Have you ever noticed that some years are better than others for acorns? Sometimes it seems like millions can be dropping from every oak tree.
Acorns are, of course, the seeds of oak trees. From the tiny acorn springs forth the mighty oak. They are produced by the tree’s tiny flowers, which are wind-pollinated in spring. All oak trees produce separate male and female flowers on the same tree – a reproductive condition called monoecious. It is the female flower that will result in an acorn after it has been pollinated.
The caps of the acorn are a collection of overlapping modified leaves that protected the female flower before it blossomed. The acorn itself is the female flower’s ovary that has grown and hardened with a protective shell around a single seed within.
The meat within the acorn is what nourishes the germinating seed until it can produce its first leaves. The acorn meat is kind of like the yolk in a bird’s egg, which nourishes the developing chick within.
As you might imagine, acorns, just like eggs, are a very desirable food source for a lot of wildlife. Many birds, such as Wild Turkeys, Ruffed Grouse and Wood Ducks, feed heavily on acorns at this time of year. Each of these birds has a strong “upper stomach,” called a gizzard, that enables them to swallow an acorn whole and grind it into digestible food.
Other birds, such as Blue Jays and some woodpeckers, will hammer an acorn shell open with their bills before eating the meat inside. Animals such as Eastern Chipmunks and Red Squirrels gather hundreds of acorns for winter storage. They simply and easily peel the shell open with their sharp incisor teeth to eat the seed within. Black Bears, Northern Raccoons and White-tailed Deer also eat acorns each fall. They use their strong molar teeth to grind the acorns before swallowing.
While many animals eat acorns, it’s the Eastern Gray Squirrel that actually helps the oak tree. If you have ever watched a gray squirrel, you will notice how they find a single acorn and carry it off to bury it in a shallow hole, presumably for later consumption. Since it’s impossible for the squirrels to remember all of their hidden treasures, the forgotten acorns (which have been “planted” at the ideal depth for germination) foster the next generation of oak trees.
All of our oak trees can be broken into two categories or groups. The first is the white oak group (or sometimes called black oak). These trees have flowers that produce acorns every year. Most years they produce a small to moderate amount of acorns per tree. However, once every 3-5 years and sometimes every other year, these trees produce huge crops of acorns. This is called a “mass crop” of acorns.
The second category is the red oak group. This group of trees produces acorns every other year. Red oak flowers are pollinated in the spring, but the acorns are not ripe until a year from the following autumn.
So how do you tell if your oak tree is in the white or red oak group? It’s simple. Oaks that have leaves with rounded lobes are in the white oak group. Oaks with leaves that have sharp points are in the red oak group.