Six bald eagles have died and six more are in veterinary care after being poisoned on Vancouver Island.

Volunteers with the local Raptor Rescue Society found two of the birds on Wednesday and 10 more on Saturday.

The surviving animals are responding to treatment, but the type of poison and its source are unknown, the society said.

“The assumption is they’ve probably all fed off of the same carcass,” Robyn Radcliffe from The Raptor Rescue Society told CTV Vancouver.

“Euthanizing an animal and then dumping it illegally or accidently disposing of it improperly, we don’t know.”

Volunteers are scouring the area where the eagles were previously found in hopes of finding any more ailing birds.

“We were very happy that we were able to rescue and help six of them. I just wish we could’ve helped more,” Radcliffe said.

A veterinarian caring for the eagles says he’s thankful to have saved six, but he’s frustrated that the deaths were likely caused by humans.

“The ones found alive were barely alive,” said Dr. Ken Langelier with the VCA Canada Island Animal Hospital. “And the fact that the other six, if they could’ve been found in time, could’ve been saved if the poison had been removed is always disturbing.”

In a Facebook post, The Raptor Rescue Society appealed for help to find any more poisoned eagles.

“Anyone in the Cowichan Valley is asked to look for sleepy, 'drunken', or dead bald eagles.”