Why on earth do you study roads?

When I tell friends and family that I work in road ecology I might get a polite smile and nod, or hear, ‘I thought you worked at the zoo?’ (sometimes it’s easier to say you’re a zoologist than explain what an ecologist is). When I tell other researchers I feel just a little bit pigeon-holed, because it sounds like I literally only study a narrow strip of the landscape. So, this post is to open up the field of road ecology to people who might not be familiar with it. Mum, please pay attention.

Road ecology has only really evolved as a discipline over the last few decades. In hindsight, it was a glaringly obvious environmental issue that nobody had thought to address. In 2003 it got it’s very first text-book, Road Ecology: Science and Solutions, and there are now two international conferences devoted entirely to road research. Road ecology deals with all of the environmental impacts of roads, but I’m primarily interested in the effects on wildlife.

So what are the impacts of roads on wildlife?

Roadkill is the very public face of road ecology. The sight of a galah standing steadfastly behind a fallen partner on the side of the road is nothing short of heartbreaking. Many of us have been unlucky enough to hit something ourselves, leaving a sickening feeling in the pit of our stomach (and often, a disturbing reminder on the windscreen). But the impacts of roads on wildlife go far beyond this. Building roads means habitat is cleared and this can be a major blow in areas where remnant habitat is already scarce. Then, traffic noise and disturbance can make the habitat surrounding the road a generally unpleasant place to live. Finally, have you ever had trouble crossing a busy street? Take the time out to think about how a turtle or hedgehog manages it. You guessed it – not very well. Roads can be a big barrier to movement, preventing wildlife from moving through the landscape and doing everything that they may need, or want, to do. Many animals won’t even try and cross wide or busy roads and those that do risk ending up flattened, taking us right back to the roadkill problem.

Oh no! How can we stop the carnage?

All of these impacts can lead to population declines and local extinction, particularly for species which are already under threat. But fear not, for the very same discipline that studies the impacts of roads, also investigates clever ways to reduce them. The two main methods are building fences to keep animals off the road and crossing structures to help them move over or under it. Millions of dollars are spent worldwide on crossing structures and there’s a design to suit almost everything from fish to elephants. The idea is that these structures allow animals to move safely across the road and go about their business. Do they work? Well, for most species we know that animals will use them. What we don’t know, is whether or not putting in crossing structures prevents populations from going extinct. To figure that out we need to look at things like population size, breeding patterns, survival (or roadkill) and gene flow, and see whether they improve after crossing structures are installed.