Eavesdropping on the first ray of sunshine

By recording hihi calls (which sound like two marbles clanging together) ZSL scientists can tell where reintroduced birds have settled.

40 juvenile birds were released in Rotokare Scenic Reserve in the Taranaki region of North Island, New Zealand, in April 2017. This is the first time hihi have been seen in the region for over 130 years. The hihi (Notiomystis cincta) were once found across northern New Zealand, but 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.

ZSL (Zoological Society of London), Imperial College London and the Rotokare Scenic Reserve Trust set up acoustic monitoring devices to listen in on the calls, allowing them to assess the success of the reintroduction without impacting the group.

Scientists saw the calls change from an initial random distribution to a more settled home range – marking the hihi reintroduction as a success. Oliver Metcalf, who used the technology for his masters studies at ZSL’s Institute of Zoology and Imperial College London explained: “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.”

Hihi play a crucial role in pollinating indigenous plant species. Simon Collins, Sanctuary Manager for Rotokare Scenic Reserve Trust said: “Hihi actually means ‘first ray of sunshine’ and in Maori culture the birds are associated with health – essentially, they’re an age-old indicator of a healthy forest, and 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.”

ZSL has played a major part in the hihi’s recovery since 2004 – helping to establish seven new populations across their former range in Northern New Zealand. To learn more about ZSL’s hihi reintroduction work, visit: https://www.zsl.org/conservation/regions/oceania/hihi-conservation-in-new-zealand