From backyards to bushland, NT frogs croak secrets that scientists want to hear
That croaking frog keeping you up at night could be sharing an important message that scientists want to hear.
You might not be attracted to the loud croak, but it's actually a kind of love song between the amphibians.
"Only male frogs make that noise and it's an attempt to lure females to them, so it is them singing love songs at night," self-confessed frog person Jodi Rowley said.
Dr Rowley, who is also the curator of amphibian and reptile conservation biology at the Australian Museum, is in Darwin trying out a new citizen science app.
Researchers are hoping it will help map frog populations across Australia and take the guesswork out of amphibian identification.
FrogID identifies various frogs based on their calls, which users can record and submit.
"By listening in and recording with our phone, we can tell who's out there, who's breeding and what species we have around us," Dr Rowley said.
Dr Rowley is encouraging citizen scientists to record croaking frogs anywhere, from their backyards to bushland, which happened to be where the ABC met her to explore more about Darwin's frog population.
Putting it all on the line for love
All was relatively quiet until night fell.
Then, the swampy area came alive with a chorus of calls.
"The males are advertising to females, so they're trying to be as loud as possible, which makes it easier for us to narrow in and record their call," Dr Rowley said.
But that same volume also draws the attention from the predators in the richly biodiverse area.
In other words, the frogs are putting it all on the line for love.
While some species have year-round breeding seasons, many of them rely on the nearby puddles to lay the eggs that will hatch into tadpoles.
This is why they come out in song after heavy rainfall.
It also means that the humid, puddle-filled climate of the Top End's wet season is a boon for local frogs.
Croaks, barks and chirps vital for science
Frogs don't just croak — they chirp, whistle and bark too.
"They have quite a specific call to attract their own species because they don't want to get it wrong," Dr Rowley said.
"It would be a waste of everyone's time and effort if they got it wrong.
"Some also have a little angry territorial call if they want other males to stay away from their special spot in the pond or the creek."
She said capturing these calls could help fill gaps in knowledge about Australian frogs, especially in the Northern Territory's more remote areas.
"There are vast areas of Australia that haven't been surveyed for frogs — maybe they've got a couple of surveys of things — but it's just a real, big lack of information," she said.
"Particularly in the Northern Territory, it's a very real possibility that someone will discover a new species of frog just using their phone."
Experience tells Michael Hammer, who curates fish collections at the Museum and Art Gallery of the NT, that there is plenty of scope for new, local discoveries.
"We do have a really rich fauna but — it's about the unknown unknowns — there's so much stuff we don't know about," he said.
"Every week, I get a new record or a new species turning up, so there's still so much to learn."