The birds flew Slower-Than-Light, but not by much, spaceships throughout the six stars and dozens of planets spread throughout Betelgeuse.  They had a thriving economy, vibrant culture, and a truly massive population.  Something like one trillion, yes with a t, souls lived in the system.  That was a higher population than every human in the Core Worlds combined.  And their population density was still lower than Earth’s.  And then there were the surrounding systems.