EDITOR’S NOTE: This article is part of a new MoJo series that goes beyond bison, bears and wolves to spotlight Yellowstone’s often-overlooked wildlife.
Near mountaintops across the West on a late summer day, a bird with distinct black and white wings swoops from tree to tree foraging for seeds. It may not look like it, but this Steller’s jay-sized bird is doing more than gathering food for winter — it’s supporting an entire ecosystem with every peck of its beak.
The bird is the Clark’s nutcracker. Shaped like a crow with a long, sharp bill, it’s named for renowned explorer and ornithologist William Clark, who first saw and documented it near the Columbia River during his famed expedition with Meriwether Lewis in the early 1800s. Clark named the bird Nucifraga columbiana, meaning “nutcracker of the Columbia.”
Found in the Rockies, Sierras and Cascades, Clark’s nutcrackers spend much of their time in subalpine areas, the space between dense forests at lower elevations and the treeless slopes of the alpine. They’re drawn to the meaty seeds of one of the few tree species to survive in the rugged terrain — whitebark pine.
Cracking the cones
Whitebark are distinct-looking trees. Standing up to 60 feet tall and 5 feet in diameter, they have grayish-colored bark, wind-twisted trunks, and 3-inch-long needles that fan out in clumps of five on outstretched branches.
In late summer, the trees produce purple-colored cones, containing up to 75 seeds each, according to the National Park Service. The cones are so hard and dense that Clark’s nutcrackers are the only birds strong enough to break them open. Despite the effort it takes, these nutcrackers don’t hesitate to get to the nutrient-dense seeds.
Perched on the trees, they use their sharp beaks to repeatedly hammer the cones until they crack, revealing the seeds inside. The birds discard the seeds they don’t want and appear to swallow the others — but they don’t eat them. Instead, they collect them in a pouch under their tongues.
Whitebark pine cones are so hard and dense that Clark’s nutcrackers are the only birds strong enough to break them open.
At peak harvest, Clark’s nutcrackers are easy to spot. Their feathers are often stained purple from the pinecones, and their throats are so full, holding up to 125 seeds at a time, they appear to have goiters, said Hillary Robison, deputy chief of Yellowstone National Park’s Center for Resources.
With a pouchful of seeds, the bird looks for a suitable place to cache, or bury, its bounty. Flying up to six miles away, the Clark’s divides its seeds among multiple caches, typically dropping between two and 12 seeds in each one, said Robison, who also leads the park’s whitebark pine program. All told, a single Clark’s nutcracker can bury up to 100,000 seeds in a good year, NPS reports.
Clark’s nutcrackers have incredible spatial memories, using landscape features, like downed trees or large boulders, to find their caches again in the winter when other food sources are scarce. But they don’t remember where every cache is located — and that’s a good thing for the ecosystem, Robison said.
Supporting the ecosystem
Whitebark pines don’t easily reproduce on their own. Unlike most pine trees, their cones do not open naturally, and even if they did, their wingless seeds wouldn’t travel more than a few feet. Left to chance, the species wouldn’t spread far.
That’s where Clark’s nutcrackers come in. Caching seeds across the subalpine terrain — and forgetting some of them — Clark’s are the arborists of the whitebark pine forest. Without them, the trees would struggle to regenerate or spread. The heat from wildfires can also open whitebark cones which are then spread by the bird. Whiteback pines are “completely dependent” on Clark’s nutcrackers, Robison said.
The relationship between Clark’s nutcrackers and whitebark pines is the foundation for an entire ecosystem. Nearly 20 animal species rely on whitebark pine for food. Among them are red squirrels, which cut down the cones and store them in middens, and endangered grizzly bears, which rely on the seeds (usually ones they dig up from the squirrels’ middens) as a primary food source.
Whitebark pines also trap and filter snow, playing an important role in water level and quality. According to Robison, everything — from fish and agriculture to water-based tourism — benefits. “Whitebark pine is a keystone species,” she explained. “It provides a lot of ecological services.”
Saving the Trees
Clark’s nutcrackers and whitebark pines have been linked for centuries. But conservationists have become especially interested in their relationship in recent years, as the trees have come under threat.
Beetle infestations and blister rust — an invasive fungus introduced through European lumber imports — have devasted the species, wiping out over 90 percent of trees in some areas, according to NPS. In 2022, the decline moved the U.S. Fish and Wildlife Service to list the trees as threatened under the Endangered Species Act.
Conservationists are now taking measures to save the trees. Their primary concern is blister rust, a disease that girdles trunks with cankers and ultimately starve trees to death. To combat it, they’re identifying disease-resistant trees and collecting their seeds.
From there, they follow one of two approaches: cultivating the seeds in a greenhouse and later transplanting the saplings (a laborious process) or sowing the seeds directly into the ground — much like the Clark’s nutcracker.
The saplings are doing well so far, Robison said, but it’s too early to tell if direct sowing will succeed. Either way, she added, conservationists can’t restore the forests alone — that work ultimately rests with the Clark’s nutcracker.
“We as people can’t do what they can do,” Robison said. “They’re going to have to do the heavy lifting.”
Want to learn more about the important relationship between Clark’s nutcrackers and whitebark pine? Check out this NPS video.
