http://www.purplemartin.org This is a Pre-migratory roost of Purple Martins in Louisville Kentucky on August 5, 2013. Just over 12 minutes, see how visiting a roost near you would be a great way to say farewell to your Purple Martins. Purple Martins nearly totally depend on man for nest sites. All of these Purple Martins came from backyard colonies from people that enjoyed them all summer. Consider adding martin housing near your garden or backyard. They litterally do not nest anywhere but in human supplied nest sites. A video by Larry Melcher.