 In the early 1960s, numbers of purple martens were on the decline as natural habitat was lost. As Brian Fitzgerald explains, in Griggsville, Illinois, TV antenna manufacturer J.L. Wade was inspired to begin creating houses that would cater to the bird. They're a colonized bird. They feel safer in numbers, and they want to be in groups. So the houses that J.L. Wade made, they housed 12 pairs of martens.