Nature Notes: Hand in Hand

Fruiting trees, the oaks among them, evolved hand in hand with the birds and mammals

    Acorns falling on the roof, isn’t that a phrase from a popular song? Acorns have been falling on my roof since the last week in September. Most of them get caught in the gutter and are easy picking for jays, squirrels, chipmunks, white-footed mice, and raccoons. Long Island’s forests are derived primarily from the eastern deciduous biome centered in the Appalachians. While key Appalachian states like North Carolina, Tennessee, West Virginia, and Pennsylvania have more oak species than any other states or other countries, Long Island has its share.

    Several oaks are in the white oak group, including the white, swamp white, chestnut, post, and dwarf chestnut oaks. Other species are in the black oak group, the black, red, scarlet, bear, black jack, and pin. Lately the Southern red oak has crept into Montauk, almost unnoticed. Native pin oaks are quite scarce. The other day I happened upon a group of five on the north side of Swamp Road in East Hampton’s Northwest Woods while looking for a stand of persimmons. The only other pin oaks I have encountered on eastern Long Island were in the Village of North Haven.

    Oaks are noted for their sturdiness and are prized woods for furniture making and flooring. After the scourge of gypsy moths followed a scourge of canker worm moths in the early 2000s, an army of dead leafless oaks stood for years on the South Fork before crumbling and falling to the ground. A few are still standing, but most are long gone. Just as the acorns of white oaks were prized over those of black oaks for making various foodstuffs used by the local Native Americans, the leaves of white oaks were favored by the gypsy moth larvae and cankerworms over those from the black oak group. Consequently, more than 90 percent of the killed oaks were white oaks, several of them more than 100 years old and two to three feet in diameter. It’s a pity that very few of them were salvaged for lumber before succumbing.

    Fruiting trees, the oaks among them, evolved hand in hand with the birds and mammals, beginning more than 100 million years ago in the last years of the dinosaur dynasty. Birds and mammals eat the fruit, defecate the hard pits, the pits fall on the ground, and another generation of trees is started to feed another generation of birds and mammals well into the future. Sweet fruit — blueberries, huckleberries, black cherries, beach plums and the like — is very rarely cached, as it ferments and goes bad if left for more than a few days in the open. Its “stones” are deposited a few days after being eaten, mostly in the summertime.

    Nuts, say those from hickories, walnuts, beech, and oaks, don’t ripen until the end of summer and are enveloped in a tough rind so that they last a long time on the ground without going bad. The rind of the acorn is its cup, thus only a half a rind. You see squirrels running across the road with nuts as big as walnuts and hickory nuts in their mouths, many of which will be stored for winter eating.

    Acorns on the other hand, are frequently eaten on the spot, especially by chipmunks and squirrels, but many are hidden away, as well, oftentimes in such quantities to last all the way to spring. If you take a few minutes to observe blue jays and squirrels picking up acorns and hiding them here and there, you might also observe an interesting interaction between the two. I watched the other day as a blue jay picked up an acorn from my backyard and placed it in one of the 50 or so plant pots, some with plants, some without, residing there. Then it plucked the acorn back out and went to another spot.

    A half hour later a squirrel came along shaking its tail vigorously, went to the pot where the blue jay had been, but didn’t come up with an acorn. Then it proceeded to go from pot to pot, apparently, searching for the edible loot, but came up empty. Or it could have been that the squirrel was also hiding its acorns in the flowerpots. When you think about it, the acorn stored in a flowerpot is more easily found come January than one stored in the ground.

    But it becomes a problem when both jays and squirrels are using the same pots to store their acorns. One or the other may lose out.

    Walnuts, hickory nuts, and, to a degree, acorns are round. They roll. If dropped from trees on a hillside, they will tend to move downhill over time, either to be eaten or end up starting new trees. In the spring, three years ago after a big acorn crop in Noyac, I noticed several little black and scarlet oak seedlings germinating in the earthen shoulder of Noyac Road in front of my house. The road slopes down as it passes my house, the acorns had apparently rolled down from trees up the road a bit, then were covered by snow from the snowplows, and after the snow melted in March began to sprout.

    Recently, I learned that acorns in the white oak group begin germinating in the fall shortly after dropping to the ground, while those in the black oak group don’t germinate until the following spring. This could be a survival mechanism based on taste. Since the white oak acorns are preferred, if they didn’t germinate until spring, they would be picked before the others. If they germinate right away, there’s a good chance that they will have a root in the ground and an opening shell and will already have become unpalatable.

    But the black oak-group acorns have a different adaptation to survive. They don’t have a good acorn year every year. When they do have a good year and a multitude are cached in soil to be eaten later, many go uneaten, and germinate come spring. In other words, the blue jays and squirrels have been planting them unintentionally, rather than merely hiding them. Or is it that jays and squirrels have evolved side by side with oaks for such a long time that they are not only concerned about getting through another winter, but also looking out for future generations and their survival and procreation? Plant now, eat later, much later.

    The different oak species are also competing for top billing. The whites are trying to get ahead of the black by germinating earlier. But even among the whites there is competition. The chestnut oak, for example, takes only a year to produce a ripe acorn, while the others take two years. This is a big year for chestnut oak acorns. The Trout Pond preserve and the rest of Noyac are full of them. Theoretically, the chestnut oaks could take over the farm, as they are twice as productive as the others, but this is not the case. They are just another oak as far as oaks go, certainly not the top-dog oak species by a long shot.