The more we learn about animals, the more it seems our way of treating them is immoral. (But then, that's true about gaining knowledge of pretty much everything.)
A crow that used multiple tools to accomplish a task:
And here's a surprising reaction from a dolphin. There may be some anthropromorphization in this interpretation, but what if there's not?
Let me tell you a story. One of the first dolphins I ever worked with was Circe. I’d bring her a fish when I wanted her to do certain things. If she didn’t do them, I did a “time-out” where I turned my back and walked away. Well, there was a certain type of fish that Circe loathed because it had a spiny tail. So I accommodated her by cutting the spines off of the tail. One day, I forgot to do that. Circe spit it out, swam to the other side of the pool and placed herself into a vertical position that mimicked my time-out. I wanted to test this. I gave her untrimmed fish on four different days. Whenever I gave her fish with spiny tails, she gave me a time-out. What that suggested was that she saw time out as a correction and used it back on me. Well, that’s how we learn to communicate.
-- Diana Reiss, interview in the New York Times