Glover’s silkmoth (Hyalophora gloveri)

Glover’s silkmoth has a documented range within the Western United States as well as some areas of Canada. They are found in montane shrubland and riparian habitats. Glover’s silkmoth is one of the two largest moths in its family, Saturniidae. Depending on the region, the life cycle of these moths, from egg to adult, takes place during the months of April through September. Larvae are found feeding on leaves of birch trees, bitterbrush, and willows, and once they mature, they will feed on different types of woody plants and shrubs, including willows and Prunus species. As adults, these moths can grow up to 51-67 mm in length.

In Asia, some moths of the family Saturniidae are used in silk production. Silkmoth larvae do all the work in producing silk. When silkworms are ready to metamorphose, they spin their cocoon with raw silk. In another species of Hyalophora, the larvae (or caterpillar) take the summer months to mature, and as fall approaches, they spin their cocoons and spend the winter months in diapause during the pupal stage.

Written by Anna Cressman
PC: Anna Cressman

Great Grey Owl (Strix nebulosa)

Most people have probably heard of the Great Horned Owl, but have you ever heard of the Great Grey Owl? Great Grey Owls (Strix nebulosa) are less common in the GYE than Great Horned Owls, but they still inhabit the area so if you see them it is a treat! Compared to other owl species, Great Grey Owls are quite large; their wingspan reaches 5 ft in length, but they only weigh about 2-3 pounds. Novice birders can identify Great Grey Owls from other owls in the GYE because their face is surrounded by a large darker colored ring with a distinct “X” shape between their eyes. They have white, grey, and brown feather patterns with yellow eyes.

Great Grey Owls prefer mountainous areas with pine and fir forests that are usually 2,500-7,500 feet in elevation. Jackson Hole photographer and author, Daryl Hunter, suggests looking in trees around Spalding Bay Road, Moose/Wilson Road, and Spring Gulch Road by the Gros Ventre River for Great Grey Owls. If you are near a meadow or a clearing at dawn or dusk, you will have even greater luck seeing these guys roaming the treetops. They like open areas surrounded by trees because they will swoop down low with their silent feathers to grab small mammals in clearings, while being able to perch on trees as needed. Great Grey Owls are skilled at hunting small prey because their ears are in different spots. Uneven ear heights allow owls to hear sounds at different times which helps them locate prey accurately—they can hear and pinpoint tiny animals under snow!

Written by Celia Karim
PC: Anne Guzzo

Fine-spotted Snake River cutthroat trout (Oncorhynchus clarkii behnkei)

One of the five native species of cutthroat trout to Wyoming, these feisty fish are a popular target for anglers in the Greater Yellowstone Ecosystem (GYE). Their native range is actually quite small, only consisting of the Upper Snake River between Jackson Lake and Palisades Reservoir, including the Gros Ventre River. These trout can be distinguished from the other subspecies primarily based on the spotting pattern.  They are close relatives of the infamous Yellowstone cutthroat trout, and they look very similar aside from a small color difference and the size and color of the spots.  They are not distinguishable genetically, and this has led to some debate about whether they are a separate subspecies or not! Snake River cutthroats can grow to over 20 inches and 3 pounds and are known for putting up a vicious fight. This combination of size and spirit makes them a prized sport fish, and they are often stocked outside their native range for the enjoyment of anglers.  Learn more about these spectacular salmonids here: https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=892 and https://wgfd.wyo.gov/Fishing-and-Boating/Cutt-Slam#howto

Written by Timothy Uttenhove
PC: Bryant Olsen on Flickr https://www.flickr.com/photos/bryanto/4721942263/

Coyote (Canis Latrans)

They are so common in the US that they have earned many nicknames for themselves—song dog, American jackal, prairie wolf, brush wolf—but most people refer to them as coyotes (Canis Latrans). You may have noticed that coyotes don’t usually run around in packs and are typically alone or with one other coyote. You can hear their piercing howl at both dawn and dusk. In areas with less people, they will usually hunt during the day; in more populated areas, they tend to hunt more at night. They hunt small rodents, occasionally elk calves, birds—even large swans—and feed off dead carcasses. Adult coyotes reach a maximum height of 2 ft tall usually weighing 30-40 lbs—this stature allows them to run up to 40 mph! Their coat colors vary based on location and may be a combination of grey, tan, and reddish hues. Coyotes in the Greater Yellowstone Ecosystem (GYE) have grown used to humans because of the high visitor rate to the parks, which have become places they can get food scraps or even handouts. Park rangers urge tourists not to feed wildlife because it fosters a reliance on humans and can initiate animal aggression.

