Bird migration is perhaps one of nature's greatest feats, easily observed each spring as waves of species arrive from warmer climates each week. I always enjoy watching the spring progression, observing our bird feeders and the woodlands and natural areas around our house for the first signs of each particular bird's arrival.
For eight years, Champaign resident and Master Naturalist Paul Wilson has been especially interested in the return of one particular bird species. Wilson is an avid birder, closely watching the bird utopia that he and his wife have created in their backyard for arrival of new species each week of spring. However, Wilson travels to a nearby Carle Clinic location to carefully observe the arrival of one species of particular interest each spring, the purple martin.
"I grew up with a martin house on our property in Oklahoma," recalled Wilson. "I loved the fact they really are 'people birds' having a long history with humans on this continent."
Prior to European settlement, some Native American tribes reportedly hung up hollowed-out gourds for nesting purple martins. Later, Europeans caught on, adorning structures with various forms of martin housing. Pioneering ornithologist John James Audobon noted the significance of martin houses in his travels during the 1800s with this account from 1831: "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."
Today, almost all purple martins east of the Rockies nest exclusively in human-made birdhouses, creating their close relationship with our species. Western populations use the traditional nesting structure, seeking out natural cavities in trees to raise their young. They are colonial with sometimes dozens of martins nesting in the same spot each year.
Wilson, now a retired physician from Carle, led the charge to establish a martin house at the Carle Clinic location near Mattis and Windsor avenues in Champaign back in 2011. He petitioned his fellow employees to raise some funds for materials and constructed two large martin houses near a pond at the east side of his clinic. Over the years, it has gained attention from patients and employees alike as the human-friendly birds make their acrobatic and entertaining dives and twists to eat insects or get a drink from the pond.
"Birds are just one of those things in nature that everybody likes," Wilson said. "They are fun to watch and they do eat insects."
Although Wilson does admit that the insect-eating benefits to humans may be a bit overstated for martins in the past. They do forage almost entirely from the air, even drinking water on the fly, as they feed exclusively on a wide variety of flying insects.
Martins typically forage higher in the air than other birds, making the insects they eat generally less pesky to humans. However, historical accounts have made extravagant claims such as eating "2,000 mosquitoes a day" with little basis in science to corroborate and research identifying a diverse diet of wasps, winged ants, some bees, flies, beetles, moths, butterflies and dragonflies.
Each spring, Wilson diligently watches for the return of his beloved martins. He noted that they typically arrive in Champaign County around April 1. The Purple Martin Conservation Association has a wonderful website for tracking migration.
According to data reported on its site, Wilson's martin colony is often one of the first to arrive in Champaign County each year. It has grown from an initial population of four pairs in 2011 to over a dozen breeding pairs today.
When asked what his biggest challenge has been, Wilson replied, "Weather has been our biggest challenge; the wind can really push over the tall poles used for martin houses."
In recent years, Wilson moved the houses and installed new poles with about 5 or 6 feet of below-ground cement and they seem to be holding up well. He usually checks the colony once or twice a week by cranking the martin house down its pole on a pulley system. The nests do require some maintenance to prevent invasion from introduced species such as European starlings and house sparrows, but it's a labor of love for Wilson.
"It's a fun, satisfying hobby when you see the young martins fledge and begin to forage on their own," Wilson said.
Each year he bids them adieu in late summer as they begin the long trek back to overwintering grounds in South America.
The purple martin certainly has a unique history and relationship with human populations. Although our species has driven habitat loss on this continent, seriously threatening martin populations, we have artificially supported their kind by providing nesting structures for eastern populations. It's an interesting story of success with captivating birds that truly are "people birds."
Ryan Pankau is a horticulture educator with the UI Extension, serving Champaign, Ford, Iroquois and Vermilion counties.