Wildlife officials reported recently that approximately 1,500 eared grebes died in a bizarre accident in a Walmart parking lot in Cedar City, Utah. Another 3,500 grebes were dazed and confused; they were gathered up by volunteers and later released at a nearby lake.

Though grebes are water birds similar to ducks, they have lobed toes, not webbed feet. Plus, grebe legs are positioned far to the rear of the body, making them even more ungainly on land than ducks.

According to the American Bird Conservancy, eared grebes migrate later than any other North American bird. And they only migrate at night. So a large flock of migrating eared grebes in December was not unusual. But the circumstances were.

It was a dark and stormy night. Visibility was poor. Christine Sheppard, ABC's bird collision program director, thinks this led to the mass grounding.

"Night-flying birds use dim light from the moon and stars and the earth's magnetic field for navigation," Sheppard said. "Adverse conditions on [Dec. 12] may have caused the same kind of disorientation that can afflict pilots in the fog -- the birds may have flown directly into the ground, not realizing they were descending."

A lake or river is usually safe haven from a storm, and from above in poor light, the dark wet parking lot may have looked like a body of water.

On a much smaller scale, I witnessed a similar event several years ago. I was driving on a winding, paved, ridge top road early one morning. There had been rain and dense fog the night before. I noticed a dead bird on the road that I did not immediately recognize.

So I stopped and picked up a pied-billed grebe in perfect condition, except, of course, for the broken neck. Given that the road was on a ridge top and far from water, I concluded that the grebe had tried to land on the road, which it had mistaken for a stream or river.

I guess even birds experience pilot error.