Purple Martin

Progne subis
PROFILE Martin 520x289

 "Almost every country tavern has a martin box on the upper part of its sign-board; and I have observed that the handsomer the box, the better does the inn generally prove to be."
-John James Audubon, 1831 

There is something about the Purple Martin that speaks to humans, somehow endears them to us in a way that other backyard birds can’t quite muster. Perhaps it’s their large, glittering opal eyes, or their liquid, almost conversational burbling to one another; or could it be their obvious gregariousness, the fact that they dwell in colonies like we do? Maybe it’s their tolerance of—and, at times, reliance upon—our proximity, the trappings of our altered environment. Whatever the reason, there exists a sort of mutual dependency between the species. It is difficult to say which came first: the trusting martin, or the solicitous, accommodating human.

From time immemorial Purple Martins have commanded the attention of humans wherever the twain meet. "Twirl on, you and your satin blue/Be water birds, be air birds/Be these purple tumblers you are," wrote American poet Carl Sandburg in 1920, admiring the martins in Chicago. High-flying, chatty flocks of these swallows return to much of North America every summer from their wintering grounds in Central and South America. It is at these northerly latitudes and nowhere else that martins breed and raise young, feeding chicks with insects captured in acrobatic sorties hundreds of feet overhead, typically above the affairs of other swallow species. 

Native Americans in the Southeast found that martins would readily nest in gourds hung from trees; whether they saw these birds as useful insect-devouring comptrollers or simply enchanting seasonal charges is unclear. But they set in motion a conservation ethic that continues to this day, and in places amounts to outright stewardship.

Purple Martins are cavity-nesting birds. In the West, they’ll use everything from burned-out conifer trunks and decaying snags to old woodpecker holes in saguaro cactus, constructing rudimentary nests of twigs, grass and mud within. In the East, however, such naturally-occurring recesses are increasingly hard to come by. Cities and suburbs have paved over much of the decadent hardwood forests that supplied those cavities, and any that remain are often swooped upon by non-native nesters such as European Starlings and House Sparrows—birds that have little compunction about evicting touchy martins.

This is where dedicated backyard birders step in, folks that go beyond setting up a couple feeders near the porch, a birdbath on the lawn, maybe a store-bought birdhouse nailed to a tree. These are people that build summer homes of sometimes amazing complexity and craftsmanship—think miniature apartment complexes, high-rise condominiums catered to the doll-sized jet set—for the waves of breeding martins that arrive each year. They call themselves “landlords” and their nest structures "property", and it’s no small thanks to them that populations of Purple Martin are thriving—especially in the East, where the species is almost entirely dependent on human-made houses for nesting.

These landlords debate merits and demerits of their various properties in online forums; they bandy about terms like “scouts” (the first birds to return each spring), “behavioral pattern shifting” (referring to martins’ habituation to the human landscape), and “starling-resistant entrance holes”, or SREHs, installed to safeguard martin houses against avian repossession. There is a bit of the martinet that creeps into some of these discussions. Rival camps espouse certain “standardized” property layouts and excoriate others; rival landlords sometimes poach from neighboring colonies by providing superior housing or better amenities, all the while claiming that they’re “just doing what’s best for the birds.” Which, strictly speaking, should be foremost in the interest of everyone involved. But the Purple Martin realty market can be a shark tank, and only the aggressive, proactive landlords secure quality tenants—ones that return punctually each year, sometimes bringing referrals—while keeping out the squatting riffraff of sparrows and starlings.

At Siletz Bay Refuge are a number of nest boxes built and installed by staff and volunteers for the benefit of cavity-nesting birds, be they Purple Martins, Tree or Violet-green Swallows, Wood Ducks or chickadees. Look for these boxes along the banks of tidal sloughs or atop breached earthen dikes. In the spring and summer, watch closely for active nests—and of course keep eyes and ears open for Purple Martins banking, circling and burbling high above the estuary.

Read about volunteer efforts to bring breeding martins to Nestucca Bay National Wildlife Refuge.

Facts About Purple Martin

-Largest North American swallow, among the largest in the world

-A secondary-cavity nester, dependent on previously excavated recesses (or artificial structures) to breed

-Migrates from North American breeding grounds to Mexico, Central America and upper South America in winter

-Hunts insects at higher altitude than other swallows, usually 150-300 feet up