OSWEGO, Kan. —
A bald eagle, found unresponsive near the Neosho River three miles north of Oswego earlier this week, has died, leaving officials to wonder if it was lead poisoning.
Lead toxicity, more commonly called lead poisoning, has been identified as a concern for several bird species, including bald eagles, according to information from the Iowa Department of Natural Resources.
A resident reported the Oswego eagle to officials with the Department of Kansas Wildlife, Parks & Tourism on Wednesday.
“Nowhere did it show any visible signs of being shot, so we guessed it had ingested some lead someplace,” said Jim Bussone, Crawford County’s game warden with Kansas Wildlife, Parks & Tourism.
Bussone said a department employee picked up the eagle and took it to a Pittsburg veterinarian, Dr. Dick Peterson, for treatment at Langdon Lane Animal Hospital. After Peterson provided initial care, the bird was transferred to the Eagle Valley Raptor Center in Cheney, which specializes in rehabilitation. The bird died Friday morning, Bussone said.
“We’re still investigating the cause; we’re just not sure yet,” he said. “Preliminary testing shows it could possibly have died from lead poisoning.”
During the past 25 years, from 21 to 25 percent of sick or injured eagles treated at the University of Minnesota’s Raptor Center were found to have toxic levels of lead in their blood. Several appeared to be the result of ingested lead slug or bullet fragments.
Although it is a federal regulation that waterfowl hunters use no lead shot, it is optional for hunting deer and other wild game. Although eagles subsist mainly on fish, they are opportunistic and have been observed feeding on fresh deer carcass, pheasants and other wildlife that may harbor lead or lead fragments.
Winter in this area is a time of migration for bald eagles. Bussone said he doesn’t know whether the bird was a local resident or a migrating bird.
“I just don’t want to speculate about that or to the cause of death just yet,” he said.
Bussone said X-rays and blood samples should reveal within a week the exact cause of death. Testing also could show whether it was a local or migratory eagle and its gender.
In the late 20th century, the bald eagle was on the brink of extirpation in the continental U.S. Populations recovered and the species was removed from the federal list of endangered species in 1995 and transferred to the list of threatened species. It was removed from the list of endangered and threatened wildlife in the lower 48 states in 2007.