A UNSW and Australian Museum study using data from a citizen science projectfinds 70 per cent of frogs are vulnerable to housing, agriculture, roadsand recreation.


We urgently need to consider human impacts on the environment, say UNSWSydney and Australian Museum scientists, whose study of 87 Australian frogspecies found almost three-quarters were intolerant of modified habitats.

The findings, published in the journal Global Change Biology, areparticularly concerning as more than 40 of Australia’s 243 frog species arealready threatened with extinction.

“Frogs need to be prioritised in urban planning and conservation decisions,”lead author and PhD candidate Gracie Liu from UNSW Science’s School ofBiological, Earth and Environmental Sciences says.

“By studying how species respond to human-driven habitat modification, andranking them based on their tolerance, we can prioritise the most vulnerablespecies and take appropriate conservation measures to mitigate the risk tobiodiversity.”

Frogs are the sign of a healthy environment, but they are one of the mostthreatened groups of animals on earth. Humans have played a large part intheir decline by clearing and modifying native vegetation for housing,agriculture, roads, and recreation. In Australia, cities and agriculturealready account for more than half of the country’s land use.

With this in mind, the researchers developed a tolerance index to measurethese effects on frogs, accounting for the multiple stressors such as roads,built up areas, farms, mines, and light pollution.

The index was based on over 126,000 frog observations from the AustralianMuseum’s citizen science project FrogID, which was set up to monitor frogpopulations and help better understand and conserve Australia’s frog species.

“Thanks to thousands of people across Australia recording frogs on theirmobile phones using the FrogID app, we had access to a huge number of frogobservations,” UNSW co-author and lead scientist of FrogID, Dr Jodi Rowleysays. Dr Rowley is also curator of Amphibian and Reptile Conservation Biologyat the Australian Museum. “A dataset of this size grants us the ability tostudy broad trends in terms of what makes a frog tolerant or intolerant.”

Alarmingly, 70 per cent of frogs studied were intolerant of human modifiedhabitats.

“Frogs that are so called ‘habitat specialists’ are particularly vulnerable tohuman impacts,” Ms Liu says.

“These frogs, including the Crawling Toadlet ( Pseudophryne guentheri ) andthe Bleating Froglet ( Crinia pseudinsignifera ), have specific habitatrequirements that backyards, gardens and other human modified habitats justcan’t provide.

“Frogs that lay their eggs on land are also intolerant of habitat modificationdue to their strong dependence on forest resources, so there is a clear needto preserve natural habitat.”

But other species, the ‘tolerators’, regularly turn up in people’s backyardsand may actually be perfectly content living there, the scientists say.

“Generalists species like the Striped Marsh Frog ( Limnodynastes peronii ),White-lipped Tree Frog ( Litoria infrafrenata ) and Motorbike Frog (Litoria moorei ) can make use of a variety of resources and environmentalconditions and can thrive in human modified habitats,” Ms Liu says.

The findings were optimistic for some frog species, with species that callfrom vegetation often tolerant of modified habitats.

“This suggests that in addition to preserving native habitat, frog diversitycan be supported by creating greenspaces and ‘frog-friendly’ gardens inmodified areas,” Dr Rowley says.

The scientists say many more species may be hard hit if stronger conservationmeasures are not taken.

Ms Liu’s next research will explore how habitat modification affects frogbreeding seasons, movements and habitat use.

The public is being encouraged to continue the count of Australia’s frogsusing FrogID so UNSW and Australian Museum scientists can continue to betterunderstand Australia’s frogs, the health of our ecosystems and biodiversity ingeneral.

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