I think the main theme in 'Wild Swans Short Story' is transformation. The swans are often symbols of grace and beauty, but in a short story context, they could be used to show how the characters or the situation transform over time. Maybe the characters start out in one state, perhaps naive or in a difficult situation, and as the story progresses, they change, much like how a swan goes through different stages in its life. There could also be a sense of mystery associated with the swans, which adds to the overall theme of transformation as the characters try to understand the swans and in the process, understand themselves better.
Well, one of the main themes is probably survival. The swans in the story might represent the characters' need to adapt and survive in a harsh environment. They have to find ways to deal with the various difficulties that come their way, whether it's related to nature or human - made problems. And also, there could be a theme of freedom. The swans are wild after all, and the idea of being free and not being caged or restricted might be an underlying theme.