I have enjoyed wandering through Story County’s wilder areas for well more than 60 years. I love to wander in places like McFarland Park, the Skunk River Greenbelt and Robison Park. Even though I’m sometimes lulled into thinking I’ve seen pretty much everything those areas have to offer, there’s still a good chance that I’m going to stumble onto something new and interesting. Nature isn’t static. Things change over time. Sometimes it’s human management practices that bring change about. Sometimes it’s the slow and steady change of living, growing things. At other times, the changes can be profound and as quick as a violent storm passing through.


Recent hours spent in the woods here and up at my wife’s home farm along the Cedar River revealed that 2018 is turning out to be a good “mast” year. Mast, to a forester, isn’t a pole that sticks up from the deck of a boat. It’s the fruit of forest trees; particularly nuts. There’s also “soft mast” in the form of berries. Some walnut trees are really loaded with nuts, and some oaks are dropping loads of acorns. The squirrels are burying shagbark hickory nuts all over my yard, and often carry them nearly 150 feet from the nearest hickory tree before burying another one. The ones that they don’t dig up and eat over the winter will be sprouting all over my yard next summer.


Mast, both hard and soft, is crucial for forest wildlife. Nuts maintain their nutritional value all winter, as do dried berries that remain above the snow. Nuts are high in vegetable fats and proteins that many kinds of birds and animals need to fatten up before harsh winter weather sets in. All mast is not created equal, though. Walnuts are prime food for squirrels with their strong jaws and sharp teeth, but are too hard to chew into for smaller animals and too large to swallow whole. Hickory nuts and hazelnuts are also hard, but are small enough for even little animals to handle. Bitternut hickory nuts, on the other hand, are ignored for the reason their name implies. Acorns are consumed by birds and animals alike. Rodents, even little ones, can easily chew through their soft shells to get at the nutritious nut meat. Many rodents store piles of them away in hollow trees and stumps. Birds, like wood ducks and wild turkeys, swallow them whole and let their powerful gizzards grind them into usable food. Woodpeckers wedge them into tree bark where they can easily find and feed on them later. Deer gorge on them in the fall and prefer them even over corn. The most highly preferred acorns are from the white oak family. Acorns from the red oak family are loaded with tannin, are very bitter and are largely ignored at least early in the fall when more desirable foods can be found. Birds, without many taste buds, are more likely to use them now. They’ll be consumed later by all kinds of creatures when times are tougher. Some of the bitterness may be leached out by fall rains, but even bitter food is better than no food.


Back to my wanderings, though. I recently stumbled on a rare find in an area where I’ve probably walked a hundred times over the years. It was a mature, nut-bearing butternut tree! I’d have missed it again if I hadn’t seen the nuts. Dozens of the tasty football-shaped nuts littered the ground. The tree is very similar to a walnut, and I suppose I never gave it a second look for that reason. Butternuts were very common in bottom-land timber 50 years ago, but they have nearly been wiped out by butternut blight, a fungal disease. It’s been years since I Iast found one. The nuts are milder than walnuts in taste and are prime squirrel and human food. Perhaps this was just a good mast year, or perhaps most of the nuts had already been gathered by hungry critters or people when I’ve walked by that area in the past. Regardless of the reason, it was an exciting find. Maybe that tree has a rare gene that makes it more resistant to the blight, like some elms that have survived to maturity in spite of the continuing presence of Dutch elm disease. I hope that’s the case, and that at least a few of the nuts survive the winter to sprout into more butternut trees next year.


Steve Lekwa is a former director of Story County Conservation.