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Tree Hollows and Bush Rock - Homes for Wildlife

Tree Hollows and Bush Rock - Homes for Wildlife

How do Tree Hollows Form?


Tree hollows form in the trunk or branches of live or dead trees, and usually are found in much older trees, typically 100-150 years old. 

They vary in shape and size, and form as a result of limbs being broken off in the wind, lightning strike, fire or after attack by termites, other insects or fungi.

Because they take so long to form, and are such important habitat for many of our native animal species, it is vital that they are retained wherever possible.

Why are Habitat Trees Important?

Hollows are an incredibly valuable resource for many native species. They  are used a refuge during weather events as well as protection from predators. they are also an essential roosting and breeding site for several species, including birds, bats, possums, reptiles and frogs. 

Examples of animals that use hollows in our shire include Glossy Black Cockatoos, Powerful Owls, Sugar Gliders, Squirrel Gliders, Kookaburras and the Eastern False Pipistrelle (microbat).


How Can we Help Keep Tree Hollows?

When undertaking developments or landscaping, efforts should be made  protect all trees with hollows including dead standing trees (stags) wherever possible. An arborist can assist to ensure these are kept in a safe condition. Additionally, young trees are needed to develop into trees that will form future hollows for animals.

Nest boxes

In areas where natural tree hollows are scarce, nest boxes may be used as artificial hollows for many hollow-dependent fauna species. 

It is important to recognise that whilst nest boxes may increase habitat for many fauna species, they should not be considered a replacement for natural tree hollows. 

There are also several planning, installation and monitoring considerations that come with determining whether a nest box is a suitable option for assisting native wildlife. 

To assist you or your group with deciding whether a nest box is suitable, please review this PdfNest Box Guide: Should you install a nest box?

Complementing the guide are two recording form templates:

Pdf fileTemplate - nest box recording form: installation

Pdf fileTemplate - nest box recording form: monitoring


Bush Rock

Bush rock is loose, fragile rock found on rocky or soil surfaces. Like hollows, it can take a long period of time to form and is critical habitat for many species. When available, many animals use the habitat created by bush rock as shelter to avoid extreme weather and bushfires, protection from predators and nest sites for reptiles. Plants such as mosses, lichens and liverworts also thrive in areas with bush rock.

In order to retain this valuable habitat, it is important to minimise disturbance to rocks while you are out bush walking or mountain biking. Bush rock should also not be taken from the bush for landscaping purposes. Click on the link to a short video below for more information.

Last Updated: April 21st, 2020
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