Purple Martin House - The Right One For You
Making sure that your purple martin house is large enough is a key factor. It is uncommon to have a purple martin house that is too small because most manufacturers have found that first time buyers like buying the big purple martin houses anyhow. However, I have seen some on the market that are single or maybe only four compartments large. I think these are too small. It is not because they will not come and stay, it is simply the fact that you will want your colony to grow over time. Four compartments does not allow for much opportunity to grow.Although you do not want a small purple martin house, you do not want too large of one either. This can be disappointing for those getting into this hobby. The fact is that most first time purple martin house owners will only have four or five of their compartments full. If you have a 32 family purple martin house, you have way too many spots than you will have families. I recommend going with something middle of the road, 12 or 16 compartments is fine because it does leave room for growth.
The next thing to look at is the durability of the purple martin house. Martin houses take a lot more beating than your average birdhouse. It is primarily due to the fact that they should be taken down during the winter months, they are often scrubbed down, opened and moved around, then they are outside all summer in the harsh weather with no protection covering them (it is advised you do not put the house next to trees or under awnings). Look for a durable rig. It does not have to be metal or solid wood, but something designed for this type of treatment is best.
I would recommend also looking at the doors on the purple martin houses. The older martin houses do not have the new crescent shaped doors. These new types of doors keep starlings out, which makes it a lot easier for you to attract the purple martins. This will help with other starlings from taking over the birdhouse, not leaving any room for the purple martin or simply scaring them away.