Human Beings Are the Only Intelligent Life in the Universe

Is it true that human beings are the only intelligent life in the universe? Human can speak language and communicate with others, think strategies, learn and remember many things. However, in my opinion, I don't think that human is "the only" intelligent life and I believe that there are many intelligent animals in the world. For example, one of the intelligent animals is crow. Crows have sociality in some degree, often cooperate with others, and communicate with others using their caws. In addition, they do some interesting actions to get their food. Specifically speaking, they drop to crash food that they can't crash with their bills on a hard ground, or they put walnut on a road and wait until a car comes and crashes the shell of the walnut. These actions can be intelligent being. I think that human is "the most" intelligent life in the world, but not "the only" intelligent life.