Our resident barn swallows seem to have all left, except for one. The others have been gone for days, but this little guy/gal is still hanging around. S/he seems healthy, is flying and complains when we open the front door and disturb him. We've had swallows nest under the roof in our entry way for 8 years, and they always seem to leave together. We've never had one "left behind" before and I am concerned. So I am wondering about their migration patterns, do they usually all leave together, and does anyone else here have any stragglers?