Purple martins almost exclusively rely on man made birdhouses for their nests.
Each year they migrate back to the same nesting areas as they used the previous year.
For this reason, when you look at a map of purple martin habitation, you will notice a mottle appearance.
There are some areas of the country where purple martins congregate, and other areas where they do not.
Being a purple martin landlord is serious business.
And you must choose an appropriate house for your tenants.
The two broad options are cubic-shaped houses or gourds.
Gourds are sold individually, but the poles that they are mounted on are set up to hold gourd arrays - anywhere from 4 to 24 or more gourds.
Sometimes they are strung in series between 2 poles.
Gourds can be either natural or man-made.
Natural gourds are, well, natural, and can be grown at home or purchased.
(There are several Amish farms that sell hollowed-out gourds.
) Their downside is that they do not have openings large enough to get your hand inside to clean out the nests at the end of the season.
They also deteriorate more quickly in the weather.
Artificial gourds are made of plastic, and should be white so that they stay cool.
They often have large openings molded in so that you can get inside to do nest checks or for the end of season clean-out.
Houses can be made of plastic or aluminum, and sometimes wood.
They contain compartments for as few as four and as many as several dozen martin homes.
These are mounted on poles.
Whether gourd or traditional house, you must choose between round openings and crescent shaped openings.
Round openings are easy to cut into gourds, and easy to manufacture, but they are large enough for predator birds to use.
Predator birds will at minimum, harass, or, at worst, eat purple martin babies.
If there are few predator birds, in the area, however, the round openings are fine.
Crescent shaped openings are preferred if starlings are prevalent in the area.
Starlings cannot fit through the smaller openings, and are therefore less likely to harm the purple martins.
With crescent shaped openings, you can also have perches, both on the inside and the outside of the house.
Each year they migrate back to the same nesting areas as they used the previous year.
For this reason, when you look at a map of purple martin habitation, you will notice a mottle appearance.
There are some areas of the country where purple martins congregate, and other areas where they do not.
Being a purple martin landlord is serious business.
And you must choose an appropriate house for your tenants.
The two broad options are cubic-shaped houses or gourds.
Gourds are sold individually, but the poles that they are mounted on are set up to hold gourd arrays - anywhere from 4 to 24 or more gourds.
Sometimes they are strung in series between 2 poles.
Gourds can be either natural or man-made.
Natural gourds are, well, natural, and can be grown at home or purchased.
(There are several Amish farms that sell hollowed-out gourds.
) Their downside is that they do not have openings large enough to get your hand inside to clean out the nests at the end of the season.
They also deteriorate more quickly in the weather.
Artificial gourds are made of plastic, and should be white so that they stay cool.
They often have large openings molded in so that you can get inside to do nest checks or for the end of season clean-out.
Houses can be made of plastic or aluminum, and sometimes wood.
They contain compartments for as few as four and as many as several dozen martin homes.
These are mounted on poles.
Whether gourd or traditional house, you must choose between round openings and crescent shaped openings.
Round openings are easy to cut into gourds, and easy to manufacture, but they are large enough for predator birds to use.
Predator birds will at minimum, harass, or, at worst, eat purple martin babies.
If there are few predator birds, in the area, however, the round openings are fine.
Crescent shaped openings are preferred if starlings are prevalent in the area.
Starlings cannot fit through the smaller openings, and are therefore less likely to harm the purple martins.
With crescent shaped openings, you can also have perches, both on the inside and the outside of the house.
Source...