Although a touching analog of human suffering, you have to understand that the subtitles are fundamentally an anthropomorphizing interpretation. At an emotional level, we would like to believe that all beings are capable of the same emotions we are, but scientifically and empirically we know there is a difference in the psychological evaluation of behaviour and motivation. When we observe animal behaviour that mimics human behaviour, we are quick to infer that the animal motivations are similar to human motivation. Nearly a century worth of animal psychology shows us that this is often an incorrect conclusion. I'm not saying the interpretation is wrong, I know little about how the avian physical psychology compares to that of the human - but that it is scientifically indefensible. All of that aside, I really want to reiterate that was a touching analogy of human suffering. An experience that, recently, I can relate to.
Why is it we observe animal behavior that mimics human behavior? Why not human behavior that mimics animal behavior? After all, there is no questioning which organisms came first Our evolutionary branches have been separated for billions of years, so how is it we come to find similar behavior in animals as we do in humans? Feelings are, on a fundamental level, genetic expressions. DNA is the origin of all life, so when we search for what has "feelings", we must not exclude any life from being able to express "feeling". After all, our description for what certain feelings may be, is just a subjective interpretation. There is no objective truth to these things, because they exist within the organism and are not currently capable of being measured by science (but that's a different matter altogether) Why can't a bird feel the same love for its mother as you do yours? Why can't a bird sorrow over a death as you do? Keep in mind that it's not unreasonable to assume that other people would react differently as well, so why not other organisms? We don't have the exclusive ability to feel, there is certainly intelligent life everywhere in all forms. Sharks can smell a drop of blood in water from a mile away, polar bears are almost completely invisible under infrared (and in the snow), dolphins can recognize themselves in mirrors, chimpanzees can learn to drive Segways, the list goes on and on. Our cognitive abilities, while we haven't even properly identified them, are no more than a specific code of DNA, and our ability to pattern and organize things as we interpret them surely doesn't give us the right to assume we're the only species capable of expressing feeling...