Theory:

This story is about a mother bird and her two young ones in a forest. The mother bird was taking care of her babies in a tall shady tree. One day a fierce storm uprooted many trees. A big branch hit the nest, and the mother bird was killed. But mercifully, the baby birds were blown away to the other side of the forest and were saved. One of them reached a cave of robbers. The other one settled near a rishi’s ashram.
  
After a few days, the baby birds grew up. One day, the king of the country want to hunt the animals and reached the forest. While hunting, he perceived a deer and started chasing it. The deer ran far away into the woods. Tracking the deer on a horse, the king lost his way.
  
The king kept riding and reached the other side of the forest. He got down from his horse as he was exhausted and sat under a tree near the cave. All of a sudden, he heard a voice asking to be swift and rob the person outside of his everything, including jewels, horses. The king was shocked to listen to that and looked up to look over. He noticed a big, brown bird on that tree and indistinct noises coming from the cave. Speedily he mounted the horse and ran away.
  
Soon he reached an Ashram. The king tied his horse to a tree and sat under in its shade. Here, he heard a soft voice which saluted him and asked him to go inside and take rest. It also told him to have cold water from the pot and be at ease till the Rishi comes back. Astonished, the king looked up to check and again found a similar big brown bird in the tree.
  
The bird told the king that he was ever right. The bird was his brother, but he had been looked after by robbers. He too, had become like them. The bird added that he and his brother no longer speak to each other. Just then, the rishi entered the ashram.
  
The Rishi greeted the king and requested him to come inside and relax. He also provided to share his food.

The king described the different etiquettes of the two birds who looked the same. He added that the forest was full of surprises.
 
The Rishi smiled and explained the effect of the company one has. The bird who heard robbers was repeating their words, and the one with the Rishi was speaking softly and greeting the people. The Rishi asked the king to take rest and said he'll tell him more about the birds and the place.