California’s most elusive mammal photographed for the first time

January 27, 2025

A tiny, elusive mammal native to a small stretch of the Sierra Nevada has been photographed for the first time by a team led by UC Berkeley student researchers.

The Mount Lyell shrew (Sorex lyelli) is a minuscule mammal measuring 9 to 10 centimeters in length and weighing 2 to 3 grams. It inhabits a small, high-altitude region in the Eastern Sierra Nevada region, where it spends most of its time underground. The animal was identified by biologist Clinton Hart Merriam in 1902, but until recently, researchers had never photographed the animal alive—making it the only known mammal in California to lack photographic documentation.

Earlier this month, wildlife photographer Vishal Subramanyan, BS ’24 Ecosystem Management and Forestry; BA ’24 Statistics, and collaborators released the images they captured of the shrew in November 2024. The student researchers—who include Integrative Biology undergraduate Prakrit Jain, and University of Arizona student Harper Forbes—also produced a video in collaboration with the California Academy of Sciences, where Jain interns and Subramanyan is a part of the Academy’s first cohort of California Creators for Nature.

In a recent interview with SFGATE, Subramanyan and Jain said they got the idea to search for the shrew after trapping and photographing small rodents during a trip to the Sierra Nevada with their mammology class. After receiving permits from the California Department of Fish and Wildlife, the researchers set off for field sites near the unincorporated community of Lee Vining in the Eastern Sierra.

Over the course of three nights, the team deployed and monitored pitfall traps baited with cat food and mealworms. They captured shrews from four species, including the Mount Lyell shrew.

“It was kind of go, go, go,” Subramanyan told SFGATE. “You trap some shrews, you photograph them, you release them, and by that time there are more shrews. So it was pretty nonstop.” The team collected measurements and samples, collaborating with researchers at the UC Berkeley Museum of Vertebrate Zoology and Cal Academy to confirm the shrew’s identity. 

Although the Mount Lyell shrew is not considered an endangered species in California, the researchers hope to use photographs to raise awareness about its ecological importance. It is listed as a mammal species of special concern, facing threats from climate change to the 89% projected loss of its habitat by the 2080s. The researchers hope their work can inspire conservation efforts and public interest in the shrew’s survival.

Read More

Berkeley students capture first images of rare shrew

Subramanyan and Jain discuss their November expedition to capture on film and video a living Mount Lyell shrew, which had never before been recorded alive. Video by Patrick Farrell/UC Berkeley.