Ecoregions and Robert Bailey of the U.S. Forest Service
Every now and then I leaf through past issues of the Wild Ones Journal (which you can do easily if you put all your past issues in 3-ring binders on publication hangers, available from Donna VanBeucken), and revisit an issue that impresses the socks off me. The May/June issue of 2002 is one such. In fact I would call it a milestone issue. On three pages a small cadre of members/volunteer writers restated the Wild Ones mission statement and brought us up to date on new ideas. They very succinctly introduced us to ideas of ecoregions and local ecotypes. Portia, Mariette, Pat, Lorraine and Christine, thanks again for a complicated task well done!
It is up to us, the readers, to educate ourselves more deeply, to take ownership of the ideas of ecoregions and ecotypes.
Which came first, the blue jay or the oak…
In a hollow by my pond not far from the house is a grouping of three bur oaks. They are all of an age and three or four feet apart. I have wondered how they came to grow there, so close together, as if all planted at the same time, at the edge of a deep woods. They aren’t in a straight line or equidistant so they don’t seem to have been tended by a human hand.
I believe I found my answer in an essay in “Living Bird,” published by the Cornell Lab of Ornithology.
It seems that in the fall blue jays engage in an instinctive and secretive burying behavior. They carry four and five acorns at a time in their mouths to spots at the edge of the forest and bury them as part of their winter cache. If the jay happens not to find all his cache before spring, the acorns are at just the right depth to sprout and survive—sheltered, but not as deeply buried as by a squirrel.
Radio tracking work has found that an individual jay may cache as many as 5000 acorns in a single season, carrying them a distance of more than a mile or sometimes flying from one tree to the next, in spurts of less than 100 yards.
To understand the physiological challenge faced by the jay, you might pop three or five acorns inside your mouth, hold another in your teeth, and run around the block. If the warm-up lap doesn’t get your heart racing, spit out the acorns and replace them with coconuts for a more proportionate sense of the jay’s burden.
In Oecologia, Natural History and Journal of Biogeography, W.C. Johnson of South Dakota State University has argued “air transport by jays must have been a primary reason for the swift range extensions of oaks and beeches northward up the continent as the ice retreated from North America following the most recent Ice Age. Because their seeds were so often carried to the leading edges of the forest – where jays prefer to cache – oaks and beeches moved north much faster than they could possibly have done without avian assistance”.
Other biologists have noted that oaks reach their greatest diversity where jays are also most represented and are absent from areas of the globe that jays don’t inhabit.