27 New Species Discovered in Peru’s Alto Mayo Region, Highlighting the Area’s Rich Biodiversity

In a groundbreaking discovery, researchers in Peru's Alto Mayo region have identified 27 animal species previously unknown to science. During a 38-day expedition in 2022, researchers identified 27 species entirely new to science. 

The Alto Mayo, a mosaic of forests, agricultural zones, and Indigenous territories spanning 1.9 million acres, has long been under environmental pressure from deforestation and agricultural expansion. Yet, amidst this changing landscape, researchers were astonished by their findings.

“Discovering so many new species of mammals and vertebrates is really incredible, especially in such a human-influenced landscape,” said Dr. Trond Larsen, senior director at Conservation International and leader of the expedition. 

Among the newly discovered species were four mammals, eight fish, three amphibians and ten butterflies. Particularly captivating was an amphibious mouse with webbed toes, a rare semi-aquatic rodent species that Larsen described as having "an almost mythical status among mammal experts." 

Found in a single swamp forest patch now threatened by agricultural activities, the amphibious mouse is an urgent conservation priority. 

Equally remarkable was the “blob-headed fish,” a bristlemouth armored catfish with a peculiar, blob-like head structure. “The blob-headed fish has an incredibly bizarre head that looks almost like a giant swollen nose,” said Larsen. 

The function of this feature remains unknown, with theories ranging from sensory adaptations to foraging strategies. 

Adding to the intrigue, the dwarf squirrel—measuring just 14 cm in length and fitting easily in the palm of a hand—captured researchers' attention. Its chestnut-brown coloration and swift movements make it both elusive and endearing. Larsen noted, “It jumps quickly and hides in the trees.” 

Other discoveries included a spiny mouse with hedgehog-like guard hairs, a climbing salamander in a unique white sand forest, and new species of narrow-mouthed frogs and butterflies. 

This expedition was a collaborative effort with local Indigenous communities, including the Awajun people. 

“This Rapid Assessment allows the Awajun to protect our culture, natural resources, and our territory,” said Yulisa Tuwi, an Awajun woman who contributed to research on reptiles and amphibians. 

Tuwi emphasized how the findings align with the Awajun cosmovision, deepening their understanding of interconnected ecosystems. 

Larsen while acknowledging the importance of local familiarity said, “(The Awajun) have extensive traditional knowledge about the forests, animals, and plants they live side-by-side with.” 

Their contributions were vital in identifying species that were "new to science" but familiar to the community. 

The Alto Mayo landscape supports over 280,000 people and is home to 49 species listed as threatened by the International Union for Conservation of Nature (IUCN), including critically endangered monkeys and endangered birds. The findings underscore the urgency of implementing conservation measures to protect these ecosystems. 

“Our main goal is to provide scientific knowledge needed to move conservation forward in a way that works for nature and people,” Larsen stated. He warned that time is limited to meet global biodiversity goals.