Weighing only a couple of grams, the Mount Lyell shrew is a tiny animal native to Yosemite National Park. Though the fast-moving, high-elevation critter has been known to biologists since the early 1900s, no one has managed to photograph one in the wild.
Until now.
An audacious team of student researchers affiliated with the California Academy of Sciences just announced that they captured a photo of the shrew after spending three nights in October trekking through the Eastern Sierra.
“We did some research and learned there was only one mammal species in California that appeared to have never been photographed alive,” said Vishal Subramanyan, a 22-year-old at UC Berkeley’s Department of Environmental Science, Policy, and Management who ventured to the mountains. “It has only ever been trapped a handful of times.”
Along with Prakrit Jain, a 20-year-old at Berkeley’s Department of Integrative Biology, Subramanyan was inspired to document the hard-to-find shrew after shooting animals on a field trip for a mammalogy class. Typically, Subramanyan focuses on large predators like mountain lions, while Jain chiefly studies arachnids, but the mystery of the elusive shrew was too tantalizing to pass up.
To find this missing piece of California biodiversity, the duo consulted scientists at UC Berkeley’s Museum of Vertebrate Zoology, who shared what limited field notes they had. It turned out it had been almost 20 years since anyone had seen a Mount Lyell shrew. Even then, there was doubt as to whether a researcher had ever seen one alive.
Although not listed under the federal Endangered Species Act, the shrews are classified by the state as “highly to extremely vulnerable” to climate change. Long-nosed, burrowing animals, they’re sometimes confused with mice but are not actually rodents. (They’re more like half-pint hedgehogs or miniature moles.)
To photograph a shrew, Subramanyan and Jain first had to trap one — which is hard enough, but keeping it alive is tougher. As a rule, Jain said, the smaller the mammal, the faster the metabolism. “They need constant food. If they don’t get food for a little while, or if they end up getting wet, they can die very quickly,” he said. Bait a trap by night with spiders or a tasty freshwater crustacean, and any shrews that fall in are likely to expire by morning.
So Subramanyan and Jain took a different approach. In arid Boulder Canyon, at around 7,000 feet in elevation, not far from Mono Lake, they dug about 150 small holes and put a smooth-sided cup with mealworms or cat food in each. These low-tech “pitfall traps” don’t require coverings, because shrews can’t climb out.
“I would love to say we spent three days waiting, and the shrew finally appeared at the last second,” Subramanyan said. “But we got the Mount Lyell within the first two hours.”
In fact, they got 18 shrews in all, at least six of which were Mount Lyells. (A few got away before they could snap pics.)
Differentiating one shrew species from another can require comparing teeth sizes, so Jain photographed them with a Canon EOS 7D with a 100-millimeter lens — “a very typical macro setup, nothing particularly unusual,” he said. They took small DNA samples of their quarry before releasing them.
They managed to document the Mount Lyell shrew without any fatalities and came back as heroes. Both UC Berkeley and the Academy of Sciences were “really, really happy,” Subramanyan said. “Nobody, not even us, really thought this was going to work, especially on our first try. It’s a species we know almost nothing about — and they’re really challenging to photograph, because it’s nearly impossible to get them to stop moving.”
But they shot enough photos to get a few non-blurry ones. Having earned these biological bragging rights, Subramanyan and Jain plan to mount further expeditions to photograph other poorly understood mammals and get a better sense of how they fit into the state’s ecology. It’s a laudable goal, but what about something more ambitious, like a jackalope? Or head to Olympic National Park in pursuit of Bigfoot?
“It’d be great to get the first photos of Sasquatch,” Jain said. “But there is another species of shrew from Washington that I believe has also not been photographed. So that would be a very exciting one to do.”