Jays, Oaks, and Glaciers

100_29181Sitting alone along the edge of a field underneath a dense cover of leafless hardwood branches I watch for wildlife through my binoculars. Like most days spent in the field more happens in my mind than in the wild landscape before me. Still, I am hopeful for some wildlife activity that will peak my curiosity. Waiting in the wilds is a lonely game. I watch the shadows as they lengthen in the aging day. I watch a few clouds, and wish they would shape into wild images like those you read about in stories. I look at my watch again and again, and wonder how time could move so slowly, and then I look at my watch with a suspicious eye and realize that it isn’t working!

It is one of those days when nothing seems to be moving; there is no wind to move the branches above my head and no birds to flitter about the shrubs in front of me. I am not surprised, most of the time wildlife observing has nothing to do with observing wildlife, but rather observing where your mind travels with only its own impetus. On this day I am wondering how our world recovered so quickly after being entirely decimated by the last glacier period. Twenty thousand years ago or so the advancing glaciers, ice sheets miles thick, absolutely wrecked this part of the planet. All animals, plants, soil land formations, and features were displaced completely by the mountains of advancing ice that dominated the landscape. The more fortunate animals were able to migrate away from the advancing ice sheet, but the animals that were not mobile, or incapable of moving ahead of the glaciers were decimated. All plant communities, being primarily immobile, were decimated. Land forms left by previous glaciers were annihilated. Lakes, ponds, and many river beds were filled, scoured, removed, or otherwise wiped out beyond recognition. There were no survivors. Nothing could withstand the type of slow, methodical punishment that the glaciers handed out.

Eventually, thousands of years later, the glaciers retreated slowly. The world they left behind was a moonscape; miles and miles of bedrock and naked earth with no signs of life anywhere. Barren does not even begin to describe the landscape left behind the retreating glaciers.

While I am lost in these thoughts a blue jay lands about 100 feet in front of me. He is holding an acorn in his beak and scratches in the soil puts the acorn down and scratches soil over this oak fruit and flies away. About ten minutes later he returns and does the same thing all aver again. He does this over and over again. Given the time he is gone I understand that the Jay must be transporting the acorns some distance, likely to a spot near his nest. Blue Jays have had a symbiotic relationship with the oak family for thousands of years. The blue jay uses the acorn as a main food source. In turn he plants the acorns up to a mile away from the parent tree usually near its nest, spreading the genetics of that particular tree and expanding the oak forest. A blue jay may move 3000 to 5000 acorns in a given year, only about one fifth to one third of those acorns will be recovered as food. Some of the remaining acorns will be foraged by turkeys, deer, squirrels, chipmunks, and other wild animals, but many will sprout and with a great deal of time grow into oak trees. Not all jays take part in this behavior, some of them migrate south for an easier winter life style.

Immediately after that thought the proverbial light bulb went off in my mind! Eureka, another piece of the puzzle! Is it possible blue jays had a hand in the recovery of the oak forest after being decimated by the glaciers?

Beyond the terminal moraines of where the glaciers stopped there remained unharmed plant communities, wild animals, some of which migrated ahead of the advancing glaciers, and untouched landforms. Some of the higher elevations held some of the same plant species that inhabit more northern latitudes, just like they do today. For instance although the Appalachian Mountains in North Carolina are 800 miles south of the Green Mountains in Vermont they hold some of the same plant communities. The tall Appalachians make up in altitude what they lack in latitude and may have a similar climate to the foothill regions of the north. Although some of the plants may differ, particularly the ground cover plants, many plants may be the same in these two regions due to the altitude difference.

It could be that some of those Jays trying to stay ahead of the glaciers as they advanced in a southward direction settled in high southern altitude areas that still contained some oaks. As the glaciers retreated the resurging plant communities slowly followed the path of the retreating glaciers. First the wind born seeds of herbaceous plants and grasses, then the shrub community, some of which can be spread by root rhizomes, and others by which can be spread far and wide by animal foraging. The trees go last. First the trees that have light seeds, like maples and ash, can repropagate by stout winds dispersing the seeds far and wide. Others, like the black cherry utilize a small hard seed consumed by mammals and birds, and redistributed in scat. But the trees with heavy seeds like the oak seemingly have a problem. Squirrels and chipmunks typically only move them a few hundred feet at a time. Mammals that consume the acorns digest too muck of the seed for it to remain viable.

Could it be that Blue Jay, the pesky little boss of the forest, may have contributed heavily to the replacement of the oak in the northern deciduous forest? Although unintended, the blue jay may be responsible for the fast return of the oak to northern climates and the salvation of many of the forest inhabitants. This bird has special adaptations like a beak that can crush the tough and resilient acorn husk and a throat that expands so that it can carry an acorn while the Jay is in flight. The oak is, along with the beech nut, the premier hard mast (nuts, seeds,and acorns) forage crop of the modern deciduous forest. Before the American chestnut suddenly perished in the early part of the 20th century it was the king of hard mast.

