CHRIS MERRILL Star-Tribune environment reporter | Posted: Saturday, March 8, 2008 12:00 am
Elk have suffered paralysis and died again in the Red Rim area of southern Wyoming, but scientists haven't yet seen any hints that a catastrophic kill is looming like the one they witnessed in 2004.
Three elk died this week in the Red Rim area southwest of Rawlins, and all three were possibly poisoned from eating a form of lichen that causes them to lose the use of their legs, a Wyoming Game and Fish Department biologist said Friday.
Four years ago, 300 animals from an 800-elk herd died after eating lichen in the same area.
It was later determined that a constituent in the lichen can be toxic to the elk, even though antelope have been known for decades to eat the same fare with no ill effect.
Most of the 300 elk that died in 2004 simply lay down and never got up again, according to Greg Hiatt, a wildlife biologist with the Game and Fish Department.
Hiatt witnessed two elk exhibiting the same symptoms Thursday, he said - both were alert, but unable to stand up even as Game and Fish staff drew close attempting to rouse them. There was another elk already dead in the vicinity.
Game and Fish euthanized and collected the two that were unable to walk and took them to the Wyoming State Veterinary Laboratory, where state vets performed post-mortem exams Thursday night.
Hiatt said the necropsies did turn up lichen in the stomach of one of the animals, but not in the other. Kim Olsen, the regional game warden, observed one week earlier that the entire herd had been eating lichen. It's apparent when they do because the lichen in the Red Rim area changes the color of the elk's urine to a pinkish and finally reddish hue after continued consumption.
Hiatt said Game and Fish checked on about 100 elk from the same herd Thursday, and none were exhibiting any symptoms. The department will continue to monitor the herd in the coming days and weeks.
"Right now we're assuming that the two elk collected and the one found dead were ill from lichen ingestion, but we don't know that," Hiatt said. "We don't know yet if there's any reason to put the animals through the stress of something like hazing."
This year, as opposed to 2004, the lichen has been covered by snow for most of the winter, he said, and it was only uncovered following a brief warm spell in the latter half of February. A recent snowstorm has reburied most of the lichen, and the elk in the area still have native grasses and shrubs available for sustenance.
The die-off four years ago followed an exceptionally dry summer that didn't produce much forage, and the elk didn't have much else to eat, Hiatt said.
Becky Daily, a doctoral candidate at the Wyoming State Veterinary Laboratory who is doing research on the lichen phenomenon, said it was too early Friday to make a definitive call as to what was ailing the Red Rim elk.
"We did the necropsies last night, so we don't know much of anything yet," Daily said. "We'll know a little bit more at the end of next week, after we've conducted some testing."
Environment reporter Chris Merrill can be reached at chris.merrill@trib.com or at (307) 267-6722.