The rains we’ve been waiting for, yearning for, have finally arrived in our part of Tennessee, and the sugar-maple leaves are falling now in great clots. Rain is falling and leaves are falling and my youngest son, like his brothers, has received his Selective Service card in the mail, and today I have returned to my house to find a lone black vulture standing in my front yard.

I am always grateful to vultures, that indefatigable cleanup crew doing such necessary work along the roadsides. Nevertheless, a vulture adopting an attitude of possession toward my own home does not exactly constitute a welcome autumn tableau, especially not during a melancholy week of rain in the window and inescapable images of war licking at the edges of a mother’s mind.

We live on an unkempt half-acre lot in a neighborhood where most of the lawns are pristine, and vultures are not common visitors. Yet here is one standing a few feet from my own front door. I idle in the driveway to watch. It is eating nothing. It is only standing there, looking at my house. Occasionally it dips its head and hunches, mantling its wings, but there appears to be nothing at its feet, no prey to protect from encroachers. Nor any encroachers, for that matter.

I drive around back, walk through the house, open the front door. The vulture turns one side of its bald, black face to look at me through the glass of the storm door. It looks at me for some time in that peculiar side-eyed way of birds, and then it flops heavily off, low across the yard and finally up and over the house next door. When I let our old dog out, he sniffs again and again at the spot where the vulture was standing, but he comes to no discernible conclusions.

I have never seen a solitary black vulture before. Unlike turkey vultures — they of the garish pink head, they of the wingspan that forms a telltale V in the sky — black vultures have a poor sense of smell and tend to follow turkey vultures around in their search for food. In fact, there is a newly dead chipmunk in the street only yards from my front door. I noticed it on my way out this morning, but the black vulture has not noticed it. I think it must surely have registered the dead chipmunk’s existence at some visceral level, that surely the dead chipmunk is what has summoned this bird to my yard. The chipmunk has been a sort of housemate of mine, living in an elaborate tunnel system under the foundation, and I don’t like to think of it lying unmourned in the rain-soaked street. I step back from the storm door and wait, hoping the vulture will come and claim its prize.

But these are willed thoughts, a hedge against an atavistic instinct to read omens and signs into a giant black vulture that has staked out my home on a day when the federal government has announced its intention to claim my child. I think of myself as a rational person. I am not a reader of portents or horoscopes, and I greet the promises of fortune cookies with wry hope at best, but there was a time, more than 20 years ago, when I once hand-delivered 20 copies of a chain letter on the last day before bad luck was supposed to descend on anyone who dared to break the chain. I was not in my right mind: I had recently suffered two devastating miscarriages and was precariously pregnant again with a child that no one expected to live. I stuck a bunch of chain letters in the mailboxes of people I did not know, just to be safe.

That child registered for the Selective Service two years ago, and now it is his younger brother’s turn. If a simple card in the mail can cast me back into the ancient reach of augury, I can only imagine the dread that claws at the heart of a mother whose child is serving in a part of the world where dangers are real and not merely imagined — where fear is of a piece with sacrifice and not of superstition.

I know a vulture is only a bird, only a bird and not an omen, no matter the temptation to turn it into the equivalent of Poe’s raven. Arriving shrouded in widow’s weeds and standing in solitary magnificence to stare at me with one unblinking black eye, it is still only a bird, a big, black bird entirely indifferent to the workings of the human realm. Unaware of the workings of the human heart.

When I leave to walk the old dog after dark, the unlucky chipmunk is still lying in the road where it met its end. The next morning I wake up late. When I finally sit down at my desk and look out the window, there’s not one trace of the former chipmunk clinging to the asphalt, not one glossy black feather resting on the grass.