Down at the Point Defiance Marina in Tacoma, Wash., large swallows are diving from up high in the sky to down under the boardwalk and into nesting boxes, where they’re feeding their newly fledged chicks.
“It's one of the exciting parts of my morning, is seeing the reports come in and see which boxes have had babies and all the notes from our volunteers,” said Sam Hain, a conservation specialist for the Point Defiance Zoo and Aquarium.
As part of Tacoma’s parks department, the zoo maintains nesting boxes at the marina and other sites along the Puget Sound. About 40 volunteers go out multiple times a week to the sites to observe the birds and report back to the zoo.
The work is part of an effort to restore habitat for the birds, who are cavity nesters that rely on manmade structures for their summer homes in the Pacific Northwest.
Sightings of the chicks and adult birds feeding behavior indicate that the effort is working.
“I would say without the boxes, the birds wouldn't be having as much of a recovery in the region,” said Zachary Hawn, conservation program coordinator for the zoo. “Based on behavior, we know the colony is successfully having chicks.”
I would say without the boxes, the birds wouldn't be having as much of a recovery in the region.Zachary Hawn
Hawn said since people have been putting up more nesting sites for the birds, and maintaining them, there has been an increase of purple martins in the South Sound.
The Washington State Department of Ecology is preparing to do a survey of the birds around the state to better understand how beneficial these nesting boxes are to the species.
Right now, the adult purple martins are foraging for large insects to feed their chicks. To spot them, look for dark bluish, purple-colored big swallows with blunt tails, flying high up in the sky. Purple martins are bigger and fly higher than other swallows and catch large insects like dragonflies and butterflies to feed their babies.
“As the babies get larger and need to eat more and more, [the parents] have to return more and more often,” Hain said. “Especially with some boxes, you might have four or five babies in one box, so the parents are making constant trips to feed them as they're growing.”
They’ll do this until the baby birds are ready, and big enough, to migrate this fall — all the way to South America.
“It's very impressive for the babies that are born this year. It's kind of the first thing they do once they're out of the nest is, ‘All right, now fly to Brazil,’” Hain remarked.
