The purple martin is one of few birds who prefer living in colonies rather than in isolated pairs. They provide much enjoyment as they are beautiful, swooping fliers and are friendly around people. In coloring the male is a glossy black or violet, with purple iridescence. The female is light-breasted in contrast to the male.
The martin diet consists almost entirely of insects, making them a desirable bird to attract for natural insect-control. As martins are very active and require a large amount of food, the number of insects they eat in order to get sufficient nourishment can number in the thousands each day.
Purple martins winter in South America, mostly in Brazil. In spring they migrate to North America in order to breed. This occurs in early February in the southern states and in early March in the northern states. The male martin usually arrives well in advance of the females to scout for housing. When visiting a multi-room house, he will go from room to room several times before making up his mind. Martins do not begin their nest building for several weeks after the room selection is over and their mates have settled down.
Martins, members of the swallow family, make their nests out of grass, twigs, straw and mud. (Hint: Provide mud near your martin house – this helps attract a new colony.) Their preferred nesting sites are tree cavities, holes in cliffs and man-made houses. Martin colonies usually return to the same site or house year after year. New colonies are formed when young birds must find nesting sites other than their parents.
Successful martin houses can vary from a simple gourd to a multi-complex apartment. Whatever kind of house you use, it should be up and ready just prior to the martin’s spring arrival. Be aware that putting a house up too early will allow starlings and sparrows to nest in the building before the martin scouts have arrived.
A martin house should be installed 15-20 feet above the ground in an open area away from tall objects from which predators might jump. Martins eat on the wing and therefore must have sufficient space around their house in order to fly freely. Trees near the houses makes this difficult. Martins have been known to abandon housing if a tree is too near, interfering with their flight needs. Martins prefer grassy open areas, preferably with water nearby.
It is important that your martin house be mounted so that it can be lowered each year for cleaning. Nests should be removed each year after the nesting season is over. If needed the house can be sprayed for insects. Also, plug the entrance holes at the end of the season to keep other birds from nesting.
Not everyone is lucky enough to attract martins the first year they put out a house. A perfectly fine well-situated house may not draw any martins for two years. The wait, however, is well worth it.