Coyote populations declined by about 50% after wildlife officials reintroduced wolves to the GYE in 1995. However, GYE coyotes are now beginning to adapt to life with wolves. Coyotes inhabit a much greater area than wolves, they are all over the US—including cities. The state of Wyoming considers coyotes vermin, and they can be shot or captured without any restriction. Evidence suggests that this negatively affects the ecosystems they are a part of. Coyotes are fun animals to watch roam the parks and maybe you can see them pounce for prey!

Written by Celia Karim
PC: Anne Guzzo

Yellow-bellied Marmots (Marmota flaviventris)

Yellow-bellied marmots are a relatively large species of rodent related to woodchucks. They can be seen sunning themselves on rocks or foraging in forests or alpine tundra habitats. They are incredibly adept at scrambling along sheer cliffs and will almost always be found near some sort of rocky outcropping. Catching a glimpse of a marmot shouldn’t be too difficult. Just get out and go for a hike in the park, and you will have a good chance to spot one. A favorite forage of marmots are lupines and columbines, both of which are readily available in the summer months in GRTE. Next time you stroll through the mountains you might just hear some of their whistles or chucks, used to communicate with neighbors!

Like many other animals, marmots are being negatively affected by warming temps due to climate change. Studies show that they come out of hibernation up to 23 days earlier than they did 50 years ago. Lack of good forage at these earlier dates makes it much less likely that they will survive after coming out of their den. If you want to learn more about these rock-dwelling rodents, look here: Wildlife Land Trust, “Yellow-Bellied Marmots.”

Written by Timothy Uttenhove
PC: Timothy Uttenhove

Red Fox (Vulpes vulpes)

Scientists estimate the red fox (Vulpes vulpes) inhabited North America somewhere between 2 million to 100,000 years ago. That is likely longer than humans lived here. This fox, the largest of all fox species, is found throughout the world because they easily adapt to environments. They have something called biological plasticity—there are 48 possible subspecies. The red fox you would find in the Greater Yellowstone Ecosystem is the Rocky Mountain red fox (Vulpes vulpes macroura); this specific fox typically has a lighter colored coat than most red foxes. Even though their name suggests they are red, these foxes can also be black, brown, or blonde, but usually have black legs and a white chest.

Red foxes live underground in dens that are up to 20 ft deep with multiple exits just in case a predator is on their tracks. Sometimes they will use preexisting burrows of small mammals and make them a little more spacious. Wolves will do the same to abandoned fox dens. Red fox kits are born in a litter of about 4 or more, and young foxes that are almost indistinguishable from adults. Young foxes tend to stay with their parents to help raise the new litter. Unlike humans, kits can find their own food at just 3 months old. A red fox family will stay together until fall, when their kits have learned how to hunt voles, mice, rabbits, birds, or other small critters on their own. When red foxes dive for prey, they catch their food 73% of the time—that’s skill! Citations and more to read: Yellowstone Natural History: Red Fox, and Daryl Hunter’s eBook, Grand Teton: Photography & Field Guide.

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

Grizzly Bear (Ursus arctos horribilis)

These towering behemoths stand as one of the biggest attractions for the 4 million visitors traveling through the park every year, and with good reason. At 8 feet tall and 800 pounds, grizzly bears are truly a spectacle to witness. Despite their reputation as fierce carnivores, devouring anything in their path, they are actually omnivores – most of their diet consists of berries, fruits, nuts, and leaves. You can see them early in the summer along the main road in the park, and they occasionally visit the station. While they once lived in most of western North America, and occasionally even spent time on the Great Plains, overhunting and habitat loss due to human development greatly reduced their population and range. Everywhere grizzlies reside, even within the park, conflict with humans becomes a consistent topic of discussion and tension. People getting attacked attempting to get that once-in-a-lifetime selfie or loss of livestock causes countless issues for wildlife management agencies and politicians.

Grizzly 399 (pictured here) is possibly the most famous bear in the world and a legend of Grand Teton National Park (GTNP). At 24 years of age, especially after losing her cubs to a roadside collision several years ago, people wonder every year how much longer she will survive. But this year, her ever-growing fan club was shocked to see her come out of hibernation with 4 cubs! To learn more about these unique ursids, read here.

