This is a story from the Hitopadesha.
Long long ago in the forests of central India , there was a huge banyan tree. The tree was house to hundreds of birds who had built nests on the innumerable branches. All the birds left the tree during the day to look for food and came back by nightfall.
During a particular time of the year, lots of chicks had hatched on the tree and the parent birds were compelled to leave them and go to look for food.
One day, late in the evening, a very old vulture by name Grudhra , battered by age and could barely fly , came to the tree. His eyesight had also become very bad due to his age . He was walking very slowly and was almost about to hit the tree when some of the birds saw him. He was a huge figure and they were frightened by him but soon realised that he was almost blind and had blunt claws and beak and so could not harm anyone.
Some of the bolder birds came down and asked him ” Who are you Sir and may we ask what you are doing here??” The vulture said “My name is Grudhra and I am an orphan. I have become very weak due to age that I have to struggle to get food every day. I have not had food for days and have come wandering in search of food.” The birds felt pity on him and offered him a deal. They told him, “Sir, we have our chicks on the tree and we have to go out the whole day for food and there is no one to look after them. So if you stay in the hollow at the bottom of the tree and look after our chicks from danger while we are out, we shall bring you food everyday”. Grudhra was happy and he agreed to the deal.
Accordingly, from the next day, the vulture used to come out of the hollow and stand under the tree the whole day and the small animals like fox and cats who were on the prowl to hunt the chicks were intimidated by the imposing figure of the vulture and kept away. In the evenings the birds used to bring food for the vulture. This arrangement went on well for quite some days and both the vulture and the birds were happy.
One day a cunning cat by name Bidaala slowly came near the tree. He had seen so many chicks and was very eager to devour some of them. But suddenly he noticed Grudhra and was taken aback. He thought the vulture would pounce on him and he would be minced meat in moments. But to his surprise, Grudhra slowly turned around and in a deep voice asked “Who is there???” The clever Bidaala understood that the vulture was blind but he could not underestimate the power of a vulture. So he said in a meek voice , “I am a mendicant cat by name Bidaala and I am on a yatra to see the holy places in this part of the country. Sorry if I have disturbed you Sir”. Grudhra could not see the cat clearly and the voice of the cat was so meek that he believed what he said.
“Oh! Welcome. I am Grudhra , an old vulture and guardian of these birds” said the vulture. “You may be my guest in the hollow of the tree where I reside for as many days as you please Sir.” he continued. The cat said ,”Oh! call me Bidaala. I am much younger to you Sir and it is my good fortune to serve elderly souls like you”. Grudhra was very pleased as he had got a companion to talk during day time.
Slowly Bidaala won the confidence of Grudhra. He stayed in the hollow being careful enough to come out of the hollow only when the last of the birds had left and go back in before the birds came back in the evening.
One day he tried his fortune and deftly caught a chick by its neck from one of the lower branches, so quickly that it could not make noise. Swiftly he ran into the bushes and devoured the chick. All the other chicks made lot of noise but Grudhra could not see any animal nearby and soon the noise died down. This started happening once in three days and later became more frequent. The parent birds noticed the missing ones but were at a loss to find out who was behind it. Bidaala was careful to leave the bones in the bushes.
One day a crane who had also lost one of her chicks happened to see the bunch of bones in the bushes. Coincidentally, the vulture was not able to eat much food in the evenings as he was feeling little sick. The crane told the birds of the heap of bones and they came to a conclusion that it was Grudhra who had devoured their little ones and therefore was not eating well in the evenings.
Poor Grudhra! The birds had unanimously decided to attack Grudhra and they swooped on him, swarmed around him pecking him with their beaks and claws making lot of noise .Grudhra tried to protest as Bidaala watched in horror from the hollow. Finally, Grudhra, not able to bear the attack sank and fell down senseless. He could not speak and life was ebbing away.
Then , the birds flew up the tree their anger still simmering. Just then, Bidaala slinked out of the hollow and started running towards the bushes where he used to devour the chicks. The birds , only then noticed Bidaala and understood that it was Bidaala, not Grudhra who was the real culprit.
Alas! it was too late. They had killed a member of their own clan who was innocent and was so old.
P.S. This happens with us human beings too. So choose your friends carefully and do not act in a haste.