The Hula painted frog was probably never common. The species, native to just a few small habitats in Israel, was only recorded by scientists on a couple of occasions, the first time in 1940 when two frogs were collected for study. (One of them ate the other in the lab.) One more specimen was collected in 1955. After that, nada. Pollution and development dried up the marshes where the frog had been seen, and it looked as if the species had disappeared as a result. The International Union for Conservation of Nature (IUCN) declared it likely extinct in 1988. After eight more years (and many searches) the organization finally declared it extinct, making it the first modern-day amphibian to be labeled as such by the IUCN.
But some people never gave up on the Hula painted frog; they kept looking, although the frog never revealed itself.
Until 2011, that is. Yoram Malka, a warden with Israel's Nature and Parks Authority, was patrolling the recently rehydrated Hula Nature Reserve looking for birds but also hoping that something unexpected would hop in front of his path. It did: "I saw something jump that didn't look familiar," Malka told the Israeli newspaper Haaretz in November 2011. "I rushed over and caught a frog, and when I turned it over I saw that it had a black belly with white spots, the identifying mark of the painted frog. I immediately returned [with it] to the reserve's office and took out the animal handbook, and I saw that what I had found look[ed] exactly like the painted frog that appears in the handbook."
Flash forward 19 months, and Malka is a co-author of a new paper describing the Hula painted frog, which was published June 4 in Nature Communications (Scientific American is part of Nature Publishing Group). The paper, "The rediscovered Hula painted frog is a living fossil," reclassifies the lost frog from the previous taxonomy of Discoglossus nigriventer (the genus of other painted frogs) to Latonia nigriventer, making it the only living member of that genus. All other Latonia species died out about 15,000 years ago. Researchers used genetic tests and CT scans to determine the new taxonomy.
Sarig Gafny, another co-author of the paper and a professor at the Ruppin Academic Center in Israel, told BBC News (one of many, many media outlets to cover the rediscovery this week) that researchers have found 13 more Hula frogs since the rediscovery. It wasn't an easy task, which probably indicates why finding the Hula frog took so long. "You have to crawl in the dense vegetation, there are blackberries there, which are spiny, and then you have to dig in the decaying detritus," he says. "It's not very attractive to go and look for it."
As the authors wrote in their paper, the survival of the Hula painted frog "is a striking example of resilience to severe habitat degradation during the past century by an amphibian." The researchers estimate there may be as many as 100 to 200 individuals in the reserve. That's not exactly a thriving population, but it's better than nothing.
Photo by Frank Glaw