A wild dolphin near Hawaii that had gotten entangled in a fishing line sought help with a few divers and not only allowed them to remove the line but even tried to help them by moving into the right position:
In my opinion the dolphin
1) was aware that the line was human-made
2) knew he (or she, rather, I think. The video is a bit dark) couldn't get it off alone
3) realized that removing a man-made thing might require fingers (and the human attached to them)
and consequently approached a human.
In other words, the "dumb animal" thought, analyzed the situation, drew conclusions and acted on them. Something many children would not have done.
However, some might claim the dolphin acted purely on instinct or by coincidence.
What do you think? Are dolphins a sentinent species? Should they been given protection? Should they be treated different to other protected species, possibly even given the same status as humans? How about the other whales?