Yosemite National Park's approximately 90 mammal species, and their behaviors, are truly fascinating for park visitors to observe safely and responsibly. Seventeen mammals have a special status by either the federal or California state governments due to declining population numbers or to a lack of information about their numbers and distribution. Ongoing research has put a magnifying lens on several mammal species within the park and continues to build on work in the 1920s by famous mammal researcher Joseph Grinnell.

Black bear in Yosemite meadow
Black bears

American black bears found in Yosemite have long been of intense interest to park visitors and managers.

Sierra Nevada Bighorn Sheep getting released in Yosemite.
Sierra Nevada bighorn sheep

Sierra Nevada bighorn sheep are once again at home in Yosemite's supremely beautiful Cathedral Range after an absence of over 100 years.

Sierra Nevada red fox in snow caught on a wildlife camera.
Sierra Nevada Red Fox

A photo of a red fox padding atop a crest of snow in the far northern wilderness of Yosemite was proof that this creature is still alive.

Pacific fisher after being released in Yosemite peering over a log.
Pacific Fisher

Yosemite's wildlife staff have deployed motion-activated cameras in targeted locations to learn more about fishers and help them survive.

Mountain caught on wildlife camera during the day
Mountain Lions

Mountain lions—also called cougars, pumas or panthers—roam Yosemite’s mountains and valleys and are a natural part of the landscape.

Spotted bat on someone's hand

Yosemite is home to 17 species of bats, the only mammals capable of flight.

Mule deer in Yosemite Valley
Mule deer


In Yosemite Valley, mule deer are especially common, seen browsing on leaves and tender twigs from trees, grass, and herbs. Male mule deer grow antlers each year and are a factor in the dominance hierarchy among males, both visually, and in jousting among males for mating access to females. Although they seem disinterested in humans, deer should be treated as any other wild animal. Human injuries can occur from people offering food to deer or any other wild animal. More injuries in Yosemite are inflicted by deer, with one documented death, than those caused by black bear or any other park animal. Additionally, human food is not healthy for wild animals, and it is illegal to feed any animal in the park.

Some mammals are difficult to see due to their nocturnal habits. On the top of that list are the 17 bat species dining each evening on insects in Yosemite. They find food by emitting a high-frequency call and using their sensitive hearing to detect echoes
Golden-mantled ground squirrel eating acorns in fall.


Rodents comprise the highest proportion of Yosemite's mammals species. The oft-sighted squirrels species are in the rodent order, with other members: mice, gophers, and chipmunks. It's worth taking a moment to learn the four common squirrels visitors are most likely to see. The Western gray squirrel is gray with a long bushy tail and spends much of its time in trees. The Douglas squirrel (or chickaree) is a reddish tree squirrel that chews on pine cones and commonly squeaks. The golden-mantled ground squirrel looks similar to a chipmunk because it has stripes on its back (though, is larger), and the California ground squirrel-the most commonly seen squirrel in Yosemite-is brown, with white specks, and lives in burrows in the ground. The largest native rodent of the Sierra Nevada to watch for is the yellow-bellied marmot, found at higher elevations, like Olmsted Point on the Tioga Road, often sunning itself on rocks. This 5-pound mammal looks similar (and is related) to a woodchuck.

Last updated: February 13, 2017

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