A new frog species on Edgbaston Reserve
Picture this: It’s a balmy spring evening and you’re volunteering on Edgbaston Reserve, Bidjara Country, semi-arid western Queensland. Sprawling constellations are lighting up the night, and it’s time to put on your gum boots for a routine cane toad survey. Dean Gilligan, Freshwater Ecologist for Bush Heritage, is leading you along winding trails towards the Great Artesian Springs where threatened Red-finned Blue-eyes dart below the surface – a tiny fish at the heart of Edgbaston’s conservation value.
“You’ll be able to hear frogs and toads calling and find them with your torch,” says Dean.
Almost immediately, amidst a chorus of frog noise, you spot big common Green Tree Frogs jumping between the reeds. Game on!
Recently, Edgbaston has been wetter than usual. The springs usually provide an oasis in an otherwise dry and semi-arid landscape, but after rain, the reserve is alive with colour – water from above and below.
“After rain,” Dean says, “particularly heavy rain, the calls of frogs can be deafening - it's a very froggy location.”
After snapping a few photos of Green Tree Frogs (Litoria caerulea) and Broad-palmed Frogs, (Litoria latopalmata) something unusual catches your eye – a stripy fellow lurking in the mud with long legs and an elongated body. Later, you’ll learn that this marks a special occasion for not only Dean but for the whole ecosystem. It’s a Striped Rocket Frog (Litoria nasuta) and its discovery indicates a significant western range expansion. Dean is brimming with excitement.
“It’s really an east coast thing,” says Dean, “it shouldn’t be in the arid zone!”
It’s the second unusual frog discovery on the reserve recently, with a Beeping Froglet (Crinia parinsignifera) recorded a few months prior, also far from its range. Dean believes the recovery of revegetation around the springs has had a positive impact on frog numbers. It’s also a reflection of the distinctive habitat the springs provide, supporting isolated populations of unusual critters.
“The fact that the Great Artesian springs are a permanent water supply”, says Dean, “has let at least those two frog species and perhaps even a couple more live through the climate changes that have happened elsewhere.”
“Where other parts of the country have become drier, the springs have kept remnant populations alive, despite retracting distributions,” says Dean.
It’s time to retreat to the homestead. It’s 10:30 pm at the end of a long day in the field, the team is rightfully exhausted. You go to sleep and dream of Striped Rocket Frogs leaping great distances through the crisp spring air.