As the largest member of the swallow family, Purple Martins measure about 7 1/2" to 8" in length. They are a rather stout swallow, with pointed wings and a forked tail. Purple Martins have a similar flight pattern, but with longer glides than other more common swallows. The adult male has a shiny steel-blue plumage, while the adult female has a patchy lighter-colored breast. Males and females that hatched the previous year, and are in their first breeding season, have a similar appearance to the adult female.
Purple Martins feed solely on flying insects including dragonflies, houseflies, moths, beetles and damselflies. Purple Martins are extrememly agile fliers, allowing them to capture their insect prey in mid-flight. They also drink and bathe while flying over open water.
The main predators of Purple Martins are hawks and owls. They target recent fledglings in flight and also can pull nestlings out of nesting compartments that are too shallow (6" x 6" or smaller).
In Minnesota, the first Purple Martins, which arrive in early April, are the oldest adult males and females, with the youngest birds arriving several weeks later. The males first defend their territory and then attempt to attract a female to their desired nesting cavity. Purple Martins lay an average of four to six eggs in a nest made with coarse materials and mud, and lined with green leaves. Incubation lasts 15 days on average. The young birds fledge approximately 28 days after hatching. The nesting season lasts until mid-August when the final nestlings fledge. During the winter months, Purple Martins migrate to the insect-rich tropcs of South America. |
