I love purple martin houses. I love that they stand tall and regal out in the middle of pastures by themselves. They are lone sentinels that call to purple martins. I must point out that purple martins, while wonderful birds to have around because they eat lots of insects, aren't very good at finding a place to live and so must be helped along by interested people who put up houses for them.
We have had a pole full of purple martin houses for quite a few years now and haven't yet convinced any of the birds to use them. Much of it was my fault. There is a schedule to this dance I wasn't aware of initially.
First you choose an appropriate place for the houses. Then bed them with pine needles at the right time and crank them up to the correct height. Once the birds nest in your house they will come back year after year so you have to be in it for the long haul. Then you take the houses down at the right time, clean them out and put them away for next year.
Last year I was very careful with how I bedded the gourd shaped houses and when I put them up. The height was correct but no birds came to stay. We saw the purple martins on the property. We heard their song. But no nesters.
I think I may need to move the pole out farther from our growing trees. That may make all the difference. At least I hope so. I would love these guys living on our property.