Written by Timothy Uttenhove
PC: Anna Cressman

Rocky Mountain Elk (Cervus canadensis nelsoni)

Have you ever heard the eerie glissando of a male elk bugle in the fall? Fun fact: elk communicate extensively, and scientists are still trying to understand their complex language. There are tens of thousands of Rocky Mountain elk (Cervus canadensis nelsoni) wandering around the Greater Yellowstone Ecosystem (GYE); they are a current and historical food source as well as larger members of the deer family.

Elk are easy to spot in the GYE in winter when they travel to lower elevation to eat grass, forbs, and shrubs. A great way to spot an elk is to look for their white rump. During the summer, they hide away in the mountains to find some tasty tundra vegetation to munch on. Elk mostly eat early in the morning and late in the day so that they can digest their impressive intake of about 20 lbs of plants per day. Elk have dark legs and heads—males have a light brown body and females have a darker brown body. Only male elk have antlers that they grow each year and when their antlers are covered in velvet, they can grow up to an inch every day!

In the late 19^th and early 20^th centuries, thousands of elk died of starvation in winters with heavy snow that forced them to migrate to forage. Because settlers built cattle ranches in Jackson Hole, the elk migration path became too limited. Elk were so hungry they would even break into hay storage that was supposed to be for livestock. Because of these events, the National Elk Refuge began in 1912 to give elk 24,700 acres to forage native grasses for the winter.

Written by Celia Karim
PC: Anne Guzzo

Black bear (Ursus americanus)

Despite their reputation as predators, black bears mostly consume plant matter. They are opportunistic feeders, eating whatever they find – including berries, carrion, insects, and any delicious-smelling items they might find at a campsite. Signs are posted across GTNP, reminding visitors to “Be Bear Aware,” and practice habits that keep people and bears safe. When visiting, prevent scavenging and unwanted bear encounters by keeping food put away, sealed in bear-safe containers, and stored in places that bears cannot break into.

Both black bears and grizzlies inhabit the park and draw visitors from across the globe. Distinguishing the two goes beyond size and color, which can be misleading. Instead, when you find a bear, check for these distinguishing characteristics! Does it have a shoulder hump? A shoulder hump is a defining characteristic of grizzly bears – you won’t see it on a black bear. What shape is the snout? Black bears have a straight face from their forehead to their nose; grizzlies have a concave face. What do the tracks look like? Rounded prints are typical for black bears. Also, their claws are shorter and more curved, so the claw marks appear closer to the toe pads. Grizzly tracks are more square-shaped with claw marks to match their longer nails.

Written by Shawna Wolf
PC: YNP on Flickr https://flic.kr/p/oG7xrv

River Otter (Lontra canadensis)

The river otter has been navigating waterways in North America for quite some time, and the Greater Yellowstone Ecosystem (GYE) is home to the playful little fish eaters. These semi-aquatic mammals are pretty well adapted to water for being half land-dwellers: their eyes are near-sighted for underwater vision, their ears have water-tight flaps, their fur is water repellent and insulated, and they can stay underwater for 2 minutes. Otters eat whatever they can find living in the water when they hunt at night, but they especially love fish. In GYE lakes, otters prefer to eat cutthroat trout, and in rivers or streams they eat longnose suckers when cutthroat trout are not available. Since the introduction of lake trout to the GYE about 25 years ago, these native cutthroat trout populations that river otters depend on have been declining. This is problematic for otter populations because otters do not eat lake trout, so competition between invasive lake trout and cutthroat trout is resulting in their food becoming more limited.

River otters are quite social mammals that are tightly wound into the ecosystem. They live in burrows close to water with an opening above ground, but in winter the only available opening is into the water. They are inherently stealthy because they have both land and water predators, including humans who trapped them for their fur. Otters grow up to 30 pounds and just over 2 ft long, so their size helps them defend their large dens. The male otter typically does not help with raising pups. It’s often just the mom that raises the litter of 6 or less pups in underground dens, making sure they are ready to swim at just two months old. Otters tend to live in social groups; some groups are all related individuals, some are all unrelated males, and some are couples. They play games with each other, catch and release fish for sport, and talk to each other with whistles, chirps, chuckles, and growls—would you believe that they are considered shy? Even though they are active all year round, it is super lucky if you get to see them in many GYE waterways and lakes—common otter hangouts are Oxbow Bend and the Yellowstone River.

Written by Celia Karim
PC: Brian Gratwicke on Flickr. https://flic.kr/p/cXuY8j