Frogs have different accents, reveals new study

“Frog calls are really important, because it's actually one of the most accurate ways of identifying frogs, as frogs all have unique calls.”

“Think of it like an accent,” added Gillard. “But while we’re aware of the variation, we don’t really know why they can vary so much.” 

The work is important because frogs rely almost entirely on acoustic communication with each other. 

But where do the different accents come from? The acoustic adaptation hypothesis implies that animals communicating acoustically adapt their vocalizations to the local conditions to optimize transmission through their habitat. 

Testing a theory

The researchers set out to test this theory for banjo frogs.

“We saw there was a gap in frog research for this hypothesis,” said Gillard. 

“A lot of previous research with frogs was using really small-scale studies – often fewer than 100 individual frogs. So you can't really capture the full geographic diversity in frog call if you're not actually sampling that many frogs.”  

For their work, they made use of the FrogID project, an app developed by the Australian Museum, where citizen scientists can record the calls of frogs from around the country. 

“We had thousands of recordings of banjo frog calls at our fingertips. Using this data, we analyzed nearly 700 banjo frog calls from across their entire range, covering an area of over 1.7 million km2, from Tasmania to Far North Queensland, and everywhere in between,” explained Gillard.

Analysis revealed that the animals’ calls were not strongly related to habitat structure.

“Our findings have suggested that other factors may have a greater influence over the variation of banjo frog calls. It's likely going to be a combination of all different factors like more fine-scale features of the environment, acoustic competition from other frogs, and noise interference from wind, water, and other animals,” said Gillard. 

Now, the team is seeking to expand their research by looking at a variety of types of frogs.

“If we could do this research with different frog species with more complex calls, it might reveal more of a signal for habitat,” concluded Gillard in the statement.