Two Months After the Mast—Part 2

I looked last time at the need for people to predict the coming winter’s severity by consulting folk omens. It was first the wooly bear caterpillar. Now the masting of acorns…

Another favorite winter prophecy is the size of the fall crop of acorns. This story goes that if a hard winter is coming, Mother Nature is planning ahead for the protection of her charges. She’s directed the oak trees to grow an extra large batch of acorns so the squirrels, mice, deer, and turkeys will have enough to eat, to get through the coming severe winter. It’s nice to think that nature does such a kindhearted job of planning, so all her critters are well cared for.

Squirrels, the belief goes, return the favor by helping to grow more oak trees, when they bury acorns and then forget where some of their stash is. Well, there’s a little truth to that, but your average squirrel has a better memory than this gives it credit for. Moreover it kills far more acorns than it plants—either by eating them or simply biting into them and destroying the seed. The squirrel is more a foe of the oak, than a friend. In turn the oak would consider squirrels to be a menace—not a friend to feed.

So what’s going on? A heavy acorn crop is an example of the genius of Mother Nature, but not as a prognosticator of winter. Instead, it’s her way of ensuring the survival of the oak forest. A bumper harvest of acorns is called “masting.” If oak trees were to put out the same number of acorns every year, the squirrel population would stabilize at a level that would see most all acorns consumed. If there were more squirrels than that, some of them might starve; fewer in number and they’d quickly multiply, with all those extra nuts available.

The oak survives by keeping squirrels (and other acorn-eating critters) off balance. The trees put out a conventional (even predictable) supply of acorns for several years, fooling the eaters into thinking that it’s all they’re gonna get. Then, when the animals are looking the other way, the oaks surprise them by masting—producing a copious crop of acorns and carpeting the forest floor with them. The animals may gorge themselves, but cannot eat them all. Some acorns will survive and sprout new oaks. Since oaks live for so long, they need to mast only every few years.

One marvelous feature of the masting process is that most all of the oak trees in a locale will mast the same fall. You can imagine what would happen if the trees didn’t coordinate their crop: randomly scattered oaks would mast when their cohorts would be taking it easy. Such randomness would negate the masting effect. But oak trees are in unison when they mast. How do they do this? We don’t know for sure, but plant research is showing us that trees communicate chemically with each other. They do this in defense of insects—to alert their buddies about invasions. Might they use the same technique to coordinate their masting?

I sure don’t want to take the fun out of checking out wooly bears and monitoring the abundance of acorn crops. Being attentive to nature is a wonderful thing. I love to examine those cute caterpillars, as well as marvel at the abundance and many shapes of acorns during a mast. We might be careful, however, about projecting our idiosyncrasies and hankerings onto Mother Nature. She’s beautiful enough in her own right, that we don’t have to dress her up in anthropomorphic clothing.