His lifelong interest in purple martins began when 72-year-old Fred Borchert was a boy, visiting his grandfather at a Wisconsin farm.
His grandparents didn't have a television set, so evening entertainment involved sitting on the back porch, watching the birds flit and fly around the houses his grandfather had installed.
"They are just fun to watch," Borchert said, as they dive and glide.
You can now find Borchert watching the birds at his own home in Batavia and at seven houses around the Batavia Riverwalk.
"It is an ideal location, right on the water," Borchert said of the Riverwalk. Plenty of the insects the purple martins like to eat buzz and roam around the Riverwalk, and the birds can drink water from the Fox River.
When he moved to Batavia about 25 years ago, Borchert noticed that the birdhouses near the river were not being taken care of. Grade-school children had raised money to buy the houses. Purple martins used to nest in holes in trees, made by woodpeckers. But now, those east of the Mississippi River rely on man-made housing, he said.
The problem is, starlings and sparrows also like the houses and move in. They are known to peck open martin eggs, roll them out of the nest, build their own nests over the eggs, and in the case of starlings, kill purple martins. The martins are too timid to kick the starlings and sparrows out, he said. Owls, rat snakes and other critters can also steal eggs and fledglings from the martins' nests.
So every other week or so, Borchert lowers the martin houses and looks for the raggedy straw nests the sparrows and starlings make. Martins make their nests out of pine needles, he said; they also build mud half-walls across the entrance to the chamber to try to keep the other birds out. When they leave in August, he cleans and disinfects the houses, then plugs the holes.
The houses are about 22 feet off the ground and are lowered and raised by a pulley system. There are guards around the poles to try to keep squirrels from climbing them, and some of the houses have barriers near the chambers to keep owls from getting to the fledglings.
Purple martins are in the area from April 1 to about Aug. 1, "just long enough to have babies," he said. The rest of their year is spent in Brazil. On their migration south, they join up with other martins, forming groups of several hundred thousand by the time they reach roosts in New Orleans and South Carolina.
There are 96 compartments in the Batavia Riverwalk houses, and usually 45 to 50 pairs of adults set up house. He has seen as many as 190 fledglings a season.
It's not like they arrive April 1 and have babies right away. The birds "seem to take their time getting started with the whole process" of procreating, he said.
Incubation lasts about 15 days, and the birds fledge when they are about 26 days old. Shortly after fledging, they leave for Brazil.
People think that purple martins are good for eating mosquitoes, but that's not true, he said. Martins eat large flying insects, such as dragonflies, wasps, moths and butterflies.
Adults seem to return to the same areas each year, he said. But they have different mates. He recognizes some from year to year.
"They all have personalities," he said, including one male that tries to peck him on the back of his head.
He misses the days before the Internet, when fans of purple martins had to write newsletters and have regional meetings to share their discoveries. The gatherings included Amish families from Indiana. Now, people post their news and videos on sites such as purplemartins.com, the website of The Purple Martin Society NA.
"It's kind of sad as far as I'm concerned," he said.
Batavia birder Ron Gilkerson helps Borchert with the Riverwalk houses, but otherwise, Borchert doesn't know who else would be able to do the job when he's not able.
Borchert has started other colonies around here, including one by the sewage treatment plant in Geneva. He also knows of one west of St. Charles.
"It is a fair amount of work" maintaining the houses, he said. "You need a lot of open space to attract them."