Orcas are mammals because they give birth to live babies and they feed their babies with milk from their body. They are endangered species. They live in all temperatures of the oceans. These mammals are most at risk for poisons from our toxic waste in the ocean.
When I was almost 3 I went to Sea World. I saw an Ocra then. It lived in captivity. The captive whales have curved fins on top of their bodies. The orcas were playing and did tricks together.