They do.

The boxes are very popular around here.

If you get one of those fancy houses that looks like an antebellum mansion (sort of) be aware that only one out of every three "apartments" will be occupied. There's something about the proximity. They want more space and not so close neighbors. (I can relate)

I like what the Amish do around here. They get birdhouse gourds, drill the holes to the Martin specs, and hang them EXACTLY far enough apart for the Martins to find acceptable.  They paint the gourds white, and they actually look really cool hanging on the cable.  (They sink two posts about 20' high (which means a longer post) and run a cable between them, with the gourds strung on the cable. I don't know how they manage keeping them spread out, but that shouldn't be too hard.)

Anyway, they don't have every one filled, but they have higher than average populations, and they have a lot of Martins.

I have not done this for years because Martins love honeybees and I'm a beekeeper.  But my dad kept Martin boxes up all the time, and I loved watching them hunt.

Of course..they hunt everything...beneficials as well as the "bad" bugs.  None of that matters to nature. Our interference is what makes some things bad and some not.

I love Purple Martins and would like to have some boxes.


ETA: Great thread topic, and welcome to the forum!

Yes, that was our experience as well.

Sounds like you have some personal experience?

ETA:  And sounds like there should be a means of lowering the box/gourd cable to clean it out each year?

I remember my dad had a collapsing pole. I'd forgotten that until you mentioned this.

Baby barn swallows are really cute. There's a phase where they look just like little vampires staring over the edge of the nest, complete with cape adn everything.