Wildlife officials in Utah are trying to determine what is causing the state's bald eagle population to die in great numbers.
Since the beginning of this month 16 bald eagles have died with no explanation, state wildlife officials said Tuesday.
Blood samples taken form the dead birds was sent to a lab in Madison, Wis., in order to conduct toxicology screenings, revealed DaLyn Erickson-Marthaler, executive director of the Wildlife Rehabilitation Center of Northern Utah.
"I couldn't even begin (to speculate) what's wrong with them yet," Erickson-Marthaler told NBC. "If we start focusing on one thing right now, we could miss something else entirely."
One theory that has been floated is the possibility that the birds are being poisoned, either intentionally or accidentally, but officials say that seem unlikely as the dead birds have been found in several counties and not just from one location.
"This is hard to treat because we don't know exactly what it is," said Leslie McFarlane, wildlife disease coordinator for the Utah Division of Wildlife Resources. McFarlane added that the deaths seem to be just affecting the local bald eagle population.
Before they die, the bald eagles are found to have weakness in their legs, which turns into paralysis of one leg and then the other, said Erickson-Marthaler. The birds also experience head tremors and then seizures. They typically die three or four days later.
The latest bird taken in on Monday from Davis County was still in "pretty good shape," although he had difficulty standing, Erickson-Marthaler said.
Utah hiker Taylor Schulte told local media that he found a bald eagle recently while on a ski trail and was able to capturing the bird on video before bringing him to the attention of wildlife officials.
"There's no doubt that that bird wouldn't have even had a chance if we weren't there," Schulte told NBC. "With the cold temperatures and the predators in the area, if we hadn't been there … there's no way it would be alive right now. It definitely needed help."