BY TERRY THOMPSON

The recent death of a moose north of Ketchum in the Hulen Meadows subdivision has renewed concerns about wildlife eating ornamental yew plants, which are deadly to anything that eats the plant.

Fish and Game officers were unable to determine the cause of death of the mother moose, which died last week, since a necropsy was not performed before a landscaper removed the moose  from the area. The immediate area was searched for yew plants but none have been found to date. 

During the winter of 2021-22 more than 20 elk died from eating ornamental yew throughout the Wood River Valley. Several plant species are toxic to wildlife and pets, especially those in the yew family.

Residents should inspect the landscaping around their homes and remove all yew plants to keep wildlife and pets safe, especially during winter months when wildlife moves down into historic winter range, now occupied by community neighborhoods and private residences.

Yew plants are evergreen, even in winter, which is thought to be the reason why reports of wildlife eating the plant seem to be more common during winter months.

Homeowners should completely remove any yew from their yards. If removal is not possible until spring, the bushes should be securely fenced so that wildlife cannot get access to the plants, or the plants should be tightly wrapped with burlap. 

Yew toxicity

Many plants contain toxic chemicals which may be dangerous to humans, pets, and wildlife.  Yew is an evergreen tree commonly used in ornamental plantings or landscaping that contains highly poisonous chemicals known as alkaloid taxines. Two species of yew, Japanese and European, are particularly toxic.

All parts of ornamental yews except the arils, the material that covers the seeds, contain toxic alkaloids. The arils are edible and sweet, but the seeds, needles and stems are dangerously poisonous.

The yew seeds are eaten by thrushes, waxwings and other birds, which digest the soft fleshy covering of the seed and disperse the hard seeds undamaged in their droppings.

In mammals, the digestive process can break down the leaves or seed coat and release the taxines into the body. This can have fatal results if yew berries are eaten without removing the seeds first.

Grazing animals, particularly cattle and horses, are also sometimes found dead near yew after eating the needles. Dried branches can also be fatal.

Ornamental yews and related plants are toxic to a variety of animals including horses, cattle, dogs, cats, rabbits, birds, deer, elk, and even humans.

Ornamental yews are highly toxic with only a small handful of needles needed to kill horses, elk or dogs.

Blaine County ordinance

In February 2016 the Blaine County Board of County Commissions unanimously passed County ordinance number 2016-01, declaring certain plant species as County noxious weeds and prohibiting the sale, planting, and possession of any plant on the County noxious weed list with penalties for violations.

Plants included on the County noxious weed list include Japanese yew (Taxus cuspidata), European or English yew (Taxus baccata), and Chinese yew (Taxus chinensis) and their hybrids.

The cities of Ketchum and Hailey have also adopted the yew ordinance, prohibiting yew from properties within their respective city limits. 

The Ohio Gulch Transfer Station accepts yew debris free of charge, but the yew must be separate from other yard debris. Due to the extreme toxicity of yew, proper removal includes removing all traces, no matter how small.

For more information, contact the Blaine County Noxious Weed Department at 208-788-5574, Ketchum City at (208) 726-3841, City of Hailey at (208) 788-4221, or the Idaho Fish and Game, Magic Valley Regional Office at (208) 324-4359.