How would you go about tracking these frogs?
You can see how tiny they are when you compare one of the frogs to a leaf visible in one of the images (top left or top right).
The answer to the question, as you may have guessed, are frog pants (or G-strings).
Sheena Goodyear’s June 13, 2023 article for the CBC’s (Canadian Broadcasting Corporation) As It Happens radio show explores the question and the research and includes an embedded 6:20 radio interview with researcher, Andrius Pašukonis,
How do you track a bunch of teeny-weeny frogs across the vast rainforests of South America? By putting teeny-weeny trackers on their teeny-weeny underwear, of course.
Biologist Andrius Pašukonis and his colleagues wanted to study the navigational capabilities of poisonous frogs that are too small for most animal tracking devices.
So he designed a Speedo-like harness that wraps around their back legs and props a tiny radio tracker on their backsides. The research team dubbed the invention “frog pants” — though Pašukonis says that’s “a bit of a misnomer.”
“My French colleagues like to call it a telemetric G-string,” Pašukonis, a senior scientist at Lithuania’s Vilnius University, told As It Happens host Nil Köksal.
“It’s a lot of fine motor skills and a lot of practice in handling tiny frogs and sewing little frog harnesses. But we go find them in the rainforest, and we catch them, and we put the tags on.”
My favourite part is “… sewing little frog harnesses.” Note: The following video features a commercial and then, moves onto a 2:22 interview,
More from Goodyear’s June 13, 2023 article, Note: A link has been removed,
Pašukonis was a PhD student at the University of Vienna when he first started experimenting with the frog pants design, and later put it to use while working as a postdoctoral fellow at Stanford University in California.
He and is colleagues used the tracker pants to study the spatial skills of three frog species that range from three to five centimetres in length — diablito poison frogs in Ecuador, and brilliant-thighed poison frogs and dyeing poison frogs in French Guiana. The findings were published late last year in the journal e-Life [sic].
“The only way to study movements of animals is to be able to track them and follow them around, which nobody has managed to do or even tried to do with these tiny, tiny frogs in the rainforest,” he said.
“So that became my goal and challenge, where I spent a good part of my PhD trying different versions of different tags and different attachment methods, trial and error, to finally get to be able to put tags on and track them and study their behaviour.”
The frogs, he admits, didn’t particularly like the pants. But they didn’t seem to mind too much, and the team removed the trackers after four to six days.
“Like any animal, they might scratch a little bit afterwards … like a dog with a new collar,” he said. “And then they just go on with their business.”
Other scientists have tried to track tiny frogs, from Goodyear’s June 13, 2023 article, Note: Links have been removed,
The design caught the eye of Richard Essner, a biologist at Southern Illinois University Edwardsville who studies animal locomotion, and has a particular interest in little frogs.
“Tracking small frogs with radio telemetry is not an easy thing to do,” Essner, who wasn’t involved in the Stanford research, told CBC in an email.
About a decade ago, he says his lab attempted to use radio telemetry to track the movement of the threatened Illinois chorus frog using a transmitter attached via an elastic belt around the waist.
“Unfortunately, we had to abandon the study because we found that the transmitter apparatus was interfering with locomotion. If the belt was too tight, it caused abrasion. If it was too loose it slid down around the legs and left the frog immobilized and vulnerable to predation,” he said.
The frog pants, he says, seem to offer a solution to this conundrum.
Lea Randall, a Calgary Zoo and Wilder Institute ecologist who specializes in amphibians and reptiles, ran into similar obstacles while trying to track northern leopard frogs at a reintroduction site in B.C.
Like the Stanford researchers, her team experimented with several different designs before landing on one that worked — a belt-like attachment with some “very stylish” smooth glass beads to prevent abrasion.
“Unfortunately, due to the weight of the radio transmitters at the time we couldn’t study smaller individuals,” she said.
“We didn’t use leg straps, but I can see the advantages of that to help keep the transmitters in place. The creative thinking and problem solving that goes into developing these kinds of studies always amazes me.”
Finally, frogs may be smarter than we think, from Goodyear’s June 13, 2023 article,
When it comes to animal cognition and behaviour, Pašukonis says frogs are understudied — and he believes, underestimated — compared to birds and mammals.
The poisonous rainforest frogs, he says, may be only a few centimetres in size, but when they breed, they carry their tadpoles between 200 to 300 metres across the rainforest to find them the perfect puddle to grow in.
Then they turn right around, and make their way home again.
“How could a little frog — frogs typically are not thought to be very smart — learn to navigate on such a big scale? And how do they find their way around more on a fundamental scientific level?” Pašukonis said.
“We’re uncovering that overall amphibians, for example, might be smarter or have more complicated cognitive abilities than we thought.”
Here’s a link to and a citation for the paper published by Pašukonis and his colleagues,
Contrasting parental roles shape sex differences in poison frog space use but not navigational performance by Andrius Pašukonis, Shirley Jennifer Serrano-Rojas, Marie-Therese Fischer, Matthias-Claudio Loretto, Daniel A Shaykevich, Bibiana Rojas, Max Ringler, Alexandre B Roland, Alejandro Marcillo-Lara, Eva Ringler, Camilo Rodríguez, Luis A Coloma, Lauren A O’Connell. eLife DOI: https://doi.org/10.7554/eLife.80483 Version of Record Published: Nov 15, 2022
This paper appears to be open access.