May Wildlife Whereabouts: Migration, Nesting, & New Life

While May weather fluctuates, the season shifts perceptibly toward summer with warming temperatures and burgeoning vegetation. Park wildlife benefit from increasing food availability, which is especially vital for pregnant and nursing females. Spring is a time of heightened activity as many animals give birth and raise young.

Migratory birds, like osprey, American robins, mountain bluebirds, meadowlarks, and red-wing blackbirds are returning to Jackson Hole after migrating south for the winter. They are all busily engaged in courtship, nest building, and raising young.

Sandhill cranes, another migratory species, mate for life and often return to the same nesting sites year after year. As they arrive in the valley, they are especially vocal, practicing unison calling to strengthen pair bonds. They build mound nests and share incubation duties.

Wild canids, including wolves, foxes, and coyotes, are active around den sites as they care for pups and kits that will soon begin venturing out on their first exploratory outings.

Native cutthroat trout begin spawning in creeks and tributaries as water levels rise with spring runoff.

Ungulates have migrated to newly green meadows where the spouting plants provide important nutrition for expectant and nursing mothers. Moose and elk calving seasons are underway. Bison calves, born in April or early May, are a little older and growing steadily stronger.

Bears are out of their dens and active throughout the park. The last bears to emerge, female grizzly and black bears with cubs, are now on the move. Mothers with cubs-of-the-year make only small movements so their tiny cubs can keep up. In recent weeks, bears have made increasingly frequent appearances, delighting park visitors.

Grizzly bears are often easier to spot this time of year as they forage for early-season plants and dig for tubers and bulbs in open meadows. Carry bear spray and make noise while hiking to avoid startling a bear and triggering a defensive response.

Smaller park residents like the Uinta ground squirrels, badgers, and boreal chorus frog are also engaged in breeding activities and raising young, though they are less often noticed. Seeing these or any young animals in Grand Teton can be a special experience.

As wildlife rear their young, it is critical to give animals plenty of space. Nesting raptors may issue alarm calls when people approach their nests too closely. Bears, moose, bison, and elk are especially protective of their young and might pose a danger to people they perceive as a threat. If you elicit a raptor’s alarm call or experience any kind of vigilance or aggression from any animal, you are too close!