Research shows contraception could control problem parakeets
GAINESVILLE, Fla. — When monk parakeets began to infiltrate the United States in the 1960s, some feared they would ravage farm crops as they often had in their native South America.
That never happened, but the birds did cause a different kind of problem: They built huge, heavy nests atop power substations and utility equipment, causing power outages, fires and countless headaches for utility companies from Florida to Washington.
But a researcher with the U.S. Department of Agriculture has a solution — he’s going to trim the parakeet population by feeding them contraceptives.
“The birds will still be there, but by reducing their numbers over time, that should go a long way toward solving the problem,” said Michael Avery, a wildlife biologist at the USDA’s National Wildlife Research Center. He outlines the research findings in next month’s Journal of Wildlife Management.
Avery, who holds a courtesy faculty position with UF’s Institute of Food and Agricultural Sciences, said he hopes the contraceptive approach will be more palatable to the public than euthanizing the birds, a technique that had been used after other approaches failed.
“They’re very charismatic little green birds. They brighten people’s day, so people make sure they’re fed,” he said.
The monk parakeet is slightly bigger than a cardinal or robin. It’s bright green with gray markings and a loud squawk. They are unusual in the parakeet family as the only species that builds stick nests, rather than settling into a hole in a tree.
The birds’ nesting habits began to cause problems for power companies in the 1980s, but those problems exploded during the 1990s, most notably after Hurricane Andrew in 1992, Florida Power & Light principal biologist Jim Lindsay said.
“After Hurricane Andrew, our infrastructure was the first thing sticking back up on the horizon,” said Lindsay, based in Juno Beach.
With the company footing the bill, researchers tried every trick they knew to shoo the birds.
They scared them with loud noises. They tried lasers. They hung bird effigies. None of those — which often work with other birds — made a dent, Avery said.
Eventually, researchers learned to catch the birds so that they could be removed from their nests and euthanized, but that was no easy task.
“They’re pretty wary,” Avery said. “If you just come in and pull the nest down, the birds just watch and as soon as the trucks roll away, they start rebuilding.”
In March 2006, Avery and his team went to South Florida, where monk parakeet nest-building was causing the worst problems for Florida Power & Light.
They began installing feeders near utility substations known to have parakeet nests. They initially used a mix of wild bird seed, hulled sunflower seeds and fresh fruit. Once the parakeets were using the feeders, researchers began to fill the feeders with just sunflower seeds. After that proved successful, they mixed the sunflower seeds with the avian contraceptive, DiazaCon.
DiazaCon interferes with the birds’ blood cholesterol levels, needed to produce hormones that govern reproduction.
At 10 sites during the two-year study, researchers found that DiazaCon reduced the number of nestlings 68 percent — from more than four per nest to less than two.
The researchers hope to get the chemical registered with the Environmental Protection Agency as a contraceptive bait for parakeet management, Avery said.
Their next step is to be sure they have a good way to keep “nontarget” birds from eating bait treated with DiazaCon. Researchers began a study in South Florida two weeks ago to see if specially designed feeders will keep other types of birds from getting the contraceptive bait intended for the monk parakeets.
For more information, visit http://www.aphis.usda.gov/wildlife_damage/nwrc/.