Goldilocks Nest Boxes Boost Survival Prospects for Endangered Greater Gliders

The greater glider (*Petauroides volans*), Australia’s largest nocturnal gliding marsupial, inhabits old-growth forests of eastern Australia. Tree hollows required for nesting can take more than a century to form, and the 2019-2020 bushfires destroyed roughly one-third of the species’ remaining habitat. Combined with climate change, deforestation and an 80 % population decline over the past 20 years, the glider has been listed as endangered since July 2022. Conventional wildlife boxes, with thin walls and poor thermal protection, have proven unsuitable because they can cause overheating, a life-threatening condition for gliders.

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In response, a partnership among Australian National University (ANU), Greening Australia and the World Wide Fund for Nature-Australia (WWF-Australia) engineered insulated, fire-resistant nesting boxes coated with a non-toxic, heat-reflective material. Dr Kita Ashman, Threatened Species and Climate Adaptation Ecologist at WWF-Australia, coined the term “Goldilocks box” to describe the design’s aim of keeping gliders “not too hot and not too cold.” Production and installation are costly, a point noted by ANU research staff. Beginning in 2023, researchers installed more than 200 boxes across Victoria’s East Gippsland and Tallaganda National Park in New South Wales.

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A 2025 study published in *Ecological Management & Restoration* reported that the boxes achieved 100 % colonisation within one year, with gliders occupying new boxes after an average of 34 days. Dr Kara Youngentob, ANU research fellow, observed that the rapid uptake “shows the individuals themselves like them and use them.” The study confirms that the high-tech boxes function as effective surrogate hollows, offering a potential tool for bolstering the species’ resilience in a warming climate.

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• Boxes installed: >200 (East Gippsland, Victoria; Tallaganda National Park, NSW)

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• Colonisation rate: 100 % within 12 months

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• Mean time to occupancy: 34 days post-installation

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• Population trend: 80 % decline over 20 years; endangered status July 2022

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WWF-Australia emphasises that the project will clarify whether expensive interventions like artificial nest boxes represent the most effective allocation of conservation funding. ANU highlights the boxes’ insulated construction and fire-resistant coating as critical innovations for protecting gliders from heat stress. Greening Australia notes that the program’s expansion, featured in WWF’s winter 2025 magazine, demonstrates ongoing commitment to habitat restoration.

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• “I just burst into tears, I was so surprised and so happy,” — Dr Kita Ashman, Threatened Species and Climate Adaptation Ecologist, WWF-Australia

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• “What we didn’t know was whether these boxes worked and whether they have an impact on the glider population,” — Dr Kara Youngentob, ANU research fellow

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• “Much to our delight, within a few months of them going up they are already being used by gliders, so we know the individuals themselves like them and use them.” — Dr Kara Youngentob

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• “They’re a treasure for this country.” — Dr Kara Youngentob

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• “I’ve affectionately been calling this design the Goldilocks box because we hope it will keep greater gliders not too hot and not too cold and will help to increase the species’ resilience in a changing climate,” — Dr Kita Ashman

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While short-term occupancy is confirmed, long-term effects on population recovery remain unmeasured. Ongoing monitoring will assess whether widespread box deployment can reverse the species’ decline, and cost-benefit analyses will determine scalability across other threatened arboreal marsupials.

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