What am I by the River?

What am I? asked the rabbit, nimble and swift,

As he gazed into the rippling water.

I know. I'm a fish and I can swim,

The rabbit jumped but did not make it.

What am I? asked the fox, clever and cunning,

As he gazed into the rippling water.

I know, I'm a bird and I can fly,

The fox leapt but did not make it

What am I? asked the Author, clear and concise,

As he gazed into the rippling water.

Of course I'm human, so I'll make a bridge

The Author made it across.

What difference is between these three,

For animals they be.

There isn't one because, you see,

These animals are me.