Purple Martin Conservation Project

Purple Martins, our largest swallow species, have experienced a significant decline in their population over the last 100 years, with over a 25% drop in the last 50 years alone. While habitat loss and food shortages have caused some of the decline, the major reason for the population loss is competition for nesting cavities from two invasive bird species, European Starlings and House Sparrows.

Purple Martins are colony nesters and also secondary cavity nesters, meaning that they cannot excavate their own holes.  Before relying on human-provided housing, Purple Martins historically nested in natural cavities, such as abandoned woodpecker holes, hollow trees, and crevices in cliffs or rock formations. They often selected dead trees (snags) in open areas, near water, or along forest edges for nesting.  Thousands of years ago, Native Americans began the tradition of providing hollowed-out gourds for the birds, leading to a “behavioral tradition shift” where eastern populations became completely dependent on human-provided housing of multi-compartment accomodation and gourds. They like to nest in large groups and have now evolved to feel most comfortable around people.