BY KAREN BOSSICK
Five elk have been found dead in the Wood River Valley after eating toxic yew plants.
Two cows and a calf were found dead north of Hailey near the Valley Club. Another calf was found just north of Hailey and a yearling was found in Sun Valley.
Idaho Fish and Game conservation officers confirmed the presence of yew in the elks’ digestive system but have yet to find the plant or plants the elk nibbled on. A field necropsy showed that the elk were weathering the winter well, evidenced by ample rump and back fat reserves and healthy bone marrow, said Terry Thompson, regional communications manager for Idaho Fish and Game in the Magic Valley Region.
The exotic yew is an ornamental evergreen tree that contains highly poisonous chemicals known as alkaloid taxines that can be deadly to wildlife, dogs, cats, rabbits, horses, cows and even humans. The Japanese and European varieties of yew, also known as Taxus cuspidate and Taxus baccata, are particularly toxic.
Blaine County commissioners passed an ordinance in 2016 restricting the planting of yew after at least 20 elk died from eating yew plants in the winters of 2015 and 2016. The ordinance prohibits the sale, planting and possession of the plants, including Chinese yew or Taxus chinensis. Homeowners can be fined for violations.
Homeowners are asked to inspect the landscaping around their homes and remove all yew plants in order to keep wildlife and pets safe, especially during winter when wildlife moves into historic winter range now occupied by homes.
If removal is not possible until spring, the bushes should be tightly wrapped with burlap or the bushes fenced so wildlife can’t get access.
“I realize that it’s hard to dig up mature landscaping, but everyone needs to do the right thing for wildlife, and even to protect your pets, by removing plants like exotic yew,” said Regional Wildlife Manager Mike McDonald. “It takes a surprising small amount of yew to kill an elk, deer or moose, which are all species that residents can see throughout the valley, almost daily.”
Thrushes, waxwings and other birds eat the soft fleshy covering of the seed—the covering being the only part of the yew plant that is not toxic. The birds then disperse the toxic hard seeds in their droppings.
Grazing animals, such as cattle and horses, are sometimes found dead near yew after eating the leaves. And even dried branches can be fatal. Only a handful of needles are needed to kill horses, elk or dogs. Pronghorn, moose and deer also have fallen victim to the plant over the past several years in Idaho.