Sunday, July 17, 2011
Purple martins eager to become our tenants
One of the most prolific wild "pets" in the eastern United States is the purple martin. East of the Rocky Mountains, these large swallows - the biggest in North America - now live exclusively in nest boxes.
People have long been smitten with these charming birds. Native Americans posted hollowed gourds to entice martins centuries ago, and European colonists picked up martin fever and became avian landlords. Witness this 1831 quote from John James Audubon: "Almost every country tavern has a martin box."
Domestication by humans wasn't always part of the purple martin's world. Before then, martins mostly nested in abandoned woodpecker holes high in dead snags.
The beaver probably played a large role in maintaining martin populations. As the furry engineers flooded new ground, causing trees to die, woodpeckers took advantage and created cavities in deadwood. Later, martins appropriated the holes.
As people increasingly enticed martins to nest boxes, the birds gave up their wild ways. By 1900, the transition to human-provided housing was completed.
It's easy to see why we've become beguiled by martins. They ooze charisma and good looks. Males are steely purple, while females are strongly tinged with browns and grays. Both sexes have shallowly forked tails and proportionately massive wings that make them supreme aerialists. Martins feed solely on flying insects, and it takes skill to snatch dragonflies and other speedy fare.
Most purple martin boxes are of the apartment style, with multiple nest holes, or colonies are created by stringing numerous hollow gourds from a beam. These martin villages are fun to watch. Birds constantly come and go, all the while delivering mellifluous gurgling chortles. The residents peek from holes or line up on wires and struts, seemingly gossiping about the goings-on. They remind me of Brooklynites sitting on the stoops of their brownstones, watching the world go by.
Purple martins see a lot of the world. Highly migratory, most of them journey to Brazil and Bolivia for the winter. Some probably travel 10,000 miles round trip each year. The oldest documented martin lived to be almost 14 years old, and that bird probably flew hundreds of thousands of miles in its life.
In late summer, after nesting, martins often form massive roosts. The Ohio Penitentiary, which was on Spring Street near Downtown for 164 years before its demolition in 1998, hosted a martin roost. In the 1960s and '70s, as many as 30,000 martins gathered there - six martins for every inmate. Unlike the jailbirds, the martins were free to go and probably were the envy of any prisoner savvy to their South American destination.
Prime breeding grounds for the purple martin include open spaces and nearby waterways. Some landlords have erected numerous fancy martin high-rises and host small cities of the birds. In May 2007, The Dispatch profiled one of these uber-martinists: Ken Fecker of Waldo, who at the time provided occupancy for 85 pairs of martins.
To learn more about purple martins, including their nesting requirements, visit the Purple Martin Conservation Association's website at http://www.purplemartin.org/.
Naturalist Jim McCormac writes a column for The Dispatch the first and third Sundays of the month. He also writes about nature at jim.mccormac.blogspot.com.