Make a purple martin house from a gourd. drill a 2 inch hole in the bottom,remove the seeds and dry the gourd completly. Plug the hole ,drill a couple holes for draniage and create an entrance hole on one side 21/2 inches in diamter paint the gourd and hand amoung a batch of them and sit back and waite. And wood is always the best>>>>>>>
If you have a choice, use wood. They are also attracted to sites with ponds/lakes if that helps. They live communally, so you will have to make more than one house and cluster the nests together to attract them.
wood always for birds,,its better for them ..then a a hot metal kill box...good luck
With the bird houses , is it better to have the wood , or they make one of mettle , which i was given, i worry it might be too hot ? Any help on theses birds and their houses would be wonderful , thanks so much. Happy Summer !