A barred owl rests in an oak
A thousand stories come together as you observe all of the life associated with oak trees
One of my favorite things to do is to take a lightweight three- legged folding stool out on hikes and sit down for a while in areas that show a promise of something good to come if I can simply wait a bit. It is always a surprise to discover all the activity going on that I would have missed because of a failure to employ the railroad method of outdoor walking: “ stop, look and listen “.
Doe sleeping under an oak in the winter
Oaks provide a great opportunity to observe all kinds of life, as they are a major food source for many caterpillars, cicadas, katydids and other species of insects.. Holes from feeding insects, leaf shelters containing caterpillars and leaf or twig galls are just a few things you may notice. But a closer look will prove that is just the tip of the iceberg.
Tiny creatures seen crawling along twigs and leaf undersides may be the nymphs of some sort of tree hopper insect. Caterpillars might dangle down on silken threads, spiders may have woven webs among the branches and mushrooms arise from duff underneath the trees. Oaks provide nesting sites for many birds and animals, and food in the form of leaves, twigs and acorns.
Spider silk dangling from an oak on an October morning
Early in the spring when oaks are just beginning to show swollen buds, catbirds normally are back. And as leaves begin to unfurl, look and listen for scarlet tanagers and Baltimore orioles in the top of the canopy of mature oaks. There must be caterpillars there because you will see them poking around and under the newly opened leaves. Male red- bellied woodpeckers advertise the fact that they have constructed a fine nesting cavity suitable for any females in the area. The males can be hard to spot because they sit inside their hole and poke only their head out and sing sporadically all day. Because of past storms, many oaks have dead vertical limbs that are just what red- bellies like for drumming and excavating.
Male red bellied woodpecker sings from inside his newly created nesting hole
Oaks have the distinction of being the host for many gall insects. While most are not a threat to the health of the tree, they can occur in large numbers. One of the most common galls familiar to many people are those formed by the oak apple gall wasp. These are large and are a smooth with a limey green color. Neatly tucked inside is the larva of the wasp, safe and sound from predators. A gall of the wool sower wasp is associated with white oaks and it looks somewhat like a toasted marshmallow.
Wool sower wasp gall on white oak
Oaks are also the host plant for over 500 species of moth caterpillars, which makes them the champ when it comes to supplying bird food in Connecticut. From spring until fall, check out oak leaves for any caterpillars that may be there. Late in the summer, walking sticks might also be found on oaks.
Afflicted dagger caterpillar on an oak
Yellow-based tussock moth caterpillar on white oak
Butterflies such as the spring-flying Juvenal’s duskywing, banded hairstreak, striped hairstreak and red-spotted purples also use oaks as host plants for their caterpillars. If these butterflies are seen, check out any nearby oaks for the caterpillars.
Juvenal’s duskywing butterfly uses oaks as a host plant for its caterpillars
Several weevils are associated with oaks, among them the acorn weevil. The female lays an egg inside an acorn by chewing out a hole with its mouth and inserting one egg inside the developing fruit. Look for acorns in the fall that have a small round hole. This is evidence that the larva that was feeding inside has exited by chewing its way out. Sometimes squirrels can be seen turning acorns around in their paws as they look for these holes, or feel the weight of the acorn. They will not waste valuable time opening an acorn that will not supply a sufficient supply of food.
Female acorn weevil on red oak
New York weevil on oak
A few years ago, there were lacewing eggs everywhere on the undersides of all kinds of oaks. The next year- hardly any on oak, but there were a lot on cherries. In late summer. Lacewing larvae move about on the top of oak leaves with old molted exoskeletons and other debris piled on their backs. They look like little mobile fuzz balls.
Lacewing eggs under an oak leaf
Deer and turkeys rely on acorns for food during the fall and winter. Sometimes you can see the places under oaks where deer have dug through the snow looking for acorns. Gray, red or flying squirrels will also eat acorns and may also nest in the trees as well. Once year a pair of young flying squirrels were out during the day because their nesting hole was damaged by a fallen branch.
Young flying squirrel
The next time you see an oak, imagine all that may be happening on, around and under that tree. Look a little closer and see what you can find. And enjoy its shade at the same time.
Pamm Cooper
You have to look close to see the gray tree frog on this tree trunk
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