By: Jayden Lu

On June 15, 2022, Richard Essner Jr, a zoologist at Southern Illinois University Edwardsville, found an explanation for why the pumpkin toadlet that live in southern Brazil, can leap into the air but has trouble landing. “I’ve looked at a lot of frogs and these are the weirdest things I’ve ever seen,” says Essner. The team he is in described its new analysis in Science Advances.

The frogs’ scientific name is Brachycephalus (Brack-ee-seh-FAAL-us). The frog is as small as your thumbnail, they can be tricky to find in the wild. Scientists listen for their high-pitched, buzzy calls. Then they scoop up leaves in the area, hoping to grab a few toadlets in the process.

When Essner saw videos of the pumpkin toadlet’s awkward air tricks, he was shocked. So shocked that he hopped on a plane to study animals with a research team in Brazil. In the lab, he and his team used slow motion video to record more than 100 tiny frog jumps. The clumsy tumbles suggest these toadlets had an issue tracking their bodies’ motion and position.

Typically, fluid sloshing through tubes in the inner ear helps animals sense their body’s position. But for the pumpkin toadlet their tubes are one of the smallest ever recorded for an adult vertebrate. Other studies had shown that the small tubes aren’t that good. So, the frog leap into flight. And because the tubs aren’t good the frog has a hard time figuring out how to land feet-first. A new study thinks this problem might trace back to structures in their inner ears.

It’s possible that bony back plates may offer some toadlets a bit of crash protection. But these animals may after all just stay grounded for safety. As Essner observed, these frogs are “almost always crawling really slowly.”