In another article, I explained what purple martins are and mentioned the fact that their numbers declined enormously when European starlings were introduced to North America. This is mostly because of competition for nesting sites. Starlings and house sparrows will nest in the same sort of structure that purple martins nest in.
Because of this, in the eastern US, purple martins are almost totally reliant on people for their nesting sites. Some people might want to know how to attract these birds, how to set up nesting boxes, and how to maintain them. This is a clip that is just over eight minutes long and it is a great first step for setting up a place for purple martins to nest.
In fact, it is worthwhile to view even if you are just interested in birds but have no interest in setting up nest boxes. Additionally, some of this information is insightful for setting up nesting boxes for other wild birds, too.