Dear Bird Folks:
I recently saw a TV show on bird migration and have become very interested in the subject. I would like you to write something in your newspaper column about bird migration.
-Bill, Manchester, CT
Something’s Missing Bill,
You wrote, “I would like you to write something… .” Where is the question? Haven’t you noticed that this is a question and answer column? This is not “the request hour.” Here’s how it works. Someone asks us a question. I then consult with the world’s top scientists and formulate a precise answer to a specific question. Without a question I don’t know what to write about. I guess I could make up a question, but my head is so jam-packed with answers I don’t have any room left for questions. All right, let me see what I can do.
You are right to be interested in bird migration, it is by far one of the most amazing events in all of nature. It is not quite as amazing as the guy who ate fifty hot dogs in twelve minutes on ESPN a few weeks ago, but it’s close. The ability of birds of all sizes, from massive cranes to minute hummingbirds, to migrate thousands of miles has intrigued scientists for centuries. Why birds migrate, how they store enough food for the trip and how they find their way are important questions Bill. They would have been good ones for you to ask.
Why birds migrate seems like an easy one to answer. Who wouldn’t want to avoid a New England winter to spend time in the sunny tropics? But that doesn’t explain why they leave the tropics in the first place. Why would a bird fly a thousand miles north to build a nest, when it could simply build a nest were it has been spending the winter? The answers to that question are many, but much of it has to do with over crowding. By flying north, birds can exploit the wide open, food rich, bug infested wilds of Canada.
The north country provides excellent breeding grounds which produce millions of new baby birds. It is with these brand new birds that migration really becomes amazing. Think about this for a minute or even a second. Baby birds, not much more than a month or so old, somehow have to find their way to the wintering grounds. Often they do it without the help of the parents, a map, or a Fodor’s guide. At first the newly hatched birds are having the best time playing with their fellow nestlings or practicing their flying skills. Then suddenly they are struck with a case of “zugunruhe”. (Zugunruhe means “migratory restlessness”, for all of you out there who are weak on your German crossword puzzle words.)
Instantly the fun is gone and the birds start to get antsy. They eat constantly, nearly doubling their weight. Then, late one night, when the weather conditions are just right, they step off into the night sky, all alone. Flying away from the only world that they have ever known, the little birds are headed off into the pitch dark,for a place they’ve never been before. Is it me or is this starting to sound like a John Denver song?
By using the stars and directions they inherited from their parents, the birds stream south. Some birds make short flights, stopping along the way to refuel, while others fly nonstop. It’s these nonstop flights that astound me. For example, Blackpoll Warblers will take off from Nova Scotia (or Cape Cod) and fly hundreds of miles out over the Atlantic Ocean. They then take a right turn east of Bermuda and continue straight on to South America, never stopping once. These little birds, about the size and weight of a marshmallow, don’t have food, water or a second of rest for 86 hours. Wow! I’d like to see that hot dog eating ESPN guy do that.
When the warblers finally do land, they are nothing more than flying skeletons, totally depleted of all body fat. If they are lucky, the ravaged birds will find food and a place to rest the moment that they land in South America. But if Club Med has turned their wintering grounds into yet another golf course, these birds are in big trouble.
You know what Bill, we are out of room and I have only managed to discuss one aspect of bird migration. If I don’t get a better question for next week, I may continue with this migration thing, so stay tuned. In the meantime practice saying “zugunruhe”. You know you want to.