Some symbols are universal, established and understood by people's through time and place. Others are emerging and signify different meanings and associations. Our cultures make these connections, but, as far as we've come to know, Islam, unlikely. As for the owl, my understanding of your question was the same - I thought you meant in a dream. I once read a similar question that had been asked about the symbolic meaning of the dove in comparison to Christianity, which signifies peace and the holy spirit. If I remember correctly, the answer focused on two main things: one, that the dove is a bird made permissible to eat, and that peace and justice has been established as a command of Allah, not through an object. So, in Islam, even though people proclaim the crescent and the star to be our symbolic representation, we don't associate symbols with our religious commands. Everything is plain and clear and meaning can be sought here.