Seven elk have died in the Red Desert area in south-central Wyoming over the winter months and common tumbleweed lichen seems to be the culprit.

Tumbleweed shield lichen is abundant in the state of Wyoming and has also been implicated in the poisoning of domestic sheep and cattle in the past. This lichen, when digested by animals such as elk, causes long-term paralysis leading the animals to eventually succumb to starvation, dehydration or predation.

“It is unclear why elk eat the lichen,” Mark Zornes, the Wyoming Game and Fish wildlife supervisor told The Casper Star Tribune. “While it is a very unfortunate event, we really can’t prevent the elk from eating the lichen. These lichen toxicity incidents are sporadic and do not impact the overall elk population.”

Game Wardens have reported an abundance of the lichen in the vicinity of the deceased elk and also reported red urine stains in the soil, which is often a tell-tale sign the lichen was ingested. Game warden Andy Roosa stated in a release that more than 500 elk have died between the years of 2004-2008 from lichen toxicosis in the Red Rim area.

“While the number of affected elk has not been anywhere near that high this year, Green River Region and Lander Region personnel have responded to a number of reports of paralyzed elk in the Red Desert this winter,” Roosa added.

H/T: The Casper Star Tribune