In Australia many native species need tree hollows, including 17 % of bird species, 42 % of mammals and 28 % of reptiles. If future Australians are going to live in large cities with more animals around them other than cockroaches, rats, mice, mosquitoes and flies then we have to make urban areas suitable for wildlife to life and thrive

During 2015-2018, WildThings NSW successfully completed two projects entitled "Natural Hollows". It had 50 hollows successfully sourced and installed in the gardens of 50 lower north shore residents (including two schools).

A key objective of this project is to continue the number of hollows being installed throughout Sydney, which is very important due to the increase in the number of trees being cut down and reduction in habitat for animals and birds occurring in the Ku-ring-gai area.

To obtain these natural hollows WildThings NSW approached a number of local tree loppers and obtained free tree hollows from trees that had been cut down.

Large natural tree hollows can take 200 years to form, every time an old native tree is cut down, a replacement tree takes way to long to begin to be of immediate use to wildlife. Currently there are 3 ways to try and remediate this problem:
• Plywood artificial hollows
• Leaving the trunk of a tree and cutting in hollows, currently done by a small number of Sydney arborists
• Installing natural hollows instead of plywood hollows

Advantages of placing natural hollows:
• Better insulation than plywood
• Longer lasting than plywood
• Does not need the original tree in situ
• Is a habitat that wildlife is used to
• Can be configured to suit various species, largely done by size of the hollow and size of entrance

People have good intentions but often never get around to installing their hollow. To get around this WildThings NSW charges $125 to get a professional arborist to securely place the hollow. For a fee of $125 you get the hollow, professional installation and follow up attention. The $125 goes to the arborist – WildThings makes no money out of this at all

The process:
Using records and information supplied by the resident the property is examined to determine what species are likely to be present which determines the type of natural hollow used.
The hollow is then professionally installed
Records are made of the installation and the resident is contacted on an annual basis to determine the success or otherwise.
If a feral species moves in appropriate steps are taken to remove the interlopers

Photographs of each installation are taken and all appropriate information recorded in a spreadsheet as a record for further use by WildThings NSW and local government wildlife experts.
Such information will include full contact details of the recipient, physical address of installation, type of tree hollow is installed in including height above the ground and diameter of its trunk, direction hollow is facing, direction entrance hole is facing, type of animals/birds which might use the hollow as a home.

Each recipient will also receive the information mentioned above related to their hollow and encouraged to participate in the “Hollows as Homes” project being co-ordinated by the Royal Botanic Garden.

Future initiatives:
Currently this work has been largely done in the lower north shore, we would like to take it throughout Sydney
A partnership with the St Ives Community Shed to make natural hollows. This requires getting dead branches and using a technique developed by the Community Shed to turn them into a hollow.