Much of Australia’s fauna relies on tree hollows for roosting, shelter or nesting, including a fifth of our bird species, a third of our reptiles, and nearly half of all mammals.
But big trees have declined dramatically, as they have been removed for construction timbers, firewood or cleared to allow farming. Old growth trees will often contain dozens of hollows, and those left standing are few and far between. Younger trees from revegetation or regrowth aren’t old enough to contain hollows; it takes 100 years and longer for the slow work of termites and fungi to work their magic and create sufficiently large cavities in trunks and branches.
In the meantime, installing nest boxes is a good way to support hollow-dependent wildlife in reconstructed habitat.
Our nest boxes are constructed from non-treated, long-lasting timbers in a range of shapes and sizes, and with varying entrance hole diameters. Each species has particular requirements, so to provide homes for the greatest diversity of hollow-loving animals, we need to provide a diversity of boxes too.
Based at Frahns Farm, Monarto and the Monarto Woodlands Conservation Park, this project is investigating how the different designs of nest boxes (size, entrance size) and their spatial distribution influence what creatures occupy them. We have installed our nest boxes at a range of different heights and aspects and we regularly monitor these in spring to determine the use the different boxes by different animals. We also maintain and repair the nest boxes and ensure they are not taken over by feral honeybees or invasive species, like Common Starlings.
This research will inform Bio·R’s planning and installation of nest boxes in the future. With a better understanding of how species use nest boxes, we can more effectively tailor them for our hollow-dependent mammals, birds, reptiles and invertebrates and thus create better habitat for our wildlife.
Number of nest boxes installed: 525
Number of species recorded using nest boxes: 15
Key species using these nest boxes: Western Pygmy Possum, Brush-tailed Possum, Lesser Long-eared Bat, Australian Owlet-nightjar, Southern Whiteface, Brown Treecreeper, Chestnut-rumped Thornbill