Saving species with nest boxes
Australia's remaining woodlands are rich in biodiversity and home to unique species like my favourite cockatoo, the adorable Gang gang. But habitat loss and fragmentation, invasive species, climate change and bushfires are taking their toll. Gang gangs officially took a step closer to extinction last year when they were up-listened to endangered by Australia's Threatened Species Scientific Committee. Already in trouble, 30% of their habitat was burnt during the 2019-2020 bushfires.
At Wombat Ridge Nature Reserve in the Southern Highlands of NSW, habitat supplementation through provision of artificial nest boxes is supporting Gang gangs. Placed high in the trees across 50 hectares, specially designed PVC nest boxes are providing additional breeding sites for the birds. They may not look pretty, but the boxes are durable and designed to mimic natural tree hollows that the birds favour for nesting.
I see three key benefits of nest boxes as a means of supplementing habitat. Firstly, of course, they provide additional breeding sites. Many of Australia's woodlands have been selectively logged which removes the oldest trees that have the best nest hollows. Introducing artificial hollows can thus improve reproductive success. While definitely not a 'set and forget' measure, studies of other cockatoo species have shown that artificial nest boxes can have a positive impact.
A second benefit is the opportunity for community involvement. Nest box programs can engage the public and encourage people to take more active roles in conservation. For example, community-led Landcare programs in Western Australia have installed hundreds of Cockatube nest boxes for endangered black cockatoos. In addition to the significant direct support for the birds, these programs have brought farmers together and raised awareness about conservation. The neighbours at Wombat Ridge are interested and watching the nest box program there. In the future I hope they might choose to join in and place next boxes on their properties.
Finally, nest box programs contribute to science on saving species. They can be used to study birds' breeding success, habitat use, and movement patterns. This information is critical for improving conservation efforts now and into the future as climate change impacts really kick in. While research on the use of nest boxes for Gang gang cockatoos has so far been limited, studies by CSIRO and BirdLife Australia show that they can be effective. Monitoring at Wombat Ridge will provide further evidence and contribute to the science on Gang gang cockatoos.
To conclude, habitat supplementation through provision of nest boxes can play a critical role in supporting survival of endangered species. Nest boxes provide additional breeding sites, engage the public in conservation efforts, and provide valuable scientific data to inform conservation management. But it is important to note that habitat supplementation should always be used in conjunction with other evidence-based conservation strategies, such as habitat restoration and protection. At Wombat Ridge, the Gang gang cockatoo nest box program is underpinned by cultural burning, invasive species management, and natural and assisted woodland regeneration.
Wombat Ridge is covenanted as a protected area through the NSW Biodiversity Conservation Trust which provided a grant to support deployment of the nest boxes.