Most of us love a good mystery, and in books and movies if we can’t figure out the solution ourselves the secret is revealed to us at the end. Mysteries in real life, though, are not always resolved so neatly.

This morning, I was standing at the kitchen sink rinsing breakfast dishes, when a shadow passed directly over the house. I looked out the window and saw a bird flying overhead. Hoping for a better look I rushed to another window where, by craning my neck into a very uncomfortable position, and looking up high, I got a quick look at the bird as it turned and disappeared over the trees. It had all happened very fast, and in those few seconds I managed to see only that it was a large bird with both light and dark plumage, and long wings. What was it? I had just enough information to feel completely puzzled about what I had seen.

A good way to begin identifying birds is to first eliminate the least likely ones, so I began to think about large birds that might be in our neighborhood at this time of year. The first big bird that came to mind was a crow, but this bird was much larger than a crow. Then I thought about ravens, which are almost two feet long, with a 4 ½-foot wingspan, much larger than many folks realize. Crows and ravens are black, but this bird had a lot of white on it. It could not have been a crow or a raven.

Next, I thought about a turkey vulture, since a few days ago I had seen the first ones of the season circling above the hill across the road from our house. When soaring or gliding they hold up their wings in a distinctive “V” position, and when seen from below the two-toned underside of the wing is very noticeable, with the leading edge dark and the trailing edge lighter. This bird had none of that. It was not a turkey vulture.

Could it have been a Great Blue hHeron? A couple of days ago, I saw two of them, so they are coming back for the nesting season, but I did not see any of the markings or coloration of the Great Blue , and there were no long legs trailing out behind as it flew away. It was not a Great Blue Heron.

As the list of possible birds got shorter, the mystery was no closer to being solved, so it was time to widen the search. I thought then about the fact that the ice had gone out of our lake on March 23, weeks earlier than usual, and I thought about two birds that are closely associated with open water. Bald eagles, who spend the winter near open rivers or along the coast, come inland when the lakes open up to fish, and to hunt ducks. We had seen a few eagles in recent weeks, and it would not have been that unusual for one to fly over our yard. Although this bird did not have the white head and tail of an adult bald eagle, young eagles take four years to mature, and vary widely in appearance. First-year birds are dark brown, but as they age they develop white feathers on the body and can look quite mottled. At all ages, bald eagles show noticeable white areas underneath, where the wing connects with the body.

The other bird closely associated with open water is the osprey, a bird we see infrequently during migration. It has extremely long narrow wings, which appear to be bent back at the wrist (a bird’s wrist is about half-way out the length of the wing), its back is brown, it is white below, and the underside of the wing is white and brown.

Sometimes, we get a good long look at a bird and can identify it with confidence, but at other times we are left scratching our heads, even after thinking of the possibilities and consulting field guides for more information. In this case, seeing the bird for only a few seconds did not provide enough clues to its identity, and I had to admit I was left with an unsolvable mystery.