What does the story imply about human nature and how we treat one another?
The story seems to make very clear that human beings can be very self-centered and comparatively uncaring of others who are different from us. During the entire time that the old winged man lived in the chicken coop, nobody seemed to care about his comfort. Many people came to be amused by him and some of them even tormented him by throwing stones at him and even burning him, just to see his reaction. There is a very good argument that it is highly immoral to treat animals cruelly or to raise and slaughter them for food in ways that are inhumane. This story seems to suggest that this type of insensitivity is not something that people only express toward animals, but also toward one another.
Except for having wings that made the old man different from other people, he was a human being.
Chances are if the same old man had been found by Pelayo and Elisenda under the same circumstances but without any wings, he would have been treated much more kindly. However, the wings made him different enough from them that even though he seemed to be completely human in every other respect, that difference prevented anybody from caring about him or having any compassion toward him. Even when he finally flew away, Elisendas main thought was that the old winged man had been a burden to her. On the other hand, she seemed to know on some level that he was a pathetic creature because she felt relieved for him. The story suggests that human moral concern should not be so dependent on “sameness”; all living things are entitled to our compassion, even animals and even creatures of unknown nature.