A welcome mat is being laid out along Ruston Way for purple martins.

The dark purple and blue birds – North America’s largest swallows – have historically had a thriving colony nest along Tacoma’s shoreline in the spring.

In fall 2024, many of the boxes and gourds the birds called home had to be taken down because they were affixed to decrepit wooden pilings in front of Dickman Mill Park that were being removed by the state.

This month, staff from Point Defiance Zoo & Aquarium relocated 16 nest boxes to a berm south of Chinese Reconciliation Park and are starting to rebuild the purple martin colony there.

“We’re hoping the offer of waterfront homes will lure some of the experienced birds back to Ruston Way and they’ll set up shop there,” said zoo conservation coordinator Zach Hawn.

Purple martins are native birds that migrate back to Washington and other areas of the West Coast, usually arriving from Brazil in early April and departing by late August.

The birds, beloved for their pest control and throaty chirps known as the Dawn Song, are an important species that restore balance to the ecosystem.

Washington Department of Fish and Wildlife (WDFW) lists purple martins as a Species of Greatest Conservation Need due to their low population in the state and vulnerable nesting sites. The designation means human intervention is necessary for the birds to succeed.

WDFW is planning a statewide comprehensive survey this year to gain a better idea of the purple martin population. Conservative estimates are that there are 600 adult purple martins in Washington, and that Tacoma could have as much as 16% of the state’s population.

To help monitor the bird’s population, Point Defiance Zoo & Aquarium launched a community monitoring program in 2013. Volunteers are trained to collect data about the local purple martins and their breeding behaviors, which includes carrying food into the nests or flying fecal sacks out.

The main purple martin colonies in and near Tacoma can be seen at Titlow Beach, the Point Defiance Boathouse, Chambers Bay and hopefully south of Chinese Reconciliation Park soon.

It’s unknown how many birds were displaced in 2024 when the Dickman Mill pilings were removed, but community monitors counted 34 adult birds there.

“We saw a rise in population at other purple martin colonies in the area last year, so we know the birds are nearby,” said Sam Hain, conservation specialist at Point Defiance Zoo & Aquarium. “This is an important species right here in our backyard that needs help and we will continue to support them any way we can.”

To help accommodate the displaced birds, zoo staff last year expanded housing for the birds by placing an additional 16 nest boxes at the Boathouse.

Purple martins nest as a colony, which is why boxes and gourds are grouped together. The birds like to be close but not too close.

The purple martins’ population started to decline in the Pacific Northwest in the 1930s when forestry operations removed large amounts of timber that housed natural cavities traditionally used by the birds as nests. Around the same time, non-native birds such as house sparrows and starlings were introduced to the area and competed with purple martins for resources and nesting habitat.

With a loss of habitat, purple martin numbers dropped so low that local scientists and bird enthusiasts began building homes for the birds in an effort to recover the species. That helped the western populations rebound but also made them reliant on human-made housing.

To learn how to volunteer with the community monitoring program, visit Community Science | Volunteer | Point Defiance Zoo. You can share your observation of purple martins with WDFW using the wildlife reporting form.