During a snow squall a few days ago, a great winged thing flew into a high tree behind our house. Too far away to identify, it was nonetheless instantly recognisable as a bird of prey, its flight and landing signaling warning and an almost subconscious tricking of alarm. The starlings that had flashed like motes of dark against the snow vanished; the neighbourhood grew utterly silent. Only the scraping of one branch against another and a sudden drift of snow marked the great bird's departure. Although I was inside the house, my head filled suddenly with the heavy beating of wings.

Every winter we feed a population of starlings, cardinals, sparrows, blue jays, chickadees, and finches. The little finches caper at the feeder hanging outside my office window; the larger birds eat what they kick down to the ground. The starlings eat the cat food we put out in the alley for stray cats. Occasionally, on frigid winter days, something the size and shape of a kestrel appears and soon slips away. When crows come, less frequently these days, the smaller birds scold and chase them away. But no birds stayed in the presence of this great bird of prey.

According to an Egyptian legend, Horus, the god of the sky who took the form of a falcon, ruled both the sun and moon. And it is true that on the day this great bird visited us, a weak sun bled itself upon the snow before the full cold moon waxed into fullness that very night. The city lay haunted beneath the shadow of this visitation.

In the morning the great bird returned, closer this time, and I saw that it was a falcon.

The second day of February is considered the turning point toward spring, a moment when we pause to measure the return of light. But this day is also the middle of winter, and spring remains as distant as the fall behind us. And it is hardly a surprise that we measure the day with shadow as well as light. The shape of a storm cloud, the cast of snow against dusk. Or the shadow of a great winged predator in the deep of winter.