The Purple Martin is our largest and one of the friendliest of the swallow family. Hundreds of years ago the Plains Indians hung gourds around their encampments to attract these birds. One of the main reasons for having these birds nearby was they would become very excited when strangers approached. As for mosquito control its not thought to have been the main reason. The Martins habit of foraging higher in the air and needing larger insects to supply their needs seems to eliminate the mosquito as a viable major food source. Ornithologists claim in stomach examinations over many years that the mosquito has been found in only a fraction of the birds, and in very small or almost accidental amounts. However, it still remains one of the most sought after birds we would like to attract to our yards.
The Purple Martin needs a large, unobstructed open area to satisfy their needs around the nesting houses. They are large and fly swiftly so they need this open area to maneuver. When we consider the type of housing Martins prefer it appears to vary a great deal. Some prefer gourds, others wooden houses, but the advanced use of aluminum housing seems to work just fine. The gourd offers a larger and safer type of home than others. The larger area assures more eggs to be laid and a better chance of survival for the chicks. The free swinging gourds, either plastic or natural, seem to do a better job repelling raptors such as owls and hawks. The cavities of houses mounted on posts and having a porch are much more accessible to aerial predators. The lack of a porch also assures that the young Martins will not venture out too soon, again becoming easy pickings for a marauding passerby. It also prevents larger hatchlings from an adjoining nest to steal food or accidentally trample their smaller neighbors. Another advantage of swinging gourds is reports that Starlings and House Sparrows (the greatest competitor for any of our native cavity nesting birds) are less of a problem.
Dr James Hill, founder of the Purple Martin Conservation Association, says that in a study of more than 2000 nests, the larger gourds turn out more chicks per unit than any other type. Talking to several very successful Martin landlords they also agree. These folks have removed the walls in the traditional 6 X 6 spaces, thus doubling the nesting area, and have reported higher success rates.
A very useful tool for attracting Purple Martins is the “Dawn Song”. On cassette or CD, it plays the excited call of a male Martin attempting to attract a female to a new colony site. The taped call can be heard at great distances by other Martins, who at least come and inspect the area of the song source. If you are contemplating becoming a Martin landlord, or have tried unsuccessfully to begin a colony, the “Dawn Song” might help. Then there are many folks who have attracted Martins over previous years and have lost them. Oftentimes it is simply due to trees having grown taller and restricted the free movement that their Purple Martins once had.