The massive loss in the number of large trees with hollows is occurring in urban, agricultural and forestry landscapes globally.
It is particularly problematic in urban areas due to clearing for development and tree or branch removal to reduce risk to people and property.
Historically, nest boxes have been used as replacement hollows, but numerous issues in the efficacy of nest boxes have recently been raised, despite using nest boxes in Australia for more than 40 years.

In response, there has been a dramatic push in the last few years to install carved hollows in standing trees, with hundreds or possibly even thousands now being installed annually.
A pertinent question is ‘Why did it take 40 years to realise nest boxes are sub-optimal, and will it take another 40 years before we are confident of the efficacy of carved hollows’?

In this presentation Rod will explain why all land managers and arborists who install carved hollows must accept that every installation is an opportunity to ‘learn while doing’.  Furthermore, it is only by collaborating and taking an experimental approach that we will rapidly be able to answer the numerous questions surrounding the efficacy of carved hollows with maximum certainty.  Rod will then highlight the key components of scientifically robust experiments to guide land managers and arborists in their hollow-creation work.

Steve will explore initial findings from several Victorian-based research projects investigating the effectiveness of chainsaw-carved hollows.

Dr Rodney van der Ree

Dr Rodney van der Ree is the Australian National Technical Executive – Ecology, with WSP, a multi-national specialist engineering consultancy.
He is internationally recognised for his expertise in urban ecology and road ecology.
Rodney is also an Associate Professor at The University of Melbourne and continues to undertake research and supervise students in Australia and internationally, including Africa, Asia, Europe and the Americas.
He has published extensively, with over 70 refereed scientific publications, 120 conference and community presentations, 100 reports and popular articles and dozens of media presentations.
Rodney published the international award-winning “Handbook of Road Ecology” (Wiley, 2015), with 63 chapters by more than 100 authors from 25 countries.
He has advised the European Union on habitat fragmentation issues and sits on expert advisory committees for the Swedish Transport Administration and VicRoads. He has supported the development and growth of road ecology research and mitigation programs in South Africa, Singapore, India, Taiwan, China, Japan and South America.


Dr Steve Griffiths

Steve is a Research Fellow in the Department of Ecology, Environment & Evolution at La Trobe University, Melbourne. His current research is focused on quantifying the effectiveness of different types of artificial hollows in providing supplementary nest and den sites for hollow-dependent fauna in human-disturbed landscapes.

Along with collaborators from The University of Melbourne and The Arthur Rylah Institute for Environmental Research, Steve is involved in several projects looking at the pros and cons of using traditional timber and plywood nest boxes, versus novel, largely untested types of artificial hollows, such as log hollows that are salvaged from felled tree limbs, and cavities carved with chainsaws directly into the trunks and branches of live trees.

Steve’s other research interests include the ecology and sociobiology of tree-roosting insectivorous bats, and mitigating risks associated with wildlife interacting with polluted anthropogenic water bodies.