Project status
Project collaborators
Malcolm Nicoll

Dr Malcolm Nicoll

Senior Research Fellow

Recovering olive white-eye

The olive white-eye is the rarest bird in Mauritius, with less than 150 pairs remaining in the Black River Gorges National Park. They are a living piece of evolutionary history, a part of an ancient Indian Ocean white-eye lineage with birds colonising from Asia prior to the subsequent evolution of the African species. Much like the Mauritius kestrel, they have devastated by invasive rats and extensive habitat loss.  

Before our work started, little was known about their biology, range and population size. However, through scientific research we have established an understanding of their ecological requirements and population limiting factors has been established. Our knowledge is crucial to inform the reintroduction of the olive white eye to the predator-free island nature reserve, Ile aux Aigrettes. Currently, this population of around 60 individuals, is intensively monitored and managed through the provision of supplementary feed. 

Our Africa wildlife conservation 

  • 150
    Pairs left in in Mauritius
  • 10%
    In top 10% of the EDGE bird species list
  • 3
    We're working to recover three Mauritian bird species from the brink of extinction.
  • Olive white-eye bird
    Olive white-eye bird

    Olive white-eye conservation 

    The ZSL Institute of Zoology is actively involved in the olive white eye project and, along with our conservation partners, provides scientific evidence to drive the species recovery programme. The recovery programme is implemented by the Mauritian Wildlife Foundation and the National parks and Conservation Service (Government of Mauritius), with support from the Durrell Wildlife & Conservation Trust (DWCT) and Chester Zoo. 

    Our research has provided insight on how rats significantly reduce breeding success in olive white-eyes and hence contribute to the ongoing population decline. Helping us understand how to better control this invasive species to restore olive white-eye populations. We’re trialling these predator-free solutions for the first time in Mauritius. We’re also analysing the effectiveness of the provision of supplementary feed as a conservation management tool for olive white-eyes and this may be refined in the long -term through targeted habitat management.  

    This work not only benefits the Mauritius olive white-eye but also the other endemic passerine species of Mauritius and projects globally, facing similar threats of invasive species and long-term management uncertainty by combining science, conservation and communication.  

    Hihi conservation - a tiny bird solving big problems

    Restoring populations

    • A viable olive white-eye population in the long-term. 

    • Refined conservation management actions focused on: 

      • the provision of supplementary feed; 

      • habitat restoration;  

      • and the management of invasive rat species.

    • The ecology and conservation of the Critically Endangered Mauritius Olive white-eye
      Read our scientific paper
    • The development of international collaboration to drive evidence-based species conservation 

    Recovering species globally

    When nature loses, we all do. Join us on our fight for the natural world, spanning every continent from the depths of the Antarctica to the Sahara desert. 

    Partners & Sponsors

    Partners: Mauritian Wildlife Foundation, National Parks & Conservation Services (Government of Mauritius), Chester Zoo, Durrell Wildlife Conservation Trust 

    Sponsors: Chester Zoo 

    Our global conservation work

    • Asiatic lion male lying down in wild at a chickpea field

      Protecting Asiatic lions in the Gir Forest

      There are approximately 600 Asiatic lions left in the Gir Forest of Western India, their last remaining natural habitat.

    • ZSL anti-poaching patrol in Dja reserve Cameroon
      Protecting a UNESCO World Heritage Site

      Dja conservation complex

      Empowering local people to protect their home and the wildlife they live alongside.

    • Mountain chicken frog sitting on forest floor

      Mountain chicken frog conservation

      Creating routes to recovery through cutting-edge scientific research and breeding at London Zoo.

    • Female Hainan gibbon with infant
      The world’s rarest primate

      Hainan gibbon conservation

      The Hainan gibbon is the rarest primate and possibly the rarest mammal species. There's been a severe decline in numbers due to habitat loss and hunting.

    • Wild Oryx Running
      Establishing gazelle conservation

      Gazelle conservation breeding in Saudi Arabia

      Building a foundation to restore and safeguard wildlife for years to come.

    • Guam kingfisher (Sihek) sitting on branch
      The Guam kingfisher that was wiped out by snakes

      Sihek conservation

      We're creating solutions to save the sihek from the jaws of extinction - as invasive snakes outnumber people in Guam by 10 to 1.

    • Tagging black rhino
      Reducing poaching to secure the future of this iconic animal

      Black rhino

      We’re working with lots of different partners to find new ways to fight poaching for the illegal wildlife trade – for example, with technology that uses sensors and cameras to detect humans and wildlife.

    • Our global conservation