Millions of pounds of forage were produced annually. Its sudden failure created a large gap with respect to wildlife forage. Primarily the oak and it’s seed, the acorn, had to fill this gap.

A strong cool wind from the northwest shakes my thoughts loose and returns me to my surroundings. The day is now long in the tooth and the shadows have lengthened into dusk. As I stand up and turn myself westward I can see the remaining light of day melting away on the horizon. And just then,as if prompted by the bird gods, a blue jay cries from the branches above, and my day is complete with new possibilities and new revelations.

Originally written in September of 2007

  • http://www.warriorforum.com/blogs/rayray7/8778-history-ways-avoid-nigerian-419-scam.html Nicolas Leonti

    I revelled reading it. I require to read more on this subject…I am admiring the time and effort you put in your blog, because it is apparently one great place where I can find lot of reusable info..

  • http://shoreacres.wordpress.com shoreacres

    What a stimulating and evocative post. I’d forgotten one of the great toys of my childhood – the maple tree’s “helicopter” seeds that we loved to toss into the air. And I’ve learned something about the bluejay that explains a behavior I’ve observed. I feed birds, and often will put out raw shelled peanuts or striped sunflower seeds. When the bluejays come, they’ll collect great numbers of peanuts or seeds before flying off. I’ve assumed they were going back to the nest, but didn’t understand how they could carry such a load. It’s that expandable throat!

    I do love bluejays. They’re raucous, and bold, and more than willing to let you listen in on their conversations. They’d make good bloggers!

  • http://www.wildramblings.com Wild_Bill

    I find it funny how so many people do not care for blue jays.  It is true that they are aggressive and will temporarily chase other birds away, but they are such interesting creatures.  These wonderful birds fill a niche that is important to our temperate ecosystems and I thank them for the role they play.  Thanks for reading.  I really enjoy your thoughtful comments.

  • http://www.wildramblings.com Wild_Bill

    Thank you Nicolas.  I do appreciate that you notice the effort I put into my blog and writing.  I can tell you for sure that is no small effort. 

  • Countrymousestudio

    wonderfully informative, I never knew that.

  • http://www.wildramblings.com Wild_Bill

    Thank you.  I love it, love it, love it when I can give readers new information or an alternative glance at the natural window.  You make my day!

  • Wendysarno

    And as I read your piece, Bill, I have a new sense of the wisdom of our planet, how diverse species serve each other. I have a whole new appreciation of my raucous Blue Jays. As William Bryant Logan says in Oak they “give the oaks legs”. Imagine that going on all around us all the time. Gaia at work.

  • http://www.wildramblings.com Wild_Bill

    Yes, Gaia at work.  The conclusion that I’m always looking for.

  • Barbara

    Great column/blog Bill, with lots to ponder as usual. I hadn’t known that blue jays – the circus barkers of the bird species – “Come one, come all, hear ye, hear ye – bring your nuts and seeds – we’re here!” actually buried their treasures. I thought they hid them in small cavities in rocks or trees. Fascinating what you saw and your deductions about the re-growth of the northern part of the continent following the Ice Age. And doubly interesting for me as I’ve just done some work (as a writer) for the American Chestnut recovery team – learning about mast, nuts and their importance to wildlife was similarly fascinating. 

    As always reading your blog is one of the delights of my week. Thanks for such a thoughtful and stimulating piece Bill.

  • http://www.wildramblings.com Wild_Bill

    You are so welcome.  I’m very interested to know what you found out about the American Chestnut!  Is this something you can share?

  • Barbara

    The information should soon be posted on the Ontario government Ministry of Natural Resources website  Species at risk – I was editing a recovery strategy – and it’s confidential until it’s been published. As soon as I get the go ahead, I’ll send you the information Bill.

  • http://montucky.wordpress.com/ Montucky

    I enjoyed your observations about the Jays, Bill. They belong to the forest and the forest to them. Reminded me of a similar arrangement here between the white pine trees and the Clark’s nutcrackers. I wish we fit into the scheme better than we do.

  • http://www.wildramblings.com Wild_Bill

    Man has certainly spread a lot of plants around as we have migrated around this planet, some with good results and others with terrible results (the death of the American Chestnut comes to mind).  Our problem is that we do things so quickly and without thinking everything through.  Nature needs centuries to adapt to change and we can’t be patient for more than a few seconds.  One of our biggest flaws.

  • http://outwalkingthedog.wordpress.com/ Out Walking the Dog

    Fascinating speculation, Bill.

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