A vigorous belt of chilly rain passed over Sewanee this morning. In its wake, a Canada Warbler feeding on the shrubs in our garden. This is a bird of the boreal forest, found here only during migration. Cool rain, falling temperatures, a forecast for a week of low humidity and clear sunny skies, and the Bird from the North: these all speak of the season’s change.

The plants are ready. Many local species make use of the autumnal surge of birds to complete their pollination and seed dispersal. Cardinal flowers bloom along lake edges, beckoning hummingbirds with their crimson blooms. Dogwood and beautyberry offer brightly colored fruits to the passing thrushes, vireos and warblers. These birds feed on North American insects all summer, then become frugivorous on their tropical wintering grounds. They start the fruity feast right here, gobbling the fruits of our native shrubs and depositing the seeds a few hours later.

One of the most abundant of these fruiting shrubs is spicebush (Lindera benzoin), a species that is particularly common on the mountain slopes. This has been an incredible year for spicebush. I’ve never seen so many fruits. The warm spring must have suited them.

Like Christmas trees loaded with goodies, the plants will be stripped bare when the party gets going. For now, they sit in a quiet forest, waiting for the rambunctious guests to arrive. But unlike the treats on Christmas tree which make up just a small part of the festive food, these berries are the main meal for migrant birds. Now that dogwoods are nearly gone from our forests, killed by an invading fungus, spicebush is a lifeline for the feathered travelers.