Remote recordings help hihi survive
A Taranaki native bird sanctuary has made a conservation breakthrough in recording the calls of one of New Zealand’s rarest birds without disturbing their natural behaviour.
Rotokare Scenic Reserve Trust (RSRT), with the help of scientists from the Zoological Society London (ZSL), used remote recorders to listen in on the bird call of the hihi, or stitchbird.
The recording method is being touted as a breakthrough for conservation.
Rotokare Scenic Reserve Trust sanctuary manager Simon Collins said hihi, meaning ‘first ray of sunshine’, was associated with health in Maori culture.
‘‘Essentially, they’re an age-old indicator of a healthy forest. Not only are they important to protect but have proved to be a unique and ideal model to study the effectiveness of this new technique, which has huge potential for reintroduction programmes for other species,’’ he said.
Conservationists and scientists used acoustic monitoring devices to listen to the hihi and study the birds movements without disturbing its natural behaviour pattern.
Scientists saw the calls change from an initial random distribution to a more settled home range – marking the hihi reintroduction and the new method a success. For example a ‘happy’ hihi call sounded like two marbles clanging together to create the recognisable ‘stitch’ sound, Collins said.
ZSL and RSRT have both worked to increase the hihi population from one to seven new populations across northern New Zealand.
Forty juvenile hihi were released into Rotokare reserve in April 2017 – the first time the species had been returned to Taranaki since disappearing from the region around 1889.
The hihi was once found across northern New Zealand and is now classed as ‘locally extinct’ in the area due to habitat loss and predators.
Currently there are only a few thousand adult birds left in highly protected reserves, such as Rotokare.
ZSL Institute of Zoology senior research fellow Dr John Ewen said hihi were an important native species and played a crucial role in pollinating indigenous plant species, and needed a pristine environment in which to thrive.
‘‘Reintroduction, or translocation, was the most effective conservation action for saving the bird in New Zealand but, as with other reintroduction programmes for other species around the world, we’ve found it can be challenging to accurately monitor their success,’’ Ewen said.
‘‘Physically monitoring animals in the field or fitting them with radio-trackers can be invasive, expensive and more importantly can influence the behaviour or survival of released individuals, which could drastically influence our understanding and outcome of the reintroduction.
‘‘Using acoustic recording devices enabled us to remotely monitor the birds we released, giving us a true understanding of how they settled postreintroduction.
‘‘This has really exciting implications for the reintroduction programmes of many other difficult to monitor endangered species globally.’’
Manchester Metropolitan University, PhD student Oliver Metcalf said recording and listening to the hihi calls allowed scientists to understand how the birds were using the area they had been reintroduced to.
‘‘Using the calls, we found the birds moved from an initial exploration phase around the habitat, to a settlement phase, meaning the birds had established their own territories, or in other words, a sure sign of a happy hihi.’’
The results of the study have been published in ‘Methods in Ecology and Evolution’.