Monday, April 18, 2011

The Mystery of the White-Bellied Bird on Heron Pond

A little mystery for your Monday here. Know that it will be solved by the time you finish reading.

But first a note: It was windy, overcast afternoon yesterday when the videos that tell our story were taken. I took them with my cell phone and the wind sounds really loud.
On Sunday, we decided to take a walk on a trail in one of the five areas that make up the Three Creeks Park.

Operated jointly by the Columbus and Franklin County Metropolitan Park District (Metro Parks) and the Columbus Recreation and Parks Department, Three Creeks is, as described here, "a major hub in the Franklin County Greenways program, an interconnected system of trails along the seven major streams in Central Ohio." All told, Three Creeks contains 1067-acres of scenic beauty and varied species habitat where three creeks converge: Alum Creek, Big Walnut, and Blacklick. Two areas in the park system are like conventional city parks with softball diamonds, soccer fields, play areas, and the like. The other three, operated directly by the Metro Parks, have walking trails through some beautiful scenes.

Last year, Ann and I walked through one area of the park, one affording gorgeous views of the creeks and surrounding wooded areas. But yesterday, with the sun on the wane as we headed back to Logan from visits with our families, we went to a relatively new and not-yet fully developed area called Heron Pond. It's sort of cool that this already interesting nature sanctuary sets astride busy roads so accessible and still is insulated by woods and grasses.

Chapter 1: The Mystery Presents Itself
Though only barely visible in this video, Ann and I saw strange birds we'd never seen before, lots of them. They had white bellies and black wings. (Later, we would learn that their necks are white, too.)

Their flight patterns were like those of bats. They swooped down close to the surface of the water. At first, I thought they might be like a gull, but they never dipped into the water. If fish had been their prey--and the pond apparently is home to quite a few fish, they would have seemed poor hunters.

Chapter 2: The Plot Thickens
On another side of the lake, hovering over a marsh area, along the walking trail, and near some feeding boxes set in a field, the mystery bird is more visible in this video. Like bats, they're either not intimidated or are just heedless of people being around. One bird in particular, allowed me to shoot video of it as I stood no more than ten feet away. (Sorry, I have no zoom on my cell's video function.)

At this close range, we also saw what appeared to be a bluish cast to the sides of the birds' heads. We were later told that this was merely a reflection of ultraviolet rays, similar to what you see with pigeons.

Chapter 3: That's How They Roll
Their crazy, bat-like flight patterns made Ann and me think that, like some other species of birds, these mystery birds weren't real accomplished fliers. But then we watched two of them take out over the lake, then swoop back toward us and we realized that they're versatile in their flight patterns. That's just how they roll.

Chapter 4: Mystery Solved
Even before we showed these videos to our ornithologically-informed friend, Jody, he had a good idea of who these white-bellied birds on Heron Pond were: tree swallows. The tree swallows swooped over the lake and marsh area because, like bats, they eat insects and just above the surface of the water, there's apparently a feast of gnats to be had. Unlike bats, which are mammals, of course, these birds aren't nocturnal hunters and they don't have built-in GPS systems. Somewhere along the line, God said, "OK, tree swallows you get the bugs during the day. Bats, you take the night shift."

Thanks, Jody, for solving that mystery for us.

Here is information on the tree swallow from the Audubon Society.

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