Melbourne's urban forest plays an important role in supporting biodiversity in our city. As trees age, they can develop hollows and cracks that provide shelter for a range of animals, including birds and bats.

We know that tree hollows are important, but we have limited data about which trees have hollows and how they are distributed throughout the City of Melbourne. That's why we need your help!

Citizen Foresters are invited to help us build our database of trees with hollows. We'll be visiting parks and streets to look closely at the trees and record information about hollows. This data will help to inform the way that we manage trees and plan for habitat in the future.

There are almost 80,000 trees throughout the City of Melbourne, so we will be collecting tree hollow data at lots of events over the next couple of years. This means there will be plenty of opportunities for you to get involved!

Look out for more Citizen Forester Hollow Mapping events in winter 2023.

In winter and spring of 2019 the Citizen Foresters successfully mapped all of the trees in Fawkner Park. Citizen Foresters surveyed Fawkner Park looking for hollows in each tree and with their continued effort we were able to collect data for every single tree! The commitment and enthusiasm showed by our participants was wonderful.

We’ve now published the results from these events. Below you’ll see a map representation of the results, select each tree to find out whether it has a hollow or not.

2022 hollow mapping events complete

September 2022

In September 2022 over 60 Citizen Foresters came out to help us collect tree hollow data in Carlton Gardens. Based on previous years' events we have refined our data collection process making it much easier for event attendees. With their enthusiasm we were able to complete all trees within the park. Whilst identifying hollows we also spotted possums, lorikeets and some mistletoe. Check out the photos below.

Data collection event completed in Royal Park

March 2018

30 Citizen Foresters came out to help us record habitat trees in Royal Park on the 23rd of March. There were so many trees that it was a slow-moving process, but it was exciting to see so much habitat potential in some of the older gum trees. Volunteers also became quite good at using the specialist equipment, including the DBH tapes and laser rangefinders!

Trial data collection event complete!

June 2016

Thanks to everyone who came out to help us identify habitat trees in Fitzroy Gardens! It was a rainy day but we still had about 30 enthusiastic Citizen Foresters who helped us to test the method for identifying trees with high habitat value.

The results have been analysed to create a map showing the trees that were found to have high habitat value.

In addition to collecting data, the Citizen Foresters provided feedback about the data collection method. This input will be used to refine the approach before habitat Tree Identification is carried out more broadly across the City of Melbourne.