Nutcrackers and Squirrels, Farmers of the Forests

Nutcrackers and Squirrels, Farmers of the Forests

Clark’s Nutcracker
Nucifraga columbiana
Courtesy US FWS
Dave Menke, Photographer

Nutcrackers and Squirrels, Farmers of the Forests
Red Squirrel
Tamiasciurus hudsonicus
Courtesy US FWS
Donna Dewhurst, Photographer

Hi, this is Mark Larese-Casanova from the Utah Master Naturalist Program at Utah State University Extension.

Throughout Utah’s forests, many plants and animals take advantage of other organisms to survive. Whether it is a caterpillar eating a tree leaf, mistletoe growing on a juniper branch, or an owl catching a mouse to eat, one organism being consumed by another is almost inevitable. However, some organisms may inadvertently help others not only survive, but also increase their range.

Many conifer trees, including pines, spruces, and firs, depend on fungi that live in and around their roots. The fine fibers of the fungi act as root hairs, helping trees better absorb water and nutrients from the soil. Some fungi also have symbiotic relationships with bacteria that are able to take Nitrogen from the air and turn it into ammonia, which is one of the forms of nitrogen that helps plants grow. Conifer trees reproduce via seeds from their cones, and fungi produce mushrooms to release spores. Squirrels happen to find conifer seeds and mushrooms particularly tasty, and will readily eat them. As squirrels are known to do, extra food is cached away for winter, and some seeds and mushrooms are inevitably forgotten. This helps disperse seeds and spores, aiding in population growth. So, the fungus helps the tree grow, the tree and fungus provide food for the squirrel, and the squirrel helps the tree and fungus spread to new areas.

The Clark’s nutcracker, a bird closely related to the crow and raven, is also particularly important in aiding in the spread of pine trees. Living at higher elevations, nutcrackers must store food for the long winters on Utah’s mountains. A nutcracker’s stout beak is used to crack open pine cones to retrieve the seeds inside. It stores seeds in a pouch under its tongue, and flies away to cache the seeds for winter. Each Clark’s nutcracker stores tens of thousands of seeds every year. While many seed caches are found and eaten, some are forgotten and germinate into young saplings.

So, while squirrels and nutcrackers are ultimately just looking for a good meal, both play a crucial role in establishing and maintaining healthy forest ecosystems in Utah’s mountains. For Wild About Utah, I’m Mark Larese-Casanova.

For Wild About Utah, I’m Mark Larese-Casanova.

Images: Courtesy US FWS
Text:     Mark Larese-Casanova, Utah Master Naturalist Program
            at Utah State University Extension.

Additional Reading:

Cornell Lab of Ornithology. Clark’s nutcracker.

Larese-Casanova, M. Utah Master Naturalist Mountains Wildlife Field Guide. Utah State University Extension. 2012.

Maser, C., and Z. Maser. 1988. Interactions among squirrels, micorrhizal fungi, and coniferous forests in Oregon. The Great Basin Naturalist 48(3):358-369.

US Forest Service. Clark’s Nutcracker.

Washington Department of Fish and Wildlife. Living with Wildlife: tree squirrels.

Cache and Retrieve

Clark’s Nutcracker
Nucifraga columbiana

Courtesy Steven Pavlov
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license

Common Raven
Corvus corax

Courtesy US FWS
Gary M. Stolz, Photographer

Hi I’m Holly Strand.

Every year, just before Christmas, I comb through the house looking for presents hidden earlier in the year. I check inside old shoes, unfold towels in the closet, and peer way back into the dark recesses of seldomly-used cabinets. With a child in the house, you have to be tricky! The problem with this complex gift stashing behavior is that sometimes I forget where I hid the present when it’s time to wrap it! And once in awhile I forget that I bought something at all! Out of sight—out of mind!

You wouldn’t make a very good magpie, I have been told. For magpies– along with jays, crows and ravens, are masters at hiding–or caching as it’s called– and then retrieving. Of course, what they cache is not Christmas presents but food.

One Utah bird that is much admired for its caching and retrieving skills is Clark’s nutcracker . This large jay lives in mountainous areas throughout the west. Experts say that Clark’s nutcracker can cache 10s of thousands of pinyon, whitebark or limber pine seeds in a single season. Starting in August, the bird will hide 1-15 seeds at a time, often distributing them several kilometers and at much different elevations from the original tree. Caches lie 1-3 centimeters deep in forest litter, bare soil, under bark, in holes, in logs or stumps.

As winter wears on, the nutcracker will retrieve its caches with the help of visual landmarks such as rocks, trees or logs. Using these visual cues, the nutcracker will retrieve the seeds through summer of the following year. Forgotten or abandoned seed caches often germinate, growing into trees that produce more food.

