Most people know the importance of tree hollows and the vital role they play in providing roosting and nesting sites for around 20% of Australian wildlife. However, not many people realise how easy it is to construct an ‘artificial hollow’ or nest box with some scrap timber and basic carpentry tools and skills. At a workshop run by Brisbane City Council’s Wildlife Conservation Partnerships Program, Alan and Stacey Franks from Hollow Log Homes, highlighted that with a little practice, anyone can build their own nest box and have the pleasure of providing a home for an Australian Wood Duck or maybe even a Squirrel Glider.
Nest boxes, like natural hollows that have formed over many years, come in many shapes and sizes and are used by different species. A tree hollow or a nest box suitable for a small insectivorous bat is completely different to that used by a large Powerful Owl. Choosing the right nest box for your property can depend on what animals you have observed in the area, which animals you would like to attract to your property, and whether your property is lacking certain sized nesting hollows in surrounding trees. By contacting your local Land for Wildlife Officer, you can find out what animal species are likely to occur on your property and construct your nest box accordingly.
Some of the landholders who attended the Brisbane nest box workshop showed great initiative by pulling apart a nest box they had built at the workshop and using it as a template to construct more boxes to put around their property. One landholder constructed another two nest boxes and within two weeks had a kookaburra checking one out.
A recent nest box survey on various Land for Wildlife properties in western Brisbane returned some great results. Animals such as Common Brushtail Possums, and Short-eared Brushtail Possums, Australian Wood Ducks, Rainbow Lorikeets, Pale-headed Rosellas, insectivorous bats and Squirrel Gliders were all observed in July/August 2012. Perhaps it was due to the cold weather, but it was certainly a busy time.
One property in the middle of suburban Indooroopilly had four out of ten nest boxes occupied with Common Brushtail Possums and a family of Squirrel Gliders present, as well as signs of activity in another two boxes. The only natural hollow in this area is a single stag tree on a neighbouring property. It goes to show that if you provide habitat, animals will utilise it. This success has convinced the environmental manager of the site to construct a further ten nest boxes out of unused plywood.
There are a few important points to remember when constructing your own nest box. Ensure any screws or nails are not protruding into the box, as the sharp points may injure wildlife. Coating the nest box with a lanolin-based product will help protect it from weathering while not harming the animal that will use it. When installed, boxes should be protected from the harsh afternoon sun and if storms regularly occur from a particular direction, try to place the box on the other side of the tree. Use sturdy wire to hang the box from a tree fork. A garden hose or another protective coating around the wire will help prevent it damaging the tree.
Most animals only need nest boxes to be three to four metres from the ground. However, larger parrots and owls prefer nest boxes to be a lot higher up a tree. Personal safety is paramount when installing a nest box so always recruit someone to be on hand to hold the ladder and assist with installation.
Once installed, nest boxes should be monitored for intrusion of unwanted guests. Common Mynas, Common Starlings and European Honeybees are the major feral species that may take up residence in nest boxes and drive away desirable native species. Non-native birds can easily be deterred by removing nesting material and closing the nest box for a while, or by relocating the nest box to another area. European Honeybees should be removed by a professional beekeeper.
There are many plans for making nest boxes available on the internet. A great reference book for nest box construction, as well as tips and information about nest boxes, is Nest Boxes for Wildlife by Alan and Stacey Franks.
Happy nest box building.
Article by Cody Hochen
Land for Wildlife Officer
Brisbane City Council