The call of the Tanami toadlet has been recorded by researchers for the first time since the species was discovered in 1981, the Australian Wildlife Conservancy has said.

AWC Newhaven Wildlife Sanctuary wildlife ecologist Dr Tim Henderson said the first call of the species – that goes by the scientific name Uperoleia micromeles – was recorded in March by ecologists at the sanctuary about 350km northwest of Alice Springs, a week after record-breaking rains soaked some areas of the NT.

Dr Henderson said his team was excited to have made the first sound recording of the elusive species after the 316mm of rain that fell that month, filled the sanctuary’s ephemeral lakes and wetlands, triggering a flush of plant and animal activity and driving the frogs into a frenzy of courtship and breeding.

He said an app developed by the Australian Museum called FrogID was used to record the call via smartphone, which will help future detections.

“It’s not often that you get to document something like this for science for the first time,” Dr Henderson said.

“Over the Easter long weekend following all the rain, we visited one of the clay-pan lakes to look for frogs and see if we could track down the Tanami toadlet. Newhaven looked more like the Okavango delta than a desert.

“It was our third wettest month on record, and we’ve already received more than the annual average rainfall in 2024.The lake is extremely full at the moment, and while we were there we heard lots of frogs calling. The calls were distinctive, and unlike any of the other species we find here regularly.

“We were eventually able to pinpoint the calls through the undergrowth to locate these miniature frogs, which matched the description for Tanami toadlets.

“The FrogID app gives us an easy way of detecting and recording frogs that can be tricky to spot, or difficult to identify by appearance alone.”

FrogID lead scientist and Australian Museums amphibians curator Dr Jodi Rowley said she was also very excited to confirm the toadlet’s call.

“It’s taken 43 years since we first recognized this species for someone to record its call – that’s pretty amazing,” Dr Rowley said.

“There’s still so much to discover about Australian amphibians, and this recording will make it easier for other people to detect Tanami toadlets in the future.”

Dr Henderson said Tanami toadlets were first identified by scientists in 1981, grow to just four centimeters, and live across an unlikely expanse of country in the Tanami and Great Sandy Deserts, in the Northern Territory and Western Australia. It’s one of 28 small, inconspicuous frog species in the genus Uperoleia, commonly known as toadlets because of their bumpy skin, though they are not closely related to toads, he said.

An earlier genetic study of the genus Uperoleia showed that the species evolved around the same time as vast, arid dune fields spread across inland Australia. It’s closest relative lives in the monsoonal tropics, in the west of Kimberley, WA.

The app is free to download and designed to convert professional and amateur citizen scientists’ enthusiasm into valuable scientific data.