Remote recording devices used to eavesdrop on a reintroduced population of the hihi, one of New Zealand’s rarest birds, are being heralded as a breakthrough for conservation.
Scientists from Zoological Society of London (ZSL), Imperial College London and conservationists from the Rotokare Scenic Reserve Trust used acoustic monitoring devices to listen in on the ‘conversations’ of New Zealand’s endemic hihi (Stitchbird).
The devices allowed them to assess the success of the reintroduction without impacting the group.
Hihi Calls Track Movement
ZSL scientists for the first time used the calls of a species as a proxy for their movement.
A happy hihi call sounds like two marbles clanging together in what is known as the ‘stitch’ call.
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.
The study took place in the Rotokare Scenic Reserve in the Taranaki region of North Island, where 40 juvenile birds were released in April 2017.
The marks the first time hihi have been seen in the region since their regional extinction over 130 years ago.
The hihi (Notiomystis cincta) once found across northern New Zealand, are now classed as locally extinct across most of their former range, due to habitat loss and fragmentation and the spread of non-native invasive mammal predators.
There are only a few thousand adults left in highly protected reserves.
Reintroduction Effective Way to Save the Hihi
“Hihi are an important native species, who play a crucial role in pollinating indigenous plant species and need a pristine environment in which to thrive,” says Dr. John Ewen, Senior Research Fellow at ZSL’s Institute of Zoology.
“Reintroduction, or translocation, is considered the most effective conservation action we can take to save the hihi bird in New Zealand, but we’ve found it can be challenging to accurately monitor their success.”
Dr. Ewen says physically monitoring animals in the field or fitting them with radio-trackers can be invasive, expensive and can influence the behavior or survival of released individuals.
This can drastically influence our understanding and outcome of the reintroduction.
Recording Devices Monitor Endangered Species
“Using acoustic recording devices enabled us to remotely monitor the birds we released, giving us a true understanding of how they settled post-reintroduction,” says Dr. Ewen.
He says this has exciting implications for the reintroduction programs of many other difficult to monitor endangered species globally.
ZSL is playing a significant role in the hihi’s recovery since 2004.
Helping to expand the population from one to seven new populations across their former range in Northern New Zealand, ZSL works closely alongside Rotokare Scenic Reserve Trust to support the establishment of this most recent reintroduction effort.
Read the study published in Methods in Ecology and Evolution.