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Yew Berries and Bears - UPDATE December 27, 2016

A Lily Fan wrote: “I saw an article yesterday about black bears in PA dying from eating yew berries (Taxus). Since I observed a black bear eating the berries from my yew bushes last summer, this had me very upset!Red squirrel restingRed squirrel resting Do you know whether this is true? The bear was back multiple times for these berries. If it's true I will most certainly remove these bushes. Thanks!”

I’d never heard about anything like this with bears. The main thing I knew about the native yew (Taxus Canadensis) of the northeastern United States was that white-tailed deer wipe them out with their browsing when deer are abundant. I never heard of a deer dying from it. I looked it up on the internet just now. White-tailed deer apparently are resistant to yew toxins.

I copied and pasted some passages about their toxicity and included links in case you want to read more.

The first passage, a recent posting by Pet Poison Helpline, says horses are very sensitive to yew toxins.

Yew (unknown source)Yew (photo unknown source)In the second passage, written in (2008), the author believes his report of a moose dying from yew poisoning is the first report of yew intoxication in a wild animal species.

The next article, written in 2006, says it is probably okay to eat the arils (berries) if you don’t eat the seeds.

The article written in 2007 says that wild deer, moose and elk browse on yews as winter food and are not affected by the yew toxin.

The last passage is from Wikipedia, last updated in 2016. It says all parts are toxic except the aril. They probably meant red fleshy part of the aril.

If the seed is the poisonous part of the aril, it is surprising that a family of bears died from it because they usually swallow seeds whole and pass them through unbroken. However, I remember one bear that did crunch his seeds, so I guess anything can happen.

On a happier note, a red squirrel stopped and rested on a branch outside the window for a few minutes. I know how that feels. Sometimes I have to take a half hour nap to refresh my mind. The squirrel got by with less than that and did it with its eyes open. I guess they have to be alert even while sleeping, if that is possible. I remember the deer I used to walk with. To ingest food, they would chew it just enough to swallow it. After they had eaten quite a bit, they’d go to a place where they were partially concealed but could see around, usually in a balsam fir thicket where they could see out under the branches. There, they’d chew their cuds. After awhile, they’d tuck their heads and sleep for a very few minutes. Then they were up foraging again. The squirrel today finally perked up and ran down the branch and down the tree to resume foraging for sunflower seeds.

Thank you for all you do. See below for the passages.

Lynn Rogers, Biologist, Wildlife Research Institute and North American Bear Center

www.petpoisonhelpline.com/poison/japanese-yew/
This common evergreen (meaning the plant stays green all year round) is extremely poisonous to all species (e.g., dogs, cats, horses, cattle, humans, etc.). All parts of the plant (including the succulent, red berries) are very poisonous, as they contain taxines. There are several variety of plants in the Taxus spp., including the Japanese Yew and English Yew. When ingested by dogs and cats, clinical signs of drooling, vomiting, weakness, difficulty breathing, life-threatening changes in heart rate and blood pressure, dilated pupils, tremors, seizures, coma and death may be seen. Recently, florists have started to use Japanese Yew to make wreaths for the holidays. As horses are very susceptible to yew poisoning, make sure not to have this around the barn or pasture!

https://www.ncbi.nlm.nih.gov/pubmed/18793664
Acute yew (Taxus) intoxication in a free-ranging moose (Alces alces) is reported. The moose was found dead without any signs of struggle and post mortem examination revealed general congestion, bilateral heart dilatation, and the presence of yew in rumen. The animal was found adjacent to a housing estate with unfenced gardens, surrounded by woods and open fields without native yew. The vast majority of the gardens contained cultivars of yew that had frequently been browsed upon. These were the most likely source of intoxication. This is believed to be the first report of yew intoxication in a wild animal species. It is concluded that yew intoxication may be an overlooked diagnosis in wild deer, and the general opinion that deer species are naturally resistant to many plant-associated toxins is discussed.

http://livinginseason.blogspot.com/2006/12/yew-tree-of-winter-solstice.html
The fruit of the yew is called an aril. They look like soft, squashy red gumdrops with a hole in one end. Although many people believe they are poisonous (the foliage and bark of the yew are), the berries are edible, although the hard seed inside is not. Birds love the fruit and that’s how the yew is distributed, as the seed passes through their digestive tracts intact. The leaves are so poisonous that eating as little as 50-100 grams of chopped leaves would be fatal to an adult human. I found a website about poisonous plants and horses that mentioned that yew was so toxic that horses were frequently found dead with yew leaves still in their mouths

http://www.omafra.gov.on.ca/english/livestock/horses/facts/07-055.htm
The genus Taxus consists of three commonly grown ornamental shrubs - English yew, Canada yew and Japanese yew - and hybrids. The needles and seeds of all yews are highly poisonous to horses, cattle, sheep and goats, although the red, fleshy seed covering is not. Humans, particularly children, are also susceptible to the toxins in these plants.

https://en.wikipedia.org/wiki/Taxus_canadensis
Taxus canadensis, the Canada yew[2] or Canadian yew, is a conifer native to central and eastern North America, thriving in swampy woods, ravines, riverbanks and on lake shores. Locally called simply "yew", this species is also referred to as American yew or ground-hemlock. The seed cones are highly modified, each cone containing a single seed partly surrounded by a modified scale which develops into a soft, bright red berry-like structure called an aril, open at the end. The seeds are eaten by thrushes, waxwings and other birds, which disperse the hard seeds undamaged in their droppings. The male cones are globose, 3 mm diameter. It is a monoecious plant – one of the few in the genus. All parts of Canadian yew, save the aril, are toxic; it is, however, thought to be of lower toxicity than T. baccata.


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