Making Room for Purple Martins on Public Property

As bird populations continue to decline, volunteers are scouting new real estate for purple martins in parks, schools and other public settings

By Heather Valey and Delaney McPherson
Wildlife Photos
Mar 28, 2024

A once-injured male purple martin found by volunteers now resides at a wildlife rescue in Houston, Texas. (Photo by Heather Valey.)

FOR PURPLE MARTINS and the humans who admire them, one solution to habitat loss may be in plain view: public land.

While numbers vary, some estimates put the population decline of the North American songbird, which winters in South America, at about 25 percent from 1966 to 2021. To help offset that prolonged drop, a collection of people—colloquially known as purple martin “landlords”—have long installed substitute housing in their yards or gardens. These nesting sites—which look like either miniature “Star Wars” apartments or cell towers, depending on whom you ask—mimic the martins’ natural choices for homes: the holes in trees or crevices between rocks. As secondary cavity nesters, the birds do not build their own nests.

Now, though, as the birds’ numbers continue to dwindle, some dedicated martin lovers have staked out new territory for pioneering colonies. Two of those leading the charge are Julia and Andy Balinsky, married martin landlords in Austin, Texas, who manage a pair of colonies on municipal property: one at a biosolids treatment plant and another at a city park.

Finding those locations and getting the colonies started, they say, was the easy part. “You don’t just sit back and watch. It’s a lot of work,” says Julia, who has been a purple martin landlord for more than 20 years. “Ideally, we try to visit the colonies every five days from April to mid-June.”

The Balinskys check nests frequently to ensure martin fledglings are healthy and that no invaders—often invasive European starlings or house sparrows—have encroached. In times of drought or bad weather, landlords may provide supplemental water or food, such as crickets or mealworms. The Balinskys also volunteer with their local Audubon chapter, leading seminars on taking care of the martins and mentoring new landlords. They say all the effort pays off in the last few weeks before the fall migration south, when hundreds of thousands of martins gather together in one spot.

“The impressiveness of the massive roost of swirling birds, and knowing you had a part in that, is a big moment,” Andy says. “You tally up the spreadsheets [of successfully hatched and fledged martins], and it feels good to know that those birds wouldn’t be in the sky without us.”

Read more about photographer Heather Valeyand see more of her purple martin photos below.

IN THE GOURD ROOM

Each nesting box, or “gourd,” typically houses four to six fledglings and both parents (above), who will provide for the young until the offspring are ready to leave the nest. Because purple martins are colonial nesters, landlords usually start with at least six to 12 gourds, adding more as the colony grows.
These efforts to build colonies on public land—such as at the Austin Water Center for Environmental Research at Hornsby Bend (above)—have helped build community among the birds and volunteers, who tend to be devoted to the cause. “People who have colonies usually had some exposure early on to purple martins that captivated them,” says Joe Siegrist, president and CEO of the Purple Martin Conservation Association (PMCA).
While martin landlords—including Laurie Evans of Austin (above)—have long installed colonies in their yards, continued purple martin declines have led advocates to establish colonies on public property.
THE NEST OF THE STORY

Landlords perform nest checks, tracking the number of eggs and the progression of fledgling growth, monitoring for illness and, if necessary, removing predators or invasive species that attempt to take over nests, killing nestlings and destroying eggs in the process (above). Landlords then share the data they collect with their local Audubon, PMCA or other environmental groups for further research.
Purple martins usually lay four to six eggs per clutch, and the eggs incubate about 15 days. Once hatched, the martins grow rapidly (above: a 10-day-old-nestling and a day-old hatchling) and will be ready to begin living on their own just over a month later.
SUMMER SOIREE

In late summer, purple martins leave their colonies and congregate en masse in preparation for their migration back to South America. Travis Audubon hosts viewing parties at one such roost site, Capital Plaza in Austin (top), where the public can watch as hundreds of thousands of martins take to the sky each evening at dusk. Roosts last about three months, during which smaller groups of birds break off and begin their migrations. By mid-September in Austin, nearly all martins are on their way south, giving the landlords a few months off before their work begins again in the spring.