Clark's Nutcracker Life History

Habitat

Clark’s Nutcrackers live in open coniferous forests in the western United States and southwestern Canada, at anywhere from 3,000 to 12,000 feet. Starting in early June, they become more abundant at higher elevations, in stands of shrubby whitebark or limber pine (sometimes mixed with fir, spruce, or other pines) with nearby creeks, small lakes, and moist meadows. In the fall, nutcrackers move down to lower elevations into forests of Jeffrey pine, pinyon-juniper, limber pine, southwestern white pine, bristlecone pine, ponderosa pine, or Douglas-fir, depending on which forests have the most available seeds.Back to top

Food

All year round, the staple food of a Clark Nutcracker’s diet is pine seeds, either fresh or stored. The nutcracker uses its long, sharp, sturdy bill to crack open closed, unripe pine cones and remove seeds from the cone scales. It shells seeds by cracking them in its bill or by holding them in its feet and hammering them. Between September and December it stores seeds to eat later, placing 30–150 seeds in the pouch under its tongue and carrying them to a spot nearby or up to 15 miles away. It digs a trench in the soil with its bill and puts a cluster of seeds inside before covering them up again, or it pushes individual seeds into gravelly soil, pumice, or crevices in wood. During the winter and spring, it relocates caches by remembering where they lie in relation to nearby objects like rocks, logs, and trees. Nutcrackers have such good memories that they can relocate seeds more than nine months after caching them, though their accuracy declines after about six months. They don’t recover all the seeds they bury, and it’s estimated that for some high-elevation pines, such as whitebark pine, virtually all the trees you can see on the landscape come from seeds planted by a nutcracker. Nutcrackers use cached seeds to feed both themselves and their young. Clark’s Nutcrackers also opportunistically eat insects and spiders, and small vertebrates such as other birds, ground squirrels, chipmunks, voles, toads, and carrion.Back to top

Nesting

Nest Placement

Nests are in forks of the outer branches of conifers such as pines, larches, junipers, spruces, and firs near seed stores from the previous fall. They are built on the leeward side of trees for shelter from the wind, and they are often poorly concealed. It’s not known how males or females contribute toward choosing nest sites.

Nest Description

Males and females both gather nest material and build the nest in 5–8 days. They bring twigs of Douglas-fir, juniper, or incense cedar to the nest at a rate of one twig every 3–4 minutes, sometimes collecting material from 500 yards or more from the nest. While the male stands lookout on a perch, the female weaves twigs into a platform 8–13 inches across, secured to small branches on a supporting limb. She makes a cup of rotten wood pulp about 4 inches across and 3 inches deep, and lines it with dried grass, fine strips of bark, moss, or animal hair, with a layer of mineral soil on the floor.

Nesting Facts

Behavior

Clark’s Nutcrackers are gregarious birds that typically travel in small flocks, calling back and forth with far-carrying, rolling calls. When flying from tree to tree they often undulate like a woodpecker, alternately flapping and holding their wings close to their sides. They spend much of their time in summer gathering pine seeds and burying them in caches to be used later in the year. One nutcracker may fly toward another that is harvesting or digging up stored seeds and try to take over the food by pushing the bird out of the way. Clark’s Nutcrackers are monogamous and pair bonds seem to last for many years, although this hasn’t been studied closely enough to be certain. Courting birds fly together with fast dives and swoops, feed each other, and may hold twigs in their bills. Pairs hold nesting territories, which they may defend by locking bills and claws with intruders. They nest as early as January or February, possibly so the young will be independent by late summer, when it’s time to start caching seeds. In late spring, family groups with newly fledged juveniles join together into loose flocks. The nutcrackers are almost always in groups, except while depositing or retrieving seed caches. Besides other members of their own species, they also forage with other birds and mammals, most of which defer to the dominant nutcrackers. Clark’s Nutcrackers mob Red-tailed Hawks, Cooper’s Hawks, Swainson’s Hawks, Golden Eagles, and Great Horned Owls. They seem to play by flying wildly in high winds as well as by provoking and chasing small raptors.Back to top

Conservation

Clark's Nutcracker populations appear to have experienced declines between 1966 and 2015, most notably in Washington, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 230,000, with 89% living in the U.S. and 11% in Canada. The species rates and 11 out of 20 on the Continental Concern Score. It is a U.S.-Canada Stewardship species. Clark's Nutcracker is not on the 2016 State of North America's Birds' Watch List. Local declines may be due to a pine beetle epidemic and the arrival of white pine blister rust, both of which kill the whitebark pines that many nutcrackers depend on. Limber pine and southwestern white pine face similar threats, while pinyon pine is declining as people clear land for cattle. Because Clark’s Nutcrackers live in fragile subalpine zones near the tops of mountains, they are one of the species most vulnerable to climate change: as temperatures warm, habitat zones are likely to shift upward in elevation, reducing the amount of subalpine habitat available on mountaintops.Back to top

Credits

Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.

Partners in Flight (2017). Avian Conservation Assessment Database. 2017.

Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2017). The North American Breeding Bird Survey, Results and Analysis 1966–2015. Version 2.07.2017. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.

Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.

Tomback, Diana F. (1998). Clark's Nutcracker (Nucifraga columbiana), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

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