounts from hunters and locals led DOC to investigate further up the Arawata River and another population was found. Now the kiwi team wants to find and monitor more of these Sanctuary neighbours, so they can increase the gene pool for tokoeka conservation and extend their distribution in case of environmental disasters.
After all it’s better not to keep all your tokoeka eggs in one basket!
Instruments of detection
The extraordinary sensory perception of dogs’ shnozzes has been used for years to sniff out kiwi. Here in Haast our own Blair Hoult and kiwi-dog Tussock have found six new tokoeka together.
Both these methods are very labour intensive and it is helpful to know if there are tokoeka about before sending in the rangers. DOC’s Research and Development Team have developed a new device for recording bird calls, which has the potential to find new tokoeka with minimal time in the field.
Trainee Ranger Chris Bowen recently set off to test this new technology in the wilds of South Westland.
To test the reliability of recorders in the field Chris and Blair pulled on their beanies at dusk for a cold night listening beside a recorder set high up in the alpine tussock of the Sanctuary. Analysing the acoustic recording back in the office Chris found that it had picked up 78% of the calls he and Blair heard sitting on the mountain.
Next Chris used the recorders to search for new tokoeka outside the sanctuary. When he got them back in the office he was excited to find that one of the recorders had picked up a new pair serenading each other. Three days later Blair and contractor Chris Rickard headed into the same area with Chris’ kiwi dog. They caught and put a transmitter on a new adult female, which has been named Downpour Torrent after a nearby creek (it rains a lot here!).
Demonstrating that these recorders work well in the field is great news for managers trying to make savings. Whereas, staff time for one hundred hours of call listening costs DOC around $2000, an acoustic recorder will listen for one hundred hours for the price of four AA batteries.
The acoustic recorders are continuing to be trialled on various bird monitoring projects around New Zealand and will really improve efficiency. Technological advances in species monitoring free up valuable time and resources for DOC to protect more vulnerable species.