Hollows for Habitat Project Creating critical habitat diversity for hollow dependent species.

Since 2018, the Mt Leura & Mt Sugarloaf Management Committee has commenced the ‘Creating Hollows for Habitat Project’, which aims to accelerate habitats for hollow-dependent fauna. The Project is ongoing and only one of many activities being undertaken to help restore the landscape and biodiversity that once existed on the Reserves before 1840, when European settlement began.

Australia has amongst the most hollow dependent species in the world. At least 345 Australian native vertebrate species including birds, reptiles, possums and bats rely on natural tree hollows for nesting, breeding and shelter.  Therefore, a range of hollow types is essential for developing a healthier biodiversity on our Reserves.

In eucalypt trees, small hollows may take over 70 years to develop and large hollows 200 years and longer. The first trees planted on the then treeless Reserves, began in 1995!

None of our native vertebrates for example, parrots, cockatoos, bats can create their own hollows, but they can modify existing hollows to suit their needs. Hollows in fallen trees are equally important for species such as the echidna, lizards or other reptiles. Invertebrates, such as insects, also use hollows and in fact play an important role in their formation.

Although ‘Nest boxes’ provide adequate artificial short-term habitats, they typically only last around ten years compared to a tree hollow that may exist for over 100 years.

With the existing gum trees finally becoming large enough, the Management Committee through grants and Council funding, are now focusing on the creation of artificial cavities. Creating ‘ready to use’ hollows in dead trees and ‘targeted wounding’ to accelerate hollow formation in living trees are crafted by a qualified arborist. These are superior compared to man-made nest boxes. They exhibit very similar temperature, ventilation and humidity (microclimates) to the inside of naturally occurring hollows.

Habitat hollows are manipulated to specific dimensions required by our more common species.

Habitat trees can be chosen for a number of reasons. Such as, native trees not indigenous to our area or a tree that needs to be pruned. Hollow trees are chosen for their size and location on the Reserves. Having dense canopy tress nearby hollow trees provide shelter for small mammals and birds from predators, where as, larger mammals and birds are comfortable in hollows that are in more open areas.

From 2018 to the end of 2022, approximately 40 habitat hollows of various sizes have been created utilizing 16 trees.