I can see that you are quite puzzled by our riddle, Wondernose. Why ever would a bird fall over Niagara Falls?
To explain why this can happen, I must introduce you to a scientific term called “wing loading.” Different sizes of birds have different wing loadings. If you want to figure out a certain bird’s wing loading, you have to take its body mass and divide it by the surface area of the wings. Basically, what you find out is how many pounds each square inch of the wings must carry. A bird with large wings and a small body will have a low wing loading. On the other hand, a bird with small wings and a large body will have a large wing loading. Obviously, if the wing loading is too high (such as in the ostrich), then the bird simply cannot fly.
Now, getting back to Niagara Falls…our mystery birds have a fairly high wing loading. They nest in the Arctic, but, for the winter, they migrate all the way down to the central east coast of the U. S., as far as North Carolina. Their migration route takes them near Niagara Falls. If you’d happen to be there at the right time in the spring, you might see dozens of these birds landing on the Niagara River above the falls.
Our mystery bird’s body is heavy—up to 20 pounds (9 kg) or more. Even though it also has large wings, getting a body that size into the air is quite a chore. This bird has four times the wing loading of a crow! The bird has to patter over the water, following the wind direction, for quite a distance, before it becomes airborne. Now can you see what might happen, Wondernose?
Suppose the wind direction is downriver. Unaware of the mighty rapids in the Niagara above the falls, our bird may go too far in its pattering. Suddenly it is caught in the fierce current. Down over the falls it goes, losing its life.
So you are thinking this must be a goose, Wondernose. You are not far wrong. Our mystery bird is obviously a waterfowl. In fact, it’s one of North America’s largest waterfowl. It has a long neck…
Right. Our bird is a swan. Its full name is Tundra Swan (also has been called Whistling Swan). Those are the only swans that nest in the far North. No doubt you’ve also heard of the Trumpeter Swans. The Trumpeter and the Tundra Swans are very much alike, both being white with black bills.
What are the differences between Trumpeter Swans and Tundra Swans? The Trumpeter is larger. It can weigh 30 pounds (14 kg) or even more. Trumpeters don’t nest in the Arctic. Years ago they used to nest all over North America. Then their numbers became greatly reduced. At one time only one hundred or so Trumpeters remained!
Through careful conservation, Trumpeter numbers were brought higher again. Today there may be several thousand in southwestern Canada and the northwestern states. As you can guess from their name, Trumpeters have a very distinctive call. Tundra Swans have a similar voice, with an added whistling note that helps to identify them. Do you know why these swans have a trombone-like cry? Because their windpipes go up through their long necks in a spiral pattern!
Do you know what baby swans are called, Wondernose? Yes, cygnets. Swans nest on a heap of vegetation near the water. Both parents take turns at brooding. They guard the nest well. Like geese, they will let out a note of triumph after chasing off an enemy.
Did you know that cygnets have only short necks when they hatch? A few hours after hatching, they can run and swim. The parents still take good care of them, however. Some adult swans give their babies rides on their backs when they swim. It takes two or more years till the immature birds develop the pure white plumage of the adults.
What do swans eat? Mostly plants, uprooted from shallow water. They also take small fish, tadpoles, and insects. They don’t dive; their long necks serve well enough to gather food from underwater.
Most swans live in the Northern hemisphere. But down in South America we find the Concoroba Swans. If you think that all swans have long necks, Wondernose, then you wouldn’t recognize the Concoroba as a swan. With its shorter neck, it looks a lot like a white duck. Other swans of the Southern hemisphere are Australia’s Black Swan and South America’s Black-necked Swan.
Over in Europe and Asia, the most common swan is the Mute Swan. Do you know what the word “mute” means, Wondernose? Right—a mute person can’t speak. But Mute Swans are by no means silent. They grunt and hiss a lot. They just don’t have the “trumpet call” of the North American swans.
In other ways the Mute Swan is a lot like the Trumpeter. One difference you’d notice, though, is the Mute’s big black knob above the beak. And the Mute’s bill is red in contrast to the Trumpeter’s black.