California – The scientist walks with difficulty towards a pond with rubber boots, but does not enter the water. Instead, Brad Hollingsworth is shown on the swampy edge and recovers a recording device the size of a card deck. Then it opens it and extracts a small memory card that contains 18 hours of sound.
Back in his office in the Natural History Museum of San Diego, the herpetologist, an expert in reptiles and amphibians, uses artificial intelligence to analyze the card data. In three minutes, he knows that a large number of animals visit the pond, where native red -legged frogs were reintroduced after disappearing largely in southern California. There were owl ululatos, pecking carpenters, howls of coyotes and arbing frog songs. But there were no graznidos of the invasive bull frog, which has decimated the native population of red -legged frogs during the last century.
It was another good day in his efforts to increase the population of the frog of red legs and restore an ecosystem that covers the border between the United States and Mexico. The efforts occur while Donald Trump’s administration builds more walls along the border, which generates concern about the impact on wildlife.
The decrease in red leg frog
With a length of 2 to 5 inches, red -legged frogs are the largest native frogs in the west and once found themselves in abundance along the Coast of California and even Baja California in Mexico.
It is widely believed that the species is the star of Mark Twain’s story of 1865, “The Celebrated Jumping Frog of Calaveras County”, and its crimson hind legs ate during the gold fever. But as the frog of red legs decreased in number, the Toro frog, with its even larger hind legs, was introduced into the menus during the boom of California growth at the end of the 19th and early twentieth centuries.
The population of red -legged frogs was decimated by the insatiable appetite of the Toro frogs and the disease that brought the non -native species, but also because it lost much of its habitat due to drought and human development in the form of housing, dams and more.
Hollingsworth could not estimate the number of frogs of red legs that remain, but said they have disappeared from 95% of their historical distribution area in southern California.
Robert Fisher, of the Research and Monitoring Initiative Program of the United States Geological Service, looked for the frog for decades over about 250 miles from Los Angeles to the border. He found only one in 2001 and none after that.
The scientists who used DNA of red -legged frogs captured in southern California before their disappearance discovered that they were genetically more similar to the population of Mexico than to anyone who was still found in California.
Anfibia diplomacy
In 2006, Fisher, Hollingsworth and others visited Baja, where they had heard of a small population of red -legged frogs. Anny Peralta, then a Hollingsworth student at San Diego State University, joined them. They found about 20 frogs and Peralta was inspired to dedicate their lives to their recovery.
Peralta and her husband established the Northwest Fauna Fauna Organization in Ensenada, Mexico, which aims to promote the proper management of natural resources. In 2018, they began building ponds in Mexico to increase the population of frogs that would then provide eggs to repopulate the species on the other side of the border.
But just when they prepared to move the egg masses, he hit the Covid-19 pandemic. Peralta and the United States scientists hastened to obtain permits for the unusual load and a pilot to fly the two egg refrigerators closer to the border. The rest of his journey north was by road, after the eggs passed an inspection of the United States Border Guard.
During the last five years, Hollingsworth and his team have sought sounds to show that their efforts to repopulate the ponds in southern California worked.
On January 30, he heard the quiet and distinctive grunt of the reproduction song of the red leg frog in an audio indicated by artificial intelligence.
“He felt like a great load removed from my shoulders because we thought the project could be failing,” said Hollingsworth. “And then, the following nights we start listening more and more and more, and more, and more.”
During the next two months, two males were heard singing in the 11 microphone in one of the ponds. In March, just below the microphone, the first mass of eggs was found, which shows that they had not only hatched from the eggs brought from Mexico, but also had produced their own eggs in the United States.
The role of artificial intelligence
Conservationists increasingly resort to artificial intelligence to monitor animals on the edge of extinction, trace the reproduction of reintroduced species and collect data on the impact of climate change and other threats.
Herpetologists are taking advantage of the tools driven by AI that are already used to analyze bird sound sets, hoping that you can help build audio landscapes to identify amphibians and track their behavior and reproduction patterns, said Zachary Prince of The Nature Conservancywho is working with the museum in the Ruba Rana project. The tools could also help scientists analyze tens of thousands of audio files collected in universities, museums and other institutions.
Scientists who work to restore the population of red -legged frogs in southern California expect them to soon be provided with satellite technology to send audio recordings to their phones in real time, so that they can act immediately if predators are detected, particularly bull frogs.
It could also help track the movement of frogs, which can be difficult to find in nature, especially because cold blood creatures cannot be detected by thermal images.
The artificial intelligence analysis of the audio of the pond has saved time to Hollingsworth and the others, which previously had to listen carefully innumerable hours of audio files to detect the songs of the frog of red legs, which resembles the sound of a thumb rubbed against a globe, on the cacophony of other animals.
“There are army frogs singing, there are cows, a road nearby with a motorcycle that comes and goes,” said Hollingsworth on the sound landscape of the ponds. “There are owls, there are ducks splashing, just all this noise.”
Building a binational frog population
The frog of red legs is the last species to see the success of binational cooperation along the border of almost 2,000 miles that California, Arizona, New Mexico and Texas covers. Over the years, the Mexican gray wolves have returned to their area of historical distribution in the southwest of the United States and in Mexico, while the California condor now rises over the heavens from fall to northern California.
According to the last count, scientists estimate that there are more than 100 adult red -legged frogs in the ponds in southern California, and reborn were spotted in a new site.
The team plans to continue transporting egg masses from low, where the population has increased from 20 to 400 adult frogs, hoping to build prosperous populations on both sides of the border. Sites are already seeing less mosquitoes that can transmit diseases such as dengue and zika.
A restoration pond on the decline that the Peralta organization recently built of small frogs, with its small eyes floating on its aquatic surface covered with ferns. They could, someday, put eggs for transfer to the United States.
“They don’t know anything about borders, visas or passports,” Peralta on frogs said. “This is just their habitat and these populations need to reconnect. I think this shows that we can restore this ecosystem.”