American pika (Ochotona princeps)

The American pika (Ochotona princeps) is a small mammal that is closely related to rabbits. They live in mountainous alpine terrain above 11,000 feet, preferring to take shelter from weather and predators in talus, the rockfall at the foot of mountains. Some examples of pika habitat in the Greater Yellowstone Ecosystem are Death Canyon and the Gros Ventre landslide.

Pikas have large, rounded ears, a discreet tail, and a grey-brown coat. Adults grow to be about six inches long, so they are difficult to spot as they are well camouflaged in the talus. However, pikas are easy to hear because their loud, high-pitched call draws attention quickly and alerts others to hide from predators.

Each female pika can have anywhere from two to six pups per litter—possibly two litters a season—and they live anywhere from three to seven years. Their diet consists of wildflowers, sedges, and grasses. After July, feeding activity increases to benefit from the new plant growth. Since they do not hibernate, pikas stockpile food into haystacks to dry and later place it in their burrows for winter. These mammals can eat highly toxic plants! Pikas place the poisonous plants at the bottom of their stockpile because the toxins help preserve the other plants being stored, and the poisonous plant becomes tolerable over time.

Pikas are active in the early mornings and later in the day because they need colder temperatures to survive—six hours of exposure to temperatures over 80℉ will kill the mammal. Pika populations have declined because warming climate is a threat to the most sensitive species in the ecosystem. They move upslope to escape warmer temperatures, forced to abandon their lower elevation homes and start living at higher elevations. Sadly, there is only so much mountain to climb. That is why pikas are the “canaries” of climate change.

Written by Celia Karim
PC: YNP on Flickr: https://flic.kr/p/28ZLLDy

Sources: https://www.nps.gov/romo/learn/nature/pikas.htm, http://www.biologicaldiversity.org/species/mammals/American_pika/natural_history.html  and Personal notes from ENR 1200 taught by Christopher Beltz, Fall 2016, University of Wyoming.

American Marten (Martes americana)

The American marten, also known as the pine marten, is a small, nocturnal member of the weasel family. Martens inhabit mature conifer forests in the northern parts of North America and down through much of the Rocky Mountains, including Grand Teton National Park. These feisty carnivores are frequent visitors to the station and spend their time rustling through the garbage bins. As opportunistic feeders, martens enjoy munching on anything from small animals like squirrels and frogs, to fruit and seeds, and will occasionally scavenge on carrion. Their favorite food, however, is red squirrels, and they will engage in high speed pursuits through the treetops to catch them.

Something rather unique about pine martens is that they utilize a reproductive method known as delayed implantation. Females breed with males from June to August, but the fertilized egg does not actually attach to the uterus and begin development until the following February, after which the gestation period is only 28 days. The youngsters are full grown by 3.5 months and begin having litters of their own by the time they reach 15-24 months old! Learn more about these magnificent mustelids here.

Written by Timothy Uttenhove
PC: YNP on Flickr

Bison (Bos bison)

These massive mammals are a sight to see in Grand Teton National Park (GTNP). Bison are North America’s largest land mammal, weighing up to 2,000 pounds if they’re male, similar to the size of a larger car. They can also reach up to 35-40 mph running speed, so be sure to steer clear of these majestic animals. A paper in Journal of Wilderness Medicine looked at injuries caused by animas from 1978-1992 that occurred in Yellowstone National Park, a close neighbor north of GTNP. According to the paper, on average, 3.73 people were injured by bison each year. Visitors are urged to keep a distance of at least 25 yards from wildlife and up to 100 yards in the case of large animals (National Park Service).

If you want to find bison in the park, be sure to keep an eye out in the flat grassland areas but remember to be cautious and keep your distance. Going north on highway 191, just past Cunningham Cabin, the scenery will open up to a flat grassland where there is normally a herd of bison and cattle. If you are also taking a trip to Yellowstone NP, be sure to visit Lamar Valley as well! Although an older post on NPS, check out https://www.nps.gov/grte/blogs/bison-a-summertime-visitor-countdown-29-days.htm to learn more of the life history of bison!

Written by Anna Cressman
PC: Anna Cressman

Boreal Toad (Anaxyrus boreas boreas)

The Boreal Toad (Anaxyrus boreas boreas) is a protected species in Wyoming that prefers mountainous areas at high elevations between 7,000-12,000 ft, and this pictured toad was found on the shore of Swan Lake in Grand Teton National Park (GTNP). Populations have been on the decline over the past 20 years due to chytrid fungus—an infectious fungus among amphibians that causes a deadly disease. The fungus is currently being studied all over Wyoming amphibious habitats and in other states that have listed the Boreal Toad as endangered, like Colorado and New Mexico. Specifically, in the Greater Yellowstone Ecosystem (GYE), their populations have declined since studies in the 1950s. There is enough concern that a genetic bank and translocation efforts for these little guys is held in the Colorado Parks and Wildlife’s Native Aquatic Species Restoration Facility.

Adult Boreal Toads can be anywhere from 2.5-4 inches long, and young toads often lack the distinct light-colored stripe down the middle of their back. Tadpoles hatch late May to late June when they will start their two-month transition to toadlets. Toad skin is rough and bumpy which is the opposite of a frog. Young Boreal Toads generally are diurnal, and adults are mostly nocturnal. During spring and summer, you might find Boreal Toads by water—preferably acidic water for breeding. In winter, they hibernate underground in burrows, but the rest of the year they spend about a fourth of their time burrowing and then the remainder living in forested areas. These toads live in both dry and wet areas when not breeding, but usually near water. If you are looking for a Boreal Toad during mating season and expect to hear a loud chorus call, you may not hear anything because males have no vocal sac that other amphibians attract females with. Instead, they can muster up quiet calls to say they are disturbed. People have compared their call to a tiny chirp!

Written by Celia Karim
PC: Anne Guzzo

Uinta ground squirrel (Spermophilus armatus)

Uinta ground squirrels are small, burrowing rodents found in mountainous sagebrush meadows in the western US. They occupy a small range, being found in southwest Montana, eastern Idaho, northern Utah, and western Wyoming. They will dig burrows in which they form colonies at very high densities. Along with these mountain meadows, they often frequent lawns and other irrigated areas. After coming out of hibernation, they begin the breeding season, where females will typically produce litters of 4-8 young at a time. Early summer is the perfect time to relax on the front porch of the Berol lodge and watch the younglings frolic about the lawn. These cute critters forage on green vegetation, seeds, and insects. They also enjoy aquatic plants and are surprisingly good swimmers!

While they are undoubtedly fun to watch, timing is key. Uinta ground squirrels are only active for about 3 months of the year, as they are in hibernation all winter before going dormant again in the late summer. Learn more about these rowdy rodents here.

Written by Timothy Uttenhove
PC: Timothy Uttenhove