Five Idaho Elk Poisoned by Yew Landscaping Plants

by TK Sanders
(Photo by: Arterra/Universal Images Group via Getty Images)

Five elk died in central Idaho recently after eating a plant called ornamental yew. Normal neighborhood landscapes often feature the plant, which is toxic and deadly to many animals. Housing communities have sprung up in recent years in the elk herd’s historic winter range, leading to exposure to the yew.

Livestock and pets also suffer poisonous reactions to the yew; though birds can eat the berries without harmful side effects. Mammals, however, break down yew needles and seeds, causing the release of harmful toxins. No more than a handful of the plant’s needles is needed to kill a large animal like an elk.

The USDA says that the animals usually die within two days of ingesting the yew. But adverse reactions begin almost immediately.

According to the Idaho Department of Fish and Game (IDFG), the elk died north of Hailey, Idaho. Elk have been dying from poison yew in the area for years, most recently in the winter of 2015 when at least 20 of them died.

As snow accumulates at higher elevations in the winter, big game like elk move down into the warmer valleys to look for food and water. Resort towns like Hailey and Sun Valley, both located in Blaine County, see an uptick in elk and other mammals during the winter.

Blaine County has tried to prevent elk poisoned by yew in the past

Blaine County tried to mitigate the damage in 2016 by unanimously passing a noxious weed ordinance banning yew and other poisonous ornamentals. Many different variations of yew, including Chinese, Japanese, European, and hybrids, are banned by the ordinance. Violations result in a misdemeanor fine of $3,000. Clearly, though, enough plants still exist in the area to kill more elk.

“I realize that it’s hard to dig up mature landscaping. But everyone needs to do the right thing for wildlife. [Everyone needs] to protect their pets by removing plants like exotic yew,” said Mike McDonald, Idaho Department of Fish and Game regional wildlife manager. “It takes a surprisingly small amount of yew to kill an elk, deer, or moose. [They] are all species that residents can see throughout the valley almost daily.”

IDFG officials are searching for the property where the elk ate the ornamental yew. So far, they do not know where it came from, but they are still encouraging property owners to remove the plants as often as possible. If the homeowner cannot pull the plant out of the frozen ground, then he or she should wrap the plant until the spring thaw, according to the IDFG.

Post-mortem analysis of the elk showed healthy tissue and bone marrow. They also had ample rump and back fat, which means that they were enjoying a snack in town, not desperate for food. As a result, local officials believe that the elk are otherwise thriving, and that removal of the yew will mitigate most future loss of life.