Apparent low toxicity of yew in grazing animals

I HAVE been following the correspondence regarding feral deer browsing on native yew trees ( VR , February 20, 2010, vol 166, [p 246][1]; February 13, 2010, vol 166, [p 216][2]). Roe deer ( Capreolus capreolus ) regularly browse this plant, as attested to by the browse lines in the woods surrounding