Avian alien race from Walter H. Hunt's Dark Wing series.
The zor is just one of the alien races that humanity encounters when it travels to the stars, and from the very first meeting it has been all-out war. For many years the conflicts have been sporadic, usually ending with an Earth concession and a treaty. But the zor do not respect mankind and has no any intention of honoring the agreements.
An bird-like alien race, they are very fanatical, untrustworthy and war-like.