This was discovered by researchers from the Australian National University and the citizen science program ACT Frogwatch​, with volunteer data gathered over 13 years.

Dr Martin Westgate, a postdoctoral fellow at the ANU's Fenner School of Environment and Society was concerned about frog populations in the ACT when he started the research, as Canberra had already lost three species of frogs, but he was surprised to uncover the good news.

"There was concern that over time we could continue to lose frogs but the really clear pattern from our analysis is that this hasn't happened," Dr Westgate said.

Eight of the nine species commonly found in Canberra's ponds were studied across 320 wetlands and on more than 3,500 visits since 2002.

"But of the eight species studied, four are increasing in the ACT, and one of these four, the whistling tree frog, is increasing rapidly," Dr Westgate said.

Frog species have been going extinct around the country and the world due to a fungus-induced infectious disease called Chytridiomycosis​.

But a lot of work has been done in Canberra to help frogs, which could help explain their good health.

"All of the new suburbs in the north have what's called water sensitive urban design so they have wetlands or keep water in the landscape and that's providing a lot of habitat for frogs," Dr Westgate said.

"But urbanisation can be bad for frogs and we are going to keep expanding Canberra, so we need to make sure the new suburbs continue to have the occasional pond, wetland and park."

Collecting this much data  was made possible by the many ACT Frogwatch volunteers. Over 13 years, families visited wetlands and made recordings of the frogs.

The researchers also used satellite data from 2002 to 2015 to measure urban density.

"It has been a community effort and we are really thrilled that people are interested in frogs and that they are continued to engage with the Frogwatch program," Dr Westgate said.