Fond du Lac County — An invasive species wintering on local farms is causing problems for livestock, and a farmer's livelihood.
A starling eradication program in Fond du Lac County began in December 2016 and will run through March, said Charles Lovell, district supervisor for the USDA Wildlife Services in Waupun. The program uses a pesticide application to eliminate the pesky birds, which can number into the thousands when they choose to move in on a large livestock operation, he said.
Described as a gregarious, old word songbird, starlings were brought to America by European settlers, who thought the new country should contain every species of bird found in Shakespeare’s works, Lovell said. Other invasive birds include pigeons and house sparrows.
The program has been in existence for more than a decade, and particularly benefits dairy farmers, who this time of year can be invaded by flocks of the black birds, Lovell said.
“In winter they like to move indoors, into barns where there is an easy food source, warmth and protection,” Lovell said. “They defecate all over the cattle, the feed and water, and farmers often see a reduction in milk production.”
Some birds who carry disease also pose a potential, fatal threat to livestock, he said.
Pesticide-laced bird food is scattered around the area, but away from livestock feed. The starlings usually die within a day or two, and the poison is metabolized by the bird, Lovell said, meaning none of it remains inside the carcass.
The state-wide eradication program can also include cowbirds and blackbirds.
Lovell said it is up to the farmer to contact wildlife services to ask for help, and a small fee is charged.
On average the department treats approximately 30 farms a year, and after treatment, the farmer typically reports a 90 to 95 percent reduction in what they perceive as a feathered nuisance.
Starlings are not protected by the Migratory Bird Treaty Act. They were first released in Central Park, New York from 1890 to 1891 and were first detected in Milwaukee in 1923. By 1936 they had spread throughout the state, according to the Wisconsin Department of Natural Resources.