Of Acorns and Oaks and Ants
Beautiful and sacred and a darned nice home for some
Over the past few weeks, I have been enjoying the acorns along Ravenna Boulevard. I first noticed them crunching under my tires as I rode along the road. Up to an inch long, the acorns were also abundant on the grass under the trees. All lacked their handsome, little beret-like cupule but were still quite wonderful to behold. And, gather; several times in past years, I have seen people harvesting acorns along the road. Loaded with carbs, proteins and fat, acorns are a splendid food source not just for people but for animals ranging from mice to black bears. In Lynda Mapes’ wonderful Witness Tree, she writes that the scientific name for oaks Quercus could be derived from the Greek “choiros,” or pig, an animal well-known for relishing acorns.
Taking their relationship further, some animals convert the acorn’s hard shell into a home. When I lived in Boston, one of my favorite “discoveries” was a colony of wee ants inhabiting an acorn. Unlike many ants, which build their own nest, this species (Leptothorax longispinosus) is an opportunist moving into a prefab-site such as an acorn, rolled-up leaf or grass stem. In an acorn, the ants usually are the second shell-exploiters, following beetle larvae or millipedes that bored a hole through the shell and ate the energy-rich acorn. After their fellow acornophiles exit, ants move in, clean out the debris (usually frass), and establish a home.
Sadly, I don’t know of any acorn-dwelling ants in Washington, most likely because the state has only one native oak, the Garry or Oregon white oak. David Douglas bestowed the scientific name, Quercus garryana, to honor Nicholas Garry, secretary and later deputy governor of the Hudson Bay Company. More common south of Tacoma, particularly on the prairies around Nisqually and Ft. Lewis, Garry oaks prefer sunny, open, well-drained sites. In Seattle one can find large Garry oaks at Seward Park, Oak Manor and Martha Washington Park. (Two streets, Oaklawn Place and Oakhurst (hurst is an ancient word meaning grove of trees ) Street, indicate that oaks were common or unusual enough to merit street name recognition near Seward.)
Edward Curtis wrote in The North American Indians that Indigenous people from around Puget Sound would canoe down to the Nisqually plains and collect hundreds of bushels of acorns, which they roasted, ate raw and used for bread making. Harvesting these delicacies involved active management of the land. Using fire, they killed Douglas fir seedlings, which grow faster, eventually shade out oaks and can take over an oak prairie, if not prevented so by fire, a process now occurring around Ft. Lewis and on the Mima Mounds, south of Olympia.
Piqued by seeing the acorns along Ravenna, I have continued to seek out oaks and acorns around Seattle; they are everywhere. It’s not clear why the Ravenna oaks (which appear to be English oaks) are having a mast, or high quality production, year, but apparently they are special. I have found only one other location with acorns, despite there being more than 44 species and cultivars in the city, according to the amazing Arthur Lee Jacobson. (Worldwide there are more than 500 species; many are notorious for their promiscuous interbreeding!) The acorn bearing oaks grow near what used to be Oak Hill School, in northeast Seattle.
As Lynda writes in her book, oaks have long been intertwined with people. The Druids worshipped and whooped under oaks; the Vikings sacked and terrified in their ships of oak; and King Arthur and his pals discussed the great ideas of the day around their circular table of oak. And, of course, they are beautiful and inspiring, especially in fall as their leaves turn russet and red. The PNW is justifiably famous for our conifers but we also have lovely deciduous trees, many, such as oak, which are showcasing their fall colors. Such trees are one advantage of living in a city with its diverse population of trees from around the world.
~By David B. Williams, reprinted with permission from author.
Editor’s note: David B. Williams is the author of many books focusing on our region including Seattle Walks and Homewaters: A Human and Natural History of Puget Sound. You can sign up for his newsletter “Street Smart Naturalist: Notes on People, Place, and the PNW” at firstname.lastname@example.org.