The big cats have decided to leave

Vix stood at the bank of a wide river.
The slow waters passed by the sandy landscape in soundless, swirly patterns.
Countless big cats of every variety flanked him on the riverbank; tigers, panthers, lions, leopards, lynxes and cougars - every feline he could name seemed to be represented, and even some he didn't know the names for.
A big black cat turned to him and spoke in a booming voice, with unmoving lips:
"We have decided to leave now."
Vix didn't have a clue about what the cat was saying, but answered:
"That's very sad. I would have loved for you to stay."
"I'm sorry", the black cat said, "but there is nothing for us here anymore. There's simply no other way."
Vix felt the sadness grow inside as he heard the great black cat utter these words. He didn’t know why, but quietly replied:
"Ok then. I guess I won't be seeing you."
"No", the cat said.
One by one, the cats walked out into the river. As they entered the water, the elder cats laid their paws on the heads of the younger ones and pushed them beneath the surface. Then they forced them down until they could breathe no more.
There were some terrible sights. Some of the young ones were fighting and panicking under the weight of the elders, shuddering and flailing their paws under the water, struggling for air with their final strength of their will to live.
But one by one they ceased fighting, and as the movement of yet another animal faded, the stillness of the slow stream of the river became the only movement left.
Then the older cats then swam out into the middle of the river, and as they reached it he saw them giving up to the silent undertow one by one.
Vix stood on the riverbank watching the last big cat die.
He was crying.
Cats can't cry.