In 2004, something was slowly killing hundreds of elk in Wyoming. Wildlife biologists and veterinarians ruled out viruses, bacteria, heavy metal poisoning, brucellosis and wasting disease before finally determining that the culprit was a native lichen the elk had ingested because there was nothing else to eat.
Now, New Mexico game officials are in a similar quandary. They are trying to figure out what killed more than 100 elk within 24 hours last week on a private ranch north of Las Vegas, N.M.
The elk weren’t shot or struck by lightning. Tests have ruled out poisonous plants, seeds and anthrax, a bacteria that can hide dormant for years in soil.
The cause of the die-off could still be a virus or something in the ranch’s water tanks.
Ultimately, this is a mystery that might never be solved. “It is possible we won’t have a definitive answer,” said Kerry Mower, wildlife disease specialist with the New Mexico Department of Game and Fish.
The elk death mystery has some hunters worried.
Max Trujillo, a Las Vegas hunter, said he has had calls from other hunters concerned about whether or not it is safe to eat elk they bag in the area. Game officials are urging hunters to report any elk or other game that look or act abnormal.
“It is kind of scary. If in fact it is something coming from a fly or insect and it is airborne, it can be carried for miles,” Trujillo said.
“It’s a bummer, a sad thing,” Trujillo said. “More than three-quarters of the elk were cows and calves. Over 10 years, that translates to 1,000 elk that would have come from that herd.”
He said it’s the biggest elk die-off in the state that he’s heard of. And Game and Fish officials said no other game die-offs have been reported in the state.
The dead elk were reported Aug. 27 by a hunter that found them scattered across less than a one-square-mile area of the 75,000-acre Buena Vista Ranch. New Mexico Department of Game and Fish officials ruled out poachers. Tissue samples from the elk and water samples from the ranch were collected and sent to veterinary diagnostic labs in New Mexico, Texas and Georgia.
Mower said pathologists quickly ruled out anthrax. That was good news for Mower, since he would have already been exposed to any potential anthrax bacteria spores. “Anthrax is such a serious risk to human, livestock and wildlife health,” Mower said.
Mower said it is still possible a virus, such as the one that causes epizootic hemorrhagic disease, might have killed the elk. But he said some aspects of the deaths don’t match the disease. Usually, an infectious disease will sicken a number of animals, kill some and leave a few standing. The affected animals will be strung out over a wide swath of land and won’t all get sick at once.
“This really is quite an event to have so many animals die so abruptly,” Mower said.
He took water samples from eight tanks around the ranch to test for heavy metals, such as arsenic and selenium, and for nitrates. He said a heavy metal concentration can be natural but usually is a side effect of a pesticide application. “We don’t know of anything in that area that’s a natural concentration of heavy metals,” he said.
Investigators also found no evidence of large-scale pesticide use on any nearby hay fields.
Mower said they haven’t found evidence or had reports of any other dead or sick elk or cattle in the area or on neighboring ranches, and he thinks this incident is isolated.
The dead elk were in Game Management Unit 46, where the bow hunting season started Sunday, and muzzle load hunts begin in mid-September.
Weather played into the Wyoming elk deaths, and some believe it’s possible that weather also played a role in the New Mexico elk deaths.
The elk began dying in Wyoming in the spring, following one of the hottest, driest summers on record, according to the Wyoming Tribune Eagle at the time. Game officials said the lack of normal grass drove more elk into an area where they didn’t normally browse. By April, more than 400 elk deaths were linked to the lichen.
In 2012, a combination of drought, heat and stress killed several elk in Missouri.
New Mexico is in at least its third year of severe drought, and the northeastern portion of the state was hard hit. Recent rain stimulated a spurt of fast-growing, rich grass, some of the best in the state, Mower said. “It could be the runoff water washed something into the dirt [water] tank or quick-growing plants have taken something [toxic] up,” Mower said.
He said it could be a couple of weeks before all the tests on the elk tissue and water samples are complete.
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