One of the bobucks Achim equipped with GPS collars.

Credit: Achim Eberhart

~ Achim Eberhart

From my predecessors' posts, most of our loyal readers will know about the exciting and sometimes overwhelming experiences we interns have in our first weeks at COSMOS.

So I thought that instead I'd tell you a little bit about the science I myself have been involved with before starting here. For the past four years I have been studying the travels of young bobucks - or mountain brushtail possums - in Victoria. These marsupials are closely related to the common brushtail possums that have become regular guests in our backyards, parks and even major cities.

A main difference between the two brushtails is that bobucks rarely venture from their native forest habitat. But when young males reach adolescence, they develop an urge to travel. At about two years of age, these males tend to disperse, which means they leave their parents and establish their own home ranges elsewhere, sometimes more than 10 km away.

In our modern landscapes it can be quite difficult to travel such distances without leaving the forest. So I set out to follow some of these animals to see what kinds of areas they found themselves in. I used collars equipped with a radio transmitter and a GPS device to track them down and record their movements. While only three of the many animals I tagged attempted to disperse, what I was able to learn from them is quite fascinating.

If the animals couldn't avoid crossing open landscapes - in my study this was mainly pasture - they used the scarce amount of trees for rest and protection. If narrow remnants of the forest were left along roads, they used these as 'dispersal corridors' and moved directly along them. Individual paddock trees acted as 'stepping stones', allowing the possums to rest before dashing to the next one.

You may think this is not all too surprising, considering these possums are forest specialists. Nevertheless, it is very important to find proof of such behaviour if we want to make a point with it. The point being that even individual trees and very small remnants of forest are crucial for the survival of native wildlife in our 'fragmented' landscapes - even though they may not provide sufficient habitat for possums to live in. If individuals are able to cross from one forest to another, the animal populations are being mixed up, which makes them much more genetically stable and avoids inbreeding.

We can safely assume that what I observed for bobucks also applies to many other species. What this research teaches us is that wildlife conservation is not always straightforward. Sometimes we have to think outside the box when we make decisions about what needs to be protected.