Virus Hits West Herds
Wyoming affected by EHD; Elk dies of lichen poisoning
Continued concern over a deadly deer virus is moving westward, as wildlife officials in Wyoming are expecting what could be the worst die-off in decades at and around the Black Hills region in the northeastern part of the state.
Epizootic hemorrhagic disease has been confirmed in as many as 15 states in recent weeks
“Our deer numbers are down right now anyway, and this sure isn’t helping anything,” said Joe Sandrini, a Wyoming Game and Fish Department biologist based in Newcastle, Wyo.
Officials had said they expected a die-off due to EHD, thanks in part to drought conditions this summer that have allowed biting midge flies to flourish. The flies carry EHD.
They won’t know the extent of the die-off until mid-October after they begin calculating herd estimates. It seems to be worse in the northern part of the Black Hills, Sandrini said.
Since early September, concerned residents have called to report dozens of dying deer. Deer infected with EHD may appear depressed or feverish. Other signs may include blue-tinted tongue or eyes, ulcers on the tongue, sloughed hooves, high fever and swelling of the head, neck, tongue or eyelids.
“I’ve not had this many calls ever before, even during an outbreak,” said Chris Teter, who has been a Wyoming game warden for 22 years.
Biologists first found the disease in the Black Hills in the 1950s. The last major outbreak hit around 2005. Some officials wonder if herd immunity to the disease is down – some deer will not die of the disease even if infected – leading to the current situation, Sandrini said.
EHD can also occur in antelope, elk and mule deer, but it cannot be spread to humans or most other wildlife.
Fawn numbers were already low in the region because of the harsh 2010-2011 winter. Deer season in the Black Hills does not open until Nov. 1. Sandrini said he expects the season to proceed as normal, but Wyoming biologists have already set the lowest deer quotas and shortest season in decades.
Also in Wyoming, hunters are being told not to shoot elk that look weak or paralyzed after a dead cow elk was discovered to have died from lichen poisoning.
Officials do not know the possible health effects on humans if meat infected by lichen poisoning is eaten, Daryl Lutz, Lander regional wildlife supervisor for the Wyoming Game and Fish Department, told the Casper (Wyo.) Star-Tribune.
The dead cow elk was discovered near Wamsutter and tests confirmed it died of lichen toxicosis. Game specialist Rene Schell told radio station KVOW/KTAK that the elk was over 15 years old. It was alert when found, but unable to stand. Cynthia Tate of the Wyoming State Wildlife Veterinary Lab said it had the classic symptoms of the lichen poisoning, including paralysis, red-colored urine, damage to muscle cells and a paunch full of lichen.
Lichen are composite organisms consisting of a symbiotic relationship between a fungus and a photosynthetic partner, usually a green alga. Some types have the aspect as leaves, while others cover ground or tree bark like a crust.
Tumbleweed shield, a toxic lichen, was abundant where the cow was found and is common in sagebrush habitats across the West. The tumbleweed lichen causes long term and lasting muscle paralysis in affected elk. The presence of the lichen will not in itself cause elk to die, rather they likely succumb to predation or starvation.
Lichen poisoning has been a problem in Wyoming elk in the last decade. More than 500 elk died from lichen in the winters of 2004 and 2008.
The Wyoming Game and Fish Department is asking citizens to report any elk that look sick or are behaving oddly.
Over the last few years, game managers have attempted to keep elk away from areas known to contain lichen. Methods have included hazing them with snowmobiles and luring them elsewhere with hay.