Tuesday, October 14, 2008

Blakeman on Bluejays

The Camman's great White Oak

John Blakeman, the Ohio Red-tailed Hawk expert , has been absent from these pages for many months.I was delighted to receive a note from him shortly after I posted Murray Head's superb photo and enlargement of a Blue Jay with a beak-full of acorns. Blakeman wrote:


The delightful photographs of the blue jay with acorns in its mouth are more than a passing curiosity. These photos graphically record a significant ecological force, something not so often attributed to the feisty little blue jay. The story is this:

Out in the Midwest, on prairies from here in Ohio all the way to Nebraska, the original landscapes had tallgrass prairies, scattered and not so large here in the Buckeye State, but ever more massive to the west.

Bordering virtually all Midwestern prairies were oaks, both in dense, closed-canopy oak forests, and also in scattered, wider occurrences in the numerous oak savannas out on the prairies themselves. Just as pines and spruces dominate the evergreen vegetation of the Rockies and other montane communities, oaks dominated the borders of Midwestern prairies.

Even today, when traveling through former prairie areas of Ohio, Illinois, Wisconsin, and other Midwestern states, a few scattered, lone oaks stand majestically out in the open landscape. A few of these patriarchs are two or three centuries old, standing monumentally above the surrounding pastures, row-crop fields, or along rural highways. These trees are ancient and majestic.

But inquiring minds should wonder about how these large, isolated oaks ever got “planted” so far out away from a parent tree. Acorns are rather big. Winds don't blow them far from the parent tree. Still, large, isolated and distance oaks are found all over the prairie landscape. Just how did those acorns get so far out into the original prairie?

Yes, blue jays – just as shown in the photos. For reasons we don't fully understand, blue jays have a propensity for picking up acorns and flying away with them to distant meadow areas. They drop them in new areas, perhaps as a future source of food. Many, of course, are never found and they germinate into oak seedlings.

Without the blue jay and its strange propensity to pick up and distribute acorns into new, open areas, the great American prairie would be absent its iconic oaks. Squirrels carry acorns, but never far. Blue jays are the most significant agent for oak dispersal.

Just down the road from me is the Cammann’s great white oak. It’s between three and four hundred years old. I'm certain it started as an acorn dropped by a blue jay those many years ago, a time when this area was a tallgrass prairie with savanna oaks.

Blue jays, thanks. From little acorns grow giant oaks -- on the prairie with the assistance of this feisty little corvid.

–John A. Blakeman