Wildlife officials knew some deer would die in the Black Hills this fall. No one expected what could be the worst die-off in decades.
Called epizootic hemorrhagic disease, or EHD, the disease typically strikes fawns and bucks and is worse during droughts. Biologists first found the disease in the Black Hills in the 1950s.
“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.
The disease is spread by a type of biting gnat. White-tailed deer are most often affected. It’s worse during dry years because deer congregate in larger groups near diminishing water sources. A hard frost will kill the gnats, but when temperatures don’t drop low enough, the gnats — and the disease — persist, Sandrini said.
It cannot be spread to humans or most other wildlife and is not a threat to humans, Sandrini said.
Dying deer may be lethargic, appear to be drooling and congregate near water. If a deer succumbs to the disease, it typically dies within three days of infection, Sandrini said.
Biologists won’t know the extent of the die-off until mid-October after they begin calculating the herd estimates. It seems to be worse in the northern part of the Black Hills, Sandrini said.
Sundance Game Warden Chris Teter started fielding calls from concerned residents around the first of September and has since received dozens reporting dead or dying deer.
“I’ve not had this many calls ever before, even during an outbreak,” said Teter, who has been the game warden for 22 years.
The drop in fawn numbers will hit the population particularly hard. It is still trying to recover from the harsh 2010-2011 winter, Sandrini said.
Deer hunting season in the Black Hills does not open until Nov. 1. Sandrini expects the season to proceed as normal. Wyoming biologists have already set the lowest deer quotas and shortest season in decades.
The disease is widespread, killing deer in 15 other states, he said.
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, he said.
The disease can also occur in antelope, elk and mule deer.