This is article has necessary information you need BEFORE you buy and set up housing for Purple Martins. So if you are ready to establish a Purple Martin colony, for your pleasure and their survival, read on!
If you don’t know what you’re doing, you are apt to waste your time and money trying to attract Purple Martins. You need the right kind of housing and you need to set it up in the right way and at the right place. Many people get all set up with martin houses, and yet don’t get any birds using it. There are several reasons why, and I hope that when you’re armed with information, you won’t make the same mistakes.
Where Do You Live?
The Purple Martin breeding range can be seen here. Checking the map, you can see if you’re within range and thus have the possibility of attracting Purple Martins.
Is Your Even Site Suitable?
Believe it or not, there are certain space requirements for setting up Purple Martin housing. If there isn’t enough open space, they won’t use the birdhouses. Tall trees near the houses will discourage the birds as well. If your yard is too small, you will waste your money investing in Purple Martin housing…unless of course, you want to provide homes for Starlings and House Sparrows. You may get lucky and have some wrens and Tree Swallows also take up residence. But you won’t get Purple Martins unless there’s a lot of open space around the birdhouse.
How much space are we talking here? Martins prefer open areas. If you have a large open area, place the martin house at the center of it, and it should be around 30 feet or more from human housing—though further than 100 feet isn’t desirable either, as the human presence will help discourage predators. The martin house should also be at least 40-60 feet from trees. At least! They will not use nest boxes which are closer than 40 feet from trees, as they require a wide margin of “flight space” all around. Even one large tree near the housing will discourage them from using it.
One approach used by those who live on a lake or pond and don’t have a lot of room on land, is to make a wharf or dock extended out far enough to place the martin house at the end of it. As long as there are no trees within the prescribed distance, it will work.
As to what direction to face the entrances, it really doesn’t matter unless your area is prone to strong winds and rainstorms, in which case, orient the house so the entrances don’t face into prevailing winds. In my area, summer winds mostly come from the West, so I’d be sure to face the entrance towards the North, East or South.
What Kind of House is Best?
There are several choices. One type is a more traditional wooden house, with multiple “apartments” in it. These can work quite well, and will probably be used if all other requirements are met.
Another is a more modern style, sometimes made of metal or moulded plastic resin. These may have holes which are made to prevent Starlings from entering, and may have predator guards over the house itself.
The third type of housing uses a modern design which nonetheless mimics the traditional dried gourds used by the Native Americans who originally started providing housing for the martins. These “gourd systems” are made of UV-resistant plastic, and are easy to open, clean and inspect. These are the type most often used by professional researchers, and a colony may have dozens of gourds on one pole support.
Of course, a person could also make their own traditional gourd housing using real gourds! They need to be prepared properly and hung in a way that the birds will find them attractive, but there is no reason it can’t work–it worked well for the Purple Martins and the native peoples who started the whole trend of providing birdhouses for martins all those years ago. So successful that the eastern Purple Martins have become dependent on people to provide their nesting cavities!
Of course, if you have the space and the resources, you can provide more than one type of housing, and let the birds choose! In fact, it’s probably also a good idea to provide some single-family traditional birdhouses as well, in the surrounding area, to provide box nesters such as Tree Swallows and House Wrens a place to nest, while reserving your martin condos for the Purple Martins. If you don’t, these two species will often try to use the martin houses. At least give them an alternative.
It should be added that all poles supporting the houses, whether made of metal or wood, need to have predator guards on them, to prevent climbing raccoons, snakes, weasels, or whatever your local predators might be. Even domestic cats are potential predators to the nesting birds.
For Purple Martin houses, many prefer a telescoping pole, which can be lowered to inspect the nests and clean them out at the end of the season as well. Those who take their Purple Martin landlord job seriously will conduct regular and even daily inspections of the nests to make sure all is well. A predator situation can wipe out an entire colony, and the best way to monitor is to look in each nest on a daily basis. If there is predation noted, efforts can be made to stop it before all is lost that season.
Records of the nesting birds can be kept and coordinated with Purple Martin research teams. The reason being Purple Martins are a species in serious decline, and the more data available, the better we can help them.
One last note, it’s good to provide nesting materials. Purple Martins line their nests with green leaves and then use soft dry pine needles and straw to pad it. When the time for martins to return in Spring is near (you can use ebird to follow their migration) it’s time to open the doors for the new tenants! You can use nesting materials in some compartments to entice the martins to make themselves at home, as well as making sure those nesting materials are available “self-serve” in the immediate surroundings.