Nature scrapbook: Red oak

If all goes according to schedule, this fall should bring good eating in Ontario’s oak woods. In a fruitful year, the harvest season hosts its best wildlife picnics in acorn-laden groves of red oak trees. Flourishing on rocky ridge tops and sandy hillsides, in scattered pockets as far north as Lake Timiskaming and Sault Ste. Marie (and in a thin band running west from Thunder Bay), the fabled, stout-limbed hardwoods exercise a profound influence on life in the forest that far exceeds their numbers.

Mega meals: A red oak acorn contains a single large seed, high in fat and carbohydrates, which takes two summers to mature. Though bitter, it’s a substantial mouthful for a great many creatures preparing for the coming winter.

Feeding the masses: Squirrels begin harvesting the pointy-capped nuts as early as July, even though they’re still green. Later in the summer, bears climb high into the crowns of oak trees and pull the nut-laden limbs 
in towards them, creating signature “bear nests” of broken branches. Deer, ruffed grouse, wood ducks, foxes, mice, 
and many other birds and critters join the feast, especially 
after the remaining acorns fall to the ground in October.

Making waves: Most red oaks produce a bumper crop simultaneously across much of the province, roughly once every four years, though this timing can be influenced by the weather, such as a late spring frost. The last banner year was 2008. Conserving its resources, a tree may produce just a couple of dozen acorns one year and several thousand another. The effects of this cycle ripple through the forest, with high nut yields increasing everything from winter deer survival and black bear reproduction to bird nest predation (due to rising rodent populations and subsequent food shortages). The northern range of acorn-dependent southern flying squirrels, which has expanded rapidly across central Ontario in recent decades, was thrown back some 240 km by a particularly 
bad crop in 2003, followed by a severe winter.

Neglectful propagation: By fruiting heavily once in a while, red oaks produce more than enough acorns to go around, leaving some to start new trees. However, because the nuts are relatively heavy, they depend on their consumers for dispersal. Squirrels, chipmunks, blue jays, and mice carry acorns away to winter food caches, and those they fail to retrieve may germinate in the spring.