Trying and experiment with attracting Purple Martins at the lake this year. I've been using a utube video called DAWN each morning in an attempt to attract the martins. I'm also watching carefully to make sure no other birds such as Sparrows make a home. Lets see how this works!
Everything you need to know is here! From purchasing the bird houses to education. The Purple Martin Conservation Association is a great resource!
Link
https://www.purplemartin.org/