In reply to purplemonkeyelephant:
I know what you mean. I saw a very sick-looking raven one morning last year in Camp 4; over the course of an hour it got worse and finally stopped moving. It was attended all the time by a number of other ravens who came and went. When it became unresponsive one of them bought food and tried to feed it. They pecked at it gently before I took the corpse away from camp so other people wouldn't interfere with it.
These are very intelligent creatures, totally unlike us. Their lineage is closer to that of dinosaurs, different parts of their brain perform higher cognitive functions to mammals and they even have different kinds of colour receptors in their eyes (mammals had to re-evolve colour vision after spending aeons being nocturnal). If we ever meet intelligent, off-world aliens the experience may be like that of looking into the eyes of a raven: strikingly similar but utterly different.