It’s a spring season full of chirps at the Point Defiance Marina, where conservation efforts are paying off in the form of vibrant, swooping purple martins—North America’s largest swallows and a beloved sign of the changing season in the South Sound.

Earlier this spring, the conservation team at Point Defiance Zoo & Aquarium expanded the available housing for the birds, adding ten new nesting boxes and six plastic gourds to the Boathouse site. And already, it’s drawing attention from the birds.

“We’ve seen adult birds investigating the new boxes just in the last few days,” said Sam Hain, conservation specialist at Point Defiance Zoo & Aquarium. “We’ve confirmed at least one nesting pair, but volunteers have observed signs suggesting there could be as many as six pairs setting up home here.”

These birds, known for their deep purple and blue plumage, are a migratory marvel. They travel thousands of miles each year from Brazil to return to places like Tacoma, often arriving as early as April and departing by late August. Locals may spot them circling high over the shoreline or perched on weathered pilings at places like Titlow Beach or Chambers Bay.

Point Defiance Zoo has been a key player in keeping these birds around, launching its purple martin community monitoring program in 2013. Trained volunteers help monitor colony activity, track breeding behavior, and report to the Washington Department of Fish and Wildlife (WDFW). The department lists purple martins as a Species of Greatest Conservation Need, meaning active human support is vital for survival.

“Our data tells us that Tacoma is home to a large percentage of the state’s purple martins,” said Hain. “The city could hold as much as 16 percent of Washington’s estimated 600 adult birds, making it a huge bastion for a species that depends on us for nesting habitat.”

Historically, about 34 purple martins nested at Dickman Mill Park, nearly 50 at Titlow Beach, and around 20 at Chambers Bay. There’s also an unmonitored colony on the Hylebos Waterway.

The birds’ reliance on human-made housing stems from habitat loss dating back to the 1930s, when forestry operations eliminated many standing dead trees that once provided natural nesting cavities. The introduction of invasive birds like house sparrows and starlings also made competition for those few remaining spots fierce.

Since then, conservationists have provided nesting boxes and gourds that mimic the cavities the birds would naturally use. These structures are placed close together to suit the birds’ preference for communal living, though not too close, as squabbles among neighbors are common.

The new gourds and boxes at the Marina are another step in supporting the local population while still encouraging martins to seek out natural cavities as the species slowly rebounds. The team is focused on confirming pairings, observing breeding activity, and sharing findings with its conservation partners.

Want to be part of this story? You can. The Point Defiance community monitoring program will be looking for dedicated volunteers in 2026 to help track the lives of these captivating birds. Volunteers are trained in identification, data collection, and how to recognize signs of nesting success.

Visit the zoo’s community science page to learn about all the ways the zoo is contributing to important conservation.