Discovering new species is a race against the clock. Though we know all manner of beasties are out there waiting to be discovered, whether or not we can find them before it’s too late is another matter. That’s why when researchers’ tireless efforts turn up 20 new frog species, it’s worth celebrating.
The crack team made up of international scientists have been wading through amphibious species of Madagascar in search of new names. They struck gold within the genus Mantidactylus, subgenus Brygoomantis. Before now, the group had just 14 members, but now has received a glut of 20 new members, and – according lead author Dr Mark Scherz, Curator of Herpetology at the Natural History Museum of Denmark – a lot of them sound like a creaking door or a gurgling stomach.
“Frogs can be very difficult to tell apart,” Scherz told IFLScience. You may recall him from the world’s tiniest reptile, or perhaps the artful species naming of some seriously small amphibians.
“We rely a lot on fine details,” he said, “like webbing patterns, ratios of certain measurements… and especially on the advertisement calls. Calls are used by females to both recognise members of the same species, and choose among potential mates, and as a result they evolve quickly and are often highly different between closely related species, even if those species look identical to our eyes.”
Using these characteristics, Scherz and his team were able to scan small, brown Brygoomantis frogs along streams in the humid forests of Madagascar. The group isn’t the easiest to spot, but their peculiar calls made things a little easier.
They were then able to pin down unique species from their finds with the aid of something called “museomics”. This uses DNA taken from museum collections – quite a feat considering that genetic material doesn’t usually stand the test of time well. By employing an approach called DNA Barcode Fishing, they were able to compare living specimens against old ones to reach definitive identifications.
Some favorites for Scherz included the new species Mantidactylus eulengergeri and M. brevirostris, which he described as having comically short snouts that make them look like caricatured frogs, rather than real animals.
The team believes there are still many Brygoomantis frogs out there that remain undiscovered, but with the aid of further field research and deeper dives into museum collections, they hope to grow the set. Sounds like hard work, right? But as Scherz told IFLScience, the job definitely has its perks
“Searching for frogs in Madagascar is always exciting. You often find yourself standing alone in the dark, up to your ankles (or knees) in water or mud, armed with a red head torch, an audio recorder, a camera, a notepad, and a plastic bag, trying your best not to move while the mosquitos and leeches take a tithe, with your ears pricked for the quiet calls of male frogs singing to attract a mate.”
“Sometimes the slightest disturbance may cause them to fall silent for an hour. But eventually, patience pays off, and you can find the calling male, and make a recording. A few minutes later, with the recording safely saved, you might dare to take a photo of the animal in situ. And then, finally, you can pounce, and, with any luck, catch the frog... It can be frustrating at times, but when it goes smoothly, you may be walking back to camp with a newly discovered species in-hand.”
The study was published in the journal Megataxa.