It's the latest flat-pack innovation - a biodegradable shelter that can be rapidly installed to provide refuge for native animals left exposed and vulnerable after a bushfire. Newly designed 'habitat pods', developed by Dr Alex Carthey of Macquarie University, are this week being deployed as part of a world-first Australian Wildlife Conservancy research project at North Head Sanctuary.
Intense bushfires can be deadly for wildlife, both during the blaze and in the aftermath. The artificial shelters have been designed to address the high mortality of wild animals that occurs in the weeks and months after a bushfire. Indirect impacts, such as the removal of food and shelter, make this a dangerous period for animals, and the threat is compounded by intense pressure from hungry predators. An estimated three billion vertebrate animals were impacted in the 2019-2020 Black Summer fires which burnt across an area of more than 12 million hectares in eastern Australia.
The pods are now part of a PhD project by ecologist and former Australian Wildlife Conservancy intern, Angela Raña, co-supervised by Sydney University. In 2020, Raña set out to study the role of small native mammals as pollinators of North Head Sanctuary's diverse banksia scrub. However, a hazard reduction burn that jumped containment lines in October 2020 destroyed her experiments and prompted a rethink.
"I'd been studying and monitoring the plants and animals here for two years, but after the fire we mostly found charred skeletons in the ash. It was heartbreaking." said Raña of the burn.
"With the thick undergrowth almost completely removed, any surviving animals could just be picked off by birds, foxes and cats."
Raña's project will now investigate the effectiveness of the habitat pods. Two hundred of the cardboard shelters are being deployed across parts of the headland that were impacted by the fire, for an experiment that will run for up to 12 months. It is hoped they will offer small animals short-term refuge from the elements and a place to hide from predators like feral cats, which have been shown to take advantage of easier hunting conditions post-fire.
The habitat pods themselves take the shape of a sturdy, six-sided pyramid made from folded cardboard, perforated with multiple small holes where animals can scamper in and out. Unlike the wire and shadecloth structures that have been used as post-fire shelters previously, the pods are light, easy to transport and set up, and entirely biodegradable.
Dr Carthey's design was informed by her career researching predator-prey relationships and the key realisation that availability of habitat is a critical factor after a burn.
"The Black Summer fires acted as a wake-up call, and that got me thinking about what we could do to help wildlife survive," Dr Carthey said. "I had some conversations with the team behind the Living Seawalls project (finalists of the inaugural Earthshot Prize), who are also at Macquarie University, and their designer Alex Goad of Reef Design Lab … we even experimented with 3D-printing some moulds for prototypes from recycled paper pulp, but in the end the folded design held up better in testing."
North Head Sanctuary was chosen for the first ever real-world trial of the habitat pods. The headland is the site of an ambitious mammal reintroduction program run by Australian Wildlife Conservancy, working in partnership with Harbour Trust. Three small mammal species which were locally extinct on North Head have been restored since 2017: the Eastern Pygmy Possum (Cercartetus nanus), Brown Antechinus (Antechinus stuartii), and Bush Rat (Rattus fuscipes). All three species have been recorded since last year's blaze, and are likely contenders to use and benefit from the installed habitat pods.
The ecologist leading the reintroduction program, Dr Viyanna Leo, had input into the design of the habitat pods, established the research at North Head and co-supervises Raña's research project.
"I think this work has huge potential," Dr Leo said. "Large-scale bushfires are an ongoing concern for conservationists, especially as the climate heats up. The habitat pods could be an effective new tool for bushfire response that makes the difference between life and death for thousands of native animals."
Australian Wildlife Conservancy is contracted by the Sydney Harbour Federation Trust to deliver research and monitoring projects at North Head, with a particular focus on restoring small mammals. New South Wales National Parks and Wildlife Service provided funding for the bushfire recovery research project.