A wildlife caretaker is trying to figure out what's paralyzing ravens in B.C.'s Peace Region.

Leona Green says more than 30 paralyzed ravens have been dropped off at her wildlife rehabilitation centre near Dawson Creek since May. 

Green says she has never seen anything like it in her 30 years of working with animals.

"Their legs were paralyzed, and then they actually atrophied. They almost looked like they were mummified," she said.

Despite Green's efforts to rehabilitate the birds, they all died.

"Then this kind of mushroomed. I kept hearing more and more about it, and more dead birds," she said. "What's upsetting about it is the fact that we don't know what it is. Is it going to affect other birds, or even animals? We don't know."

Green says she has sent the bird carcasses to a lab in Abbotsford in the hopes of solving the mystery.

The province's Fish and Wildlife Branch would not comment on the deaths until the tests are completed, but a spokesperson said they don't believe there is a risk to human health.

With files from CBC's Marissa Harvey