Of Bears and Oaks: Finding black bears this Fall

What is it about bears that speak to us in such a profound way? Take a sampling from wildlife photographers across the northern hemisphere and ask them what their favorite subjects are. Chances are, you will find most say either bears or owls.

But why?

Far from being a snarling bear, this is a large boar who was simply vacuuming up acorns off the forest floor. Because of the way in which black bears go about eating acorns, they are very particular about which species of oak trees they will feed from. Know this, and you will find black bears this Fall. 

Why do we revere these species to the degree that we do?

Honestly, this is nothing new. Our ancestors did the same. From nature-based communities such as the Algonquians on one side of the Atlantic to the Celts on the other, bears and our reverence for them, is a cross-cultural phenomenon.

I’m no different.

Like all aspects of my work with wildlife, it all begins with an understanding of the animal’s biography. As food and sex drive all life on Earth, knowing the food sources of your subject is sort of wildlife photography 101.

As of late, I have spent a lot of time writing about bears across the intermountain west on up through Alaska. But Ursus americanus, America’s bear, lives in every corner of the continent where forest can be found. And far more people travel to locations in the eastern deciduous forests in hopes of seeing and photographing black bears than all of the west combined.

So, for those of you east of the Mississippi: this one’s for you.  

For the black bear of the eastern forests, the acorn is the giver of life. Much ink has been spilt over the unique associations between these bears and those trees of the genus Quercus, but bears are not alone here. Some 180 different species depend on oak trees each year for their survival. In the deciduous forests, the oak is unquestionably the Tree of Life.

Each fall, black bears undergo unique changes in response to the acorn crop. Normally, black bears are what we call crepuscular in nature. This means that they limit their activity to the edges of light – dawn and dusk / early morning and late afternoon for the most part. But when the acorns begin to ripen, they become active 24/7.

Sure, they nap. But they can be found foraging throughout the day and will range far beyond their normal territories in what biologists refer to as the “fall shuffle,” moving from one crop of acorns to the next.

This is important to understand for wildlife photographers interested in photographing black bears. Acorns change the behavior of the species. This food source gets them up and moving about. And it increases your likelihood of finding bears when there is enough light to manage a decent exposure.

But not all acorns are created equally in the world of black bears.

You see, oak trees have a natural defense against predation. All plants do. And we call them alkaloids.

Alkaloids are the chemical weapons of the botanical world. For us humans, these alkaloids are what create drugs, poisons, and medicines. Caffeine is a good example this. It’s technically a neurotoxin that will drop insects dead when they consume it. But for you and me, it clears away the fog in the morning and gets us going.

For oaks trees, the chemical weapon of choice comes in the form of tannins. This is the same stuff that turns your tea brown, and the sluggish waters of a swamp black. Tannins, or tannic acid, is extremely difficult for animals to digest and can even kill some animals if they ingest enough of it.

While there are many different species of white oaks, the key characteristic for identifying these trees is the lobes on the leaves. In this photo above, you can see the soft rounded corners. Red oaks, on the other hand, have sharper points (bristles) instead of lobes. Understanding the difference between red and white oaks can mean the difference between filling memory cards full of photographs of black bears this fall or simply going for a walk in the woods. 

While there’s around ninety different species of oaks in North America, we basically have three “types”: live, red, and white.

Live oaks are confined to the coastal plain of the southeast, the Gulf Coast, and California. These have the least amount of tannic acid of any oak and are therefore the most highly sought after by wildlife. But the live oak’s range is limited and, in most places, where the tree can be found, you can no longer find black bears.

This means that the bulk of acorns on the ground come from either red or white oaks.

If you were to ask a plant nerd how to identify a red versus a white oak, they may tell you that to properly differentiate between reds and white is to inspect the inner surface of the acorn cap. A red oak has tiny hairlike structures whereas white oaks don’t’. This overcomplicates things for us, however. So, let’s make this easier:

Red oak leaves come to distinct points whereas white oak leaves are lobed.

Understanding this distinction is important if you have any interest in photographing black bears.  

Though red oak acorns have significantly higher fat content, they also have significantly higher levels of tannic acids. For those species that gnaw their way through an acorn, like a squirrel, this is the preferred food source because the fat and tannins are found in separate places within the acorn. If you chew up and spit out the tannin rich outer layer, you are rewarded with the best nut in town.

Bears don’t gnaw on an acorn, selectively eating one part and ignoring others, however. Instead, they sort of vacuum them up off the forest floor and pulverize them with their teeth - swallowing whole. It’s this difference in how they eat acorns that determine their preference for white oaks over reds. Since black bears basically gorge themselves on as many acorns as possible, the amount of tannic acid in the acorn is important.

While white oaks may have less fat than red oak acorns, they have significantly less tannic acid as well. Animals have a natural aversion to foods with a lot of tannins. While too much of this stuff can kill, it also hinders digestion and the absorption of nutrients in much smaller quantities. As such, white oaks are the perfect compromise. Even though red oaks are more nutritious, white oaks still deliver about the same amount of nutrition as corn does. Now take away all those tannins, and you have yourself one of the most important food sources in the forest for a lot of different animals.

This is why knowing the difference between red and white oaks is important. Just because you find a good crop of acorns on the ground doesn’t mean you will find bears. You need to be able to understand where the white oak stands are, as opposed to the red oak stands, and focus your efforts accordingly.

These are the details that can revolutionize your ability to find and photograph wildlife. Sure, you can travel to a national park and simply drive around until you happen upon an animal or a group of other people photographing. But where’s the fun in that? Understanding the unique story of your subject, such as a black bears preference for white oak acorns, allows you to focus your efforts and increase your success.

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