For the Birds Radio Program: Bird Bodies
What makes a bird a bird?
This weekend marks the 33rd anniversary of the day I saw the first bird on my life list—a Black-capped Chickadee in Baker Woodlot on the Michigan State University campus on March 2, 1975. Considering that I needed two field guides and a bird recording in order to identify that common bird, I’m not in a position to ridicule people who don’t know a hawk from a handsaw. But sometimes it’s hard for me to remember how little I knew about birds at that point, and how little most people know about birds. Once when I was at the Minnesota Zoo, I overheard a kindergartener asking his teacher if the swans in a nearby pond were birds. She said, “You know, I’m not sure. We can look that up when we get back to school.” I was even more horrified back in the 80s when Duluth Audubon held a forum about the exploding gull population along Lake Superior. One Duluth anchorman came to my house to interview me before the meeting, and as he was getting his sound levels, he asked, in all sincerity, if it was true that gulls were a kind of bird. I felt sad that our educational system is so focused away from the natural world that it’s easy to become well-educated without knowing basic, common birds, and without being certain what a bird even is. In both the advanced high school biology class and the college biology class that I took, we spent weeks and weeks learning myriad unicellular organisms and then bazillions of different kinds of worms, but we didn’t get around to birds or mammals till the last couple of weeks, and never did focus on familiar species. From an intellectual standpoint, it makes logical sense to start with one-celled creatures and slowly work toward ones with more complexity. But from the standpoint of the real world, it would probably be easiest for most people to grasp basic biology if we started with the plants and animals we encounter in our daily lives.
Anyway, although I’m sure that teacher would have guessed that the swan was a bird had she seen it in flight, a swimming swan doesn’t look anything like a robin. Its dense white plumage doesn’t show off individual feathers. Penguins look even less like birds—many times I’ve heard educated people refer to their dense fur, though they, too, are covered with feathers. Most people of course realize that gulls are birds, but even that fact clearly eludes some successful and ostensibly intelligent people. From hummingbirds to ostriches, feathers are the one thing that all birds have and no other animals have—the single feature that defines the entire class of animals. Speaking of which, many times people say “birds and animals,” as if birds weren’t animals. Usually when people say that, they are using the word “animals” to refer to mammals. But the word animal refers to any living thing that isn’t a plant, virus, or bacteria, so it properly includes birds, insects, spiders, and even us.
Birds are considerably different from us, but we mammals share a lot in common with them too, as warm-blooded vertebrates with large brains and a huge capacity for learning. Birds are of course specially adapted for flight, so their bodies—especially their respiratory, circulatory, digestive, reproductive, and nervous systems–have unique adaptations and surpass ours in efficiency. In coming For the Birds programs, I’ll be exploring bird bodies, from chickadees to emus—how they work and how they compare to ours—and I’ll also continue to dream of one day living in a country where everyone knows for sure that swans and gulls are, indeed, birds.