Suddenly, inexplicably, the hawk dips one wing, causing just the slightest hesitation in its power glide. It has intersected an updraft or, more likely, has spied something of interest on the desert floor far below. Then, just as suddenly, the bird rights itself and resumes its hurried passage. Involuntarily I glance at my watch. It reads 2:30.

Ornithologists, or maybe physicists, or surely aeronautical engineers could explain the how and the why of a raptor's momentary stall while in full soar. But I am a birder, not a scientist. I want simply to embrace the grace, the beauty, and the mystery of this hawk's mastery of the wind, not dissect it or even understand it. The experience is enough, without knowledge of the knowable. Or the unknowable. Without the reasons why things happen for a reason.

I will record this sighting, but I have no need to record the actual time. Perhaps I have checked my watch because the control freak in me dictates I do this periodically. Or perhaps I am monitoring my progress against the promised time of my return home. Even as my eyes lift again to the hawk, I know I will never see it again. In a heartbeat, in just that blink of focus, it has slipped my universe, leaving behind only its indelible memory.

Two hours later, as I book up the interstate from Tucson toward home, I feel a tingling against my thigh. It is my wife's cell phone going off in the cargo pocket of my hiking pants. No one who would be calling me knows her cell phone number. It can only be one person. She is sobbing softly. Her father has just lost, inevitably, his long and lonely battle with Alzheimer's. I pull off onto the shoulder. We share memories and tears, sadness and reminiscences. And quiet words about the genetic specter. And then, even as I realize the total irrelevancy of the question, I ask what time he died.

"2:30," she says.

It is why I am a birder.