The balancing bird is a toy that has its center of gravity located at the tip of the beak. The center of gravity (also called the center of mass) is a special point on an object. It's the point at which the mass of the body is perfectly balanced. For example, the center of gravity of a pencil is in the middle. So you can hold a pencil up using just one finger if you place it underneath the middle of the pencil. Similarly, you can hold the bird up using one finger as well, if you place it underneath the beak.
Check out a video of the bird:
It might seem strange that the bird is perfectly balanced at the beak location. But this is because the bird is designed this way. The wings are extended in front of the beak far enough, and made heavy enough, to balance the weight of the bird behind the beak.
In most objects it is not clear where the center of gravity is. If an object has a strange shape then you cannot know by looking at it where the center of gravity is. If an object has a uniform shape, like a pencil, or a square, then the center of mass is easy to determine. It's in the center of the object. But for objects with non-uniform shapes this is not known ahead of time. To find the center of gravity for these objects you need to use trial and error. You must try balancing the object on different points until you find the point where the object is perfectly balanced, and doesn't fall over. This point, once found, is the center of gravity.
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