A 38-day expedition in the remote Alto Mayo region, where development threatens wild habitats, turned up one previously unknown animal after another.
In the summer of 2022, researchers trudged into the jungles of the Alto Mayo region of Peru in search of undiscovered creatures. This remote yet populous region had experienced significant deforestation, so the team didn’t expect to find much.
But on Day 1, the researchers discovered a new species of climbing salamander. “I was so excited,” said the leader of the expedition, Trond Larsen, who is senior director for biodiversity and ecosystem science at Conservation International, a nonprofit.
And the discoveries didn’t stop there. A new species of butterfly was discovered shortly after, followed by a new species of squirrel. Then came their most surprising find of all: a mouse that swims with webbed feet.
“Amphibious rodents are almost mythical to mammal experts,” Dr. Larsen said. “They’re one of the more rare groups of mammals in the world. I’ve been on so many expeditions where we’ve searched relentlessly for them and come up with nothing.”
During their 38-day expedition, Dr. Larsen and his team discovered 27 new species in Alto Mayo, including four mammals, eight fish, three amphibians and 10 butterflies. The team also found dozens of rare and endangered species, some not known to occur anywhere else on Earth.