A blue jay enjoys a peanut treat in a Salem driveway (Courtesy/Harry Fuller)
Our species has been using plants and their fruit throughout our existence. First, our ancestors took what they found. Later, some plants were favored and encouraged because they were so tasty or useful. Eventually agriculture evolved and now food production is part of a complex global economy.
Here in the Willamette Valley, Kalapuya once managed the landscape with controlled spot fires to encourage oak and other favored plants. Three of their staple foods were wapato, camas and acorns. People weren’t the only animals using acorns, nor even the most efficient.
Squirrels and jays are perhaps the most devoted users of acorns. In autumn jays cache acorns and other foods that won’t rot, often in the soil or under leaves or grass tufts. For eons, jays have cached acorns and left some to sprout. The world’s oak forests owe much to jays and their acorn planting habits. Apparently jays even prefer the acorns most likely to sprout.
Beyond oaks we often see scattered hazelnut, hawthorn, red-osier dogwood, ash, bigleaf maple, Oregon grape, feral plum, chokecherry, rowan, blackberry, twinberry, spirea and other bird-beloved food sources. A bird will eat the fruit, then excrete the undissolved seed. In my garden, I found a half-dozen small rowan saplings. The nearest tree is 200 yards away, and that fruit does not fly through air like cottonwood tufts. The rowan seed has to be transported by a jay or waxwing or robin. Our garden has countless holly, hazelnut, maple, oak and other saplings as the result of bird activities.
Perhaps Oregon’s greatest avian forester is the Clark’s nutcracker. This montane species is known to bury thousands of pine seeds every autumn. They will carry pine seeds and bury them 20 miles from the tree that produced them. Inevitably some are not eaten and become new trees.
English newspaper The Guardian reported on a recent study in England: “during ‘passive rewilding,’ thrushes spread seeds of bramble, blackthorn and hawthorn, and this scrub then provided natural thorny tree ‘guards’ for oaks that grew from acorns buried in the ground by jays.” No expensive equipment, no chemicals, no labor, let the birds build the forest. The first generation of thicket kept the deer from eating the small trees until they over-topped the shrubs. Then the trees formed a canopy and the surviving shrubs became the undergrowth.
Here in Oregon, jays and their cousins are not the only seed cachers. In season chickadees and nuthatches hide hundreds of seeds each day, some of which will sprout next spring.
Harry Fuller is an Oregon birder and natural history author of "Freeway Birding." He is a member of the Salem Audubon Society. Contact him at [email protected] or http://www.towhee.net/. His "Some Fascinating Things About Birds" column will be appearing regularly in Salem Reporter.
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