A fairy tale

A leisurely morning, I was getting myself a cup of coffee and looked out of my kitchen window. There were a couple of sparrows pecking at the grain. One stout and weathered, the other lean and agile.

But the stout bird was just staring into nothingness. It was very still. Wasn't it hungry?

Every few seconds, the agile sparrow was twisting and pecking at the stout one. When I moved closer, I noticed that the agile bird was pecking at grain and feeding the other.

Now now, it wasn't a mother, since the other bird was much larger. The stout bird was too old and would definitely feed itself by now.

This continued for some time and only when they flew away I realized that the bigger bird was injured. It was unable to bend and turn and it could not fend for itself, even from a ledge with grain.

This was straight out of a fairy tale, right?
You make up the rest of the story.