A flutter of striking black, white, and grey outside the window caught my attention, and as I walked closer I saw a dozen large-bodied, sharp-beaked birds hopping around on the treed hillside. The Clark’s Nutcrackers are here again!
Are they finding insects or pine nuts, or perhaps uncovering food they cached last fall? I can’t imagine them all caching in this one area—although we did have an unusually large population of the birds this year. Could this be due to the mild, snow-free, late fall and early winter.
These well-dressed foresters in their tuxedo-like plumage make their home in pine forests from 3,000 to 13,000 feet in elevation, especially those containing the whitebark pine, their favorite seed, of which we are lucky enough to have a fair number around our property. Making a large bowl-shaped nest of twigs, bark, moss and animal hair in the branches of the pines, these monogamous birds lay between two and four eggs and the parents take turns incubating them.
Clark’s Nutcrackers have a sublingual pouch located under and at the back of their tongue that can hold 50 to 150 seeds. They create caches of up to 15 seeds, though it’s usually just three or four, and they can cache up to 98,000 seeds per season! They store many more than they actually need in anticipation of a sometimes-low availability of alternate foods, and the theft of seeds by mice, chipmunks, squirrels, and a variety of other birds. Clark’s Nutcrackers also have an extremely remarkable long-term spatial memory, able to find their caches with amazing accuracy up to nine months later—even under three feet of snow—by using triangulation, a form of surveying. The seeds that they miss can germinate under the right conditions, so the nutcrackers actually perpetuate their own habitat! This could explain why the young follow their parents around for so many months—possibly learning the complex behavior of caching and then locating the seeds.
Clark’s Nutcrackers are the primary seed disperser for the whitebark pine, whose nuts are the birds’ favorite food. This mutualism makes these members of the Corvidae family a very welcome omnivore in conifer forests. Unfortunately this particular pine is declining due to the long-term effects of fire suppression, an introduced fungal disease called white pine blister rust, and most recently from the aggressive outbreaks of the mountain pine beetle. In order for the Clark's Nutcracker to remain in the forests, the whitebark pines need to continue to grow and be healthy. Should the trees decline to the point of extinction, these birds would lose an important source of food, and then may no longer be found in areas like Yellowstone and Glacier National Parks where the seeds are currently their number one food.
I enjoy watching the acrobatic antics of the Clark’s Nutcracker in obtaining pine seeds. These very agile birds hold pinecones in one or both feet, hacking them open with their strong bills. They also break apart rotten logs looking for beetle grubs, flip dung piles over in search of insects, and eat carrion, berries, other fruits, nestlings, and eggs, as well as peanuts and suet.
As a child I first knew the birds by their apt nickname, camp robber, but they were originally named in 1805 by Captain William Clark, who discovered them on the Lewis and Clark Expedition. On camping trips with my family, I learned that no food was safe from them! I have very distinct memories of these opportunistic feeders announcing their presence with their raucous khraaah-khraaah and nabbing grapes and apple slices, as well as parts of peanut butter and jelly sandwiches! They’re not flighty birds, and they will return with great audacity for another bite!
These memorable, remarkable birds will be around for my grandchildren and our future generations as long as we assist in keeping the whitebark pine forests healthy. What a feathered treasure for us to pass on!
Today’s Field Note was written in the Field Notes Writing Workshop at the Montana Natural History Center. I’m Sue Standley for Field Notes, brought to you by the Montana Natural History Center, providing natural history education for schools and the public throughout Montana. To find out about upcoming events and programs at the Center, call 327.0405, or visit our website at MontanaNaturalist.org.