Scientists discover new mouse possum species in peru’s río abiseo national park during squirrel research expedition

What started as a quest to find an elusive squirrel species led to an unexpected discovery in one of Peru’s most biodiverse protected areas. In 2018, Brazilian biologist Silvia Pavan ventured into Río Abiseo National Park in Peru’s San Martín region, hoping to collect genetic samples from a mysterious squirrel species that had been identified decades earlier but never formally described or named.

The National Geographic-supported expedition took Pavan and her team into the park’s cloud forests, ecosystems known for harboring numerous endemic species found nowhere else on Earth. While they only glimpsed their target squirrel once during the entire expedition, the researchers made a remarkable consolation discovery: a previously unknown marsupial species they named Marmosa chachapoya.

This newly identified mouse possum was found living at an elevation of 8,740 feet in the park’s misty cloud forest habitat. The discovery highlights the incredible biodiversity that still remains undocumented in Peru’s protected wilderness areas, even in regions that scientists have studied for decades.

The find appears to be just the tip of the iceberg for Río Abiseo National Park. Pavan’s team encountered at least two other mammal species that appear to be new to science, and researchers are currently analyzing data to confirm these additional discoveries. The ongoing research underscores how much we still don’t know about the wildlife inhabiting South America’s remote mountain ecosystems, and suggests that many more species discoveries await in Peru’s protected cloud forests.