Sunday, June 10, 2012

Black Bears and Bear corn

Hiking in the Smokies in early June, I came upon a young black bear foraging in the woods. Partially hidden behind a large dead hemlock tree, and with a pair of binoculars in hand, I watched the bear consume the fruits and shoots on multiple clumps of bear corn, a process that went on for nearly an hour (and delayed quite a few hikers, too). A subsequent look at the literature revealed that the flowering and fruiting structures of bear corn are an important part of the diet of black bears. White-tailed deer as well as smaller mammals such as squirrels, chipmunks, and mice also feed on the flowers and fruits. In addition to obtaining nutrients, it's thought that bears seek out squawroot to stimulate bowel activity, particularly after emerging from hibernation.

What about the plant? Does it benefit from this interaction with mammals? As you may have guessed, the answer is yes, as viable seeds of bear corn have been recovered in the scat of black bears and white-tailed deer. While the tiny seeds of bear corn can be transported short distances by rainwater flowing across the soil surface, black bears and other mammals feeding on ripe fruits play an important role in dispersing the seeds over a larger area. This increases the chance that at least some seeds will be deposited in close proximity to the roots of a suitable host plant, required for successful establishment as bear corn is an obligate root parasite (mainly on oaks). 

There's a human connection to bear corn as well in that Native Americans of eastern North America used it as a medicinal plant.