Dec 25, 2013 03:17 PM EST By Jaleesa Baulkman, UniversityHerald Reporter

Utah state wildlife officials announced that at least 16 bald eagles have died in Utah from unknown causes since the beginning of the month.

The Utah Division of Wildlife Resources believe a mysterious illness is killing off the government-protected birds and are scrambling to diagnose it before it spreads, according to NBC News.

"It's frustrating and heart breaking," Leslie McFarlane, wildlife disease coordinator at the Division of Wildlife Resources, told KSL-TV in an interview earlier this week. "It's really hard because you want to be able to do something right now and we just can't."

In an interview with KSL-TV, DaLyn Erickson-Marthaler, executive director of the Wildlife Rehabilitation Center of Northern Utah, said the bald eagles were experiencing the same symptoms. She said they showed signs of body tremors, they have had seizures, they appeared to be paralyzed and they had weakness in their feet and in their legs.

A lab in Madison, Wis., is currently conducting blood work and toxicology on the carcasses, Erickson-Marthaler, told NBC News. The results may not be available for a couple of weeks.

 "I couldn't even begin [to speculate] what's wrong with them yet," Erickson-Marthaler told NBC News. "If we start focusing on one thing right now, we could miss something else entirely."

Earlier this month, wildlife officials were alarmed when a number of unexplained bald eagle deaths in Utah occured after hundreds of the birds migrated to the "wintering grounds in the central Rocky Mountains," Reuters reported.

The bald eagle is the U.S. national symbol. They were recently removed from the federal threatened and endangered list after their numbers came back from near-extinction.

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