Is it forbidden to eat an animal or a bird that is not permissible to eat if a person is obliged to do so,…

Is it forbidden to eat an animal or a bird that is not permissible to eat if a person is obliged to do so, such as being in a forest or a place where there is nothing but these animals that are forbidden to eat? For example, he saw a rabbit, a hawk, or an eagle, and he caught them, then cooked and ate them. Will he sin knowing that he is obliged to do so? The rule says "Necessity knows no law"?