Frogs in farm dams
Michelle Littlefair, PhD student, Fenner School of Environment and Society. This article originated from the Sustainable Farms e-newsletter.
This spring saw the completion of my first season of fieldwork as part of my PhD project. Through my research I hope to learn more about the distribution and breeding patterns of frog populations in agricultural landscapes and how to best manage and restore farm dams in order to support, and hopefully improve, the declining frog populations of Australia.
During spring I visited 60 fenced and unfenced dams across 18 farms throughout the South West Slopes of NSW. I initially surveyed each dam for habitat quality during the day then followed up with two night time frog surveys.
Each frog survey was divided into a ten-minute call survey where I listened and recorded each species and individual frogs calling, and an active search survey where I looked for frogs, tadpoles and eggs through vegetation, around leaf litter and logs and along the water’s edge. I also set up audio recording devices at 36 of the dams which recorded continuously throughout the night over ten days.
While my research is far from finished, I did make a few interesting observations. In general, fenced dams had considerably more species and more individuals than unfenced dams. Dams accessed by cattle and with little or no vegetation almost always had no frogs present. Most fenced dams had three to four different species of frog, generally the eastern sign-bearing froglet, Peron's tree frog (pictured), spotted marsh frog and giant banjo frog. However a few especially busy dams had six species, with the addition of the smooth toadlet and common eastern froglet. Having this many frog species is a great indication of a healthy dam with a well-functioning ecosystem.
