WALLA WALLA — Shooting them didn’t do it. Nor did trapping.
But nowadays the notorious Drumheller pigeon gang is down to a couple dozen birds and could one day be completely eradicated — thanks to feed laced with a birth-controlling chemical.
“This technique has existed for about as long as I did this work,” said Z Pest Control owner and operator Paul Zimmerman, who is in charge of giving the contraceptive feed to downtown flocks once a day.
The first use of nicarbazin, which is marketed as OvoControl, was approved in 2005 by the Environmental Protection Agency but not for pigeons. Instead, OvoControl was tested and proven successful on controlling resident Canada geese in parks, golf courses and other test sites across the country.
The product, made by California-based Innolytics, is a bait that interferes with the hatchability of eggs, according to ovocontol.com.
By 2008, the EPA had approved OvoControl for pigeon control, and it was being used in cities across the nation, including Walla Walla.
The numbers show that the contraceptive program works and costs less than the old-fashioned ways of trapping and shooting.
Before using OvoControl, pigeon control in Walla Walla cost $9,000 in 2006.
Zimmerman said as the population drops, so do his costs, which are now down to about $3,600 for the year to control three flocks of pigeons — the Drumhellers, the Mill Creek gang and the Odd Fellows.
Zimmerman noted that he still has to shoot the Mill Creek pigeons with pellets on occasion because state officials won’t allow OvoControl to be used around the creek. And the combined shooting and contraceptives are working on that flock.
At one time, Zimmerman counted as many as 160 pigeons cooped up under the tunnel of the downtown channel. That flock is now down to fewer than 50.
Though the flock is now low in numbers, its capacity to breed is still a threat, especially when you consider that pigeons can double their population every two months.
So left to their lovebird lonesome selves, the Mill Creek flock would leave the looks of downtown dropping.
“They impact the quality of life in the downtown corridor,” Zimmerman said. “You are looking at aesthetics. When everything is covered in pigeon droppings, it just is not a pleasant place to be.”
So about every two weeks Zimmerman refills the automatic feeders that are set up on several rooftops and in the channel. The feeders are set to go off at the same time every day.
As for the possibility that other birds will eat the OvoControl, that is unlikely because pigeons — feathered hogs that they are — feed in a sharklike frenzy when it comes to their food.
“They mob the source, they won’t let other birds near it,” Zimmerman said.
Using contraception to control animal populations is not only for the birds.
The Blue Mountain Humane Society has a trap-neuter-and-release program that has lowered the number of feral cats in Walla Walla.
The Humane Society of the United States also supports immunocontraception, stating it is the most humane method to control wildlife and has been proven successful to control white-tailed deer in New York, bison on the Santa Catalina Islands off California and elephants in South Africa.
Later this month, Zimmerman said he will start a new program geared at reducing the sparrow population at Washington State Penitentiary in Walla Walla.
Apparently some sparrows have broken in and made permanent residences in the larger facilities at the prison. Officials would like them captured live and released without harm, Zimmerman said.
Alfred Diaz can be reached at email@example.com or 526-8325.