Purple Martins

Local Streams

Nest box programs have helped to stabilize the declining purple martin populations, but require monitoring and maintenance to ensure that purple martins return year after year.

The Purple Martins Are Here!

Interested in monitoring these amazing aerial acrobats? Join the East Bay Purple Martin Monitoring Team!

Mid to late April marks the return of the largest swallow in North America, the purple martin. Migrating to the Pacific Northwest and up into Canada from as far away as the Amazon River and southern Brazil, the martins return to their summer homesites, delighting us with their aerial acrobatics.

The martin has a body length of about 17-20 centimeters (6.7-7.8 inches). Adult males are uniformly iridescent purple to blue-black in color. Females and immature birds are colored similarly, but slightly lighter on the chest. Sometimes the female will have a faint collar around her neck. The tails of purple martins are slightly forked.

Purple martins once nested exclusively in large tree cavities along rivers and coastal shorelines, feeding on flying insects. Due to increased development along our shorelines, most purple martins now nest in man-made nest boxes like the ones monitored by Stream Team volunteers at East Bay.

Purple martins form monogamous pairs through the nesting season, and the pair prefers to nest in boxes over water. Within the nest box, both members of the pair build a nest cup of leaves, grass and twigs, with mud at the base of the entrance hole. The female incubates four to five eggs for 15 to 18 days, possibly with some incubation by the male. Both members of the pair feed the young. The young leave the nest at 28 to 29 days, and the parents continue to feed them for five to seven more days. In late summer, the purple martins gather with other purple martin colonies and begin the long migration back to South America.

Nest box programs have helped to stabilize the declining purple martin populations, but require monitoring and maintenance to ensure that purple martins return year after year. Through the dedication of volunteers monitoring this species and the valuable data they supply, the population of purple martins in Washington is slowly increasing.

Today there are 26 purple martin nest boxes located in East Bay (Olympia) that have been erected and monitored by Stream Team volunteers. Between late April, when the martins arrive, until early September, when they migrate south, volunteers have the opportunity to observe the martins as they build their nests and fledge their young.

Stream Team volunteers help monitor the nest boxes weekly for nesting activity and fledgling success. Once the martins have left for the season, volunteers also help clean the nest boxes, readying them once again for occupation in the spring. Monitoring is easy and takes only one hour per week. If you are interested in observing these amazing swallows, contact Michelle Stevie at mstevie@ci.olympia.wa.us or 360-753-8336 for more information or to sign-up.

Things You Can Do To Help Purple Martins

  • Retain dead and dying trees (snags) on the landscape (especially near saltwater and wetland sites)
  • Avoid using pesticides