Just as I worry about prying eyes when I hide Christmas presents, birds who cache must be careful to notice who is watching. The common raven is notorious for its spying and thieving behavior. One raven will covertly observe while another caches scraps of meat, eggs, bones or seeds. The observer will then shamelessly raid the cache usually within a couple of days. But having probably raided someone else at some point, the caching raven is on the lookout too. If the caching raven senses the presence of a would-be looter, it might wait for the other bird to become preoccupied. Or it may move the food to a different site altogether. Caching ravens will also hide behind some structure to avoid being seen.

Interestingly, these sly birds will even engage in fake caching. Ravens will cache inedible or low value food items in plain view of other ravens but then stash the good stuff in secret. Fake caching seems designed to throw looters off track, . But perhaps it’s also a character test for fellow ravens? Or maybe—for the intelligent raven—it’s all just an amusing shell game?

For sources and pictures for this and past stories, go to

For Wild About Utah, I’m Holly Strand.


Images: Courtesy Wikimedia/ Steven Pavlov, Photographer
and Courtesy US FWS, Gary M. Stolz, Photographer
Text: Holly Strand

Sources & Additional Reading:

Balda, R.P. & Kamil, A.C. 1989. A comparative study of cache recovery by three corvid species. Animal Behaviour 37: 486-495.

Boarman, William I. and Bernd Heinrich. 1999. Common Raven (Corvus corax), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: .

Bugnyarf, Thomas and Kurt Kotrschal. 2001. Observational learning and the raiding of food caches in ravens,Corvus corax: is it ‘tactical’ deception? Animal Behavior, Volume 64, Issue 2, August 2002, Pages 185–195.

Heinrich, Bernd and John W. Pepper. 1998. Influence of competitors on caching behaviour in the common raven, Corvus corax . Animal Behaviour. Vol. 56, 1083–1090

Marzluff, John and Tony Angell. 2005. In the Company of Crows and Ravens. Yale University Press.

Tomback, Diana F. 1998. Clark’s Nutcracker (Nucifraga columbiana), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: .

Lewis and Clark’s Taxonomic Legacy

Clark’s Nutcracker
Courtesy US FWS
Dave Menke, Photographer

Lewis’s Woodpecker
Courtesy US FWS
Dave Menke, Photographer

Thomas Jefferson will forever be remembered as our third president and author of the Declaration of Independence. Jefferson oversaw the acquisition of the vast Louisiana Purchase and soon thereafter initiated planning for an expedition that would be named the “Corps of Discovery”. That bold adventure was led by Meriwether Lewis and William Clark. These two frontiersmen are immortalized by the plants and animals that taxonomists named in their honor.

The arduous 3-year expedition route passed far north of what would become Utah, ascending the tributaries of the Missouri River and later following down the Columbia River to the Pacific Ocean. Jefferson, being an avid naturalist, instructed the explorers to observe and make record of the geography, plants and animals that they encountered and to return with those specimens which they could carry. Hopes for discovery of a navigable inland passage to the Pacific were not realized, but in all other ways, the expedition was a singular success.

Lewis and Clark made collections of pressed plants along the way. These eventually went to Frederick Pursh, a German botanist in Philadelphia. One new genus of plant he named Lewisia. These are the bitteroots, one of which is the spectacular state flower of Montana. Another genus new to science he named Clarkia . Many species names of plants immortalize the men too, such as the blue-flowered flax, Linum lewisii, commonly used today for seeding following wildfire.

Bird names honoring the discoveries of Lewis and Clark include Clark’s nutcracker and Lewis’ woodpecker. Clark’s nutcracker is a big black and gray relative of crows. [,] This noisy resident of Utah’s mountains is notable for its habit of caching seeds of pine trees to be remembered and found months later.

The age of the pioneer naturalist in North America closed more than a century ago, but the names of men like Meriwether Lewis and William Clark live on with the plants and animals that bear their names.

This is Linda Kervin for Bridgerland Audubon Society.


Images: Courtesy US FWS
Audio: Courtesy & Copyright,
Text: Jim Cane, Bridgerland Audubon Society

Additional Reading:

The Lewis and Clark Herbarium, Images of the Plants Collected by Meriwether Lewis and William Clark, 1804-1806, Presented by the University of Maryland and The Academy of Natural Sciences in Philadelphia in cooperation with Cornell University,

Evans, Howard Ensign. 1993. Pioneer naturalists: the discovery and naming of North American plants and animals. Henry Holt & Company, New York. Illustrated by Michael G. Kippenhan. ISBN: 0-8050-2337-2,

And for a thorough treatment of Clark’s nutcracker:

All About Birds, The Cornell Lab of Ornithology: