Daniel F. Martinez-Escobar U5182783
Box-Gum Woodland once covered a large area of south-eastern Australia. It is home to various species of birds, lizards, frogs and invertebrates. However, since European settlement began, 92% of its area has been cleared for grazing and agriculture. The remnants of these woodlands are often small and scattered. This habitat fragmentation is challenging for small animals to move across woodland patches, increasing their risk of extinction. What if we could find cost-effective ways to connect these fragments to prevent further loss?
I did my work experience with PhD candidate Stephanie Pulsford, whose research aim is to try solve the connectivity issue in remaining Box-Gum Woodland patches. Her research is focused on reptiles and frogs, which are vulnerable to extinction by habitat fragmentation. Travelling from one patch of woodland to another can be easy for larger animals such as birds, but difficult for lizards and frogs as they are more sedentary and vulnerable to predation and desiccation. This is more difficult when the space between patches (known as the matrix) has been oversimplified by human impacts such as grazing and the removal of fallen timber. Stephanie’s research is trying to find ways to create stepping-stones allowing these animals to move from one patch of woodland to another. Some of the stepping-stones being tested include fallen timber, fences, and plant corridors.
When we arrived to our first site we encountered a landscape similar to the usual surroundings of Canberra: golden dry grasslands, herds of sheep, fences, scattered patches of forest and the occasional mob of kangaroos. Our task for the day was to install traps throughout different sites. When a lizard or a frog decides to move from one patch of woodland to another, they would encounter a large drift fence. When trying to run around the fence, they would fall into one of the pitfall or funnel traps placed throughout the drift fence. These traps are designed to capture and keep them alive until we find and release them.
During the following days, we would travel to each of the sites to check if any lizards or frogs had fallen into a trap. We would note from what direction they were traveling from, and their physical characteristics. The specimens were then tattooed with a combination of fluorescent dyes for identification. Unfortunately, the days were cold, so not many animals decided to move across patches. Nonetheless, each new specimen trapped was an exciting find. We even found a tiger snake!
It is too soon to know which stepping stone strategy will mitigate fragmentation effects in Box-Gum Woodlands. Nonetheless, this research is promising. Interested farmers will be able install these stepping-stones at little financial expense to help increase the populations of lizards and frogs, which bring benefits to the ecology of their properties.
The development of these stepping-stones can be applied as a broad-scale restoration method to improve the chance of survival of reptile and frog species living in Box-Gum Woodland remnants and may even assist other endangered habitats around the world.
All text and photos by Daniel F. Martinez 2015