Richardson 1937 Yellow-haired Porcupine (Erethizon spixianum) June 4, 1937 - Barley Camp, Homer Mts., Oregon - A large adult was discovered in juniper-sagebrush association. It was descending slowly down a small juniper - using the tail as support against the tree-trunk. From the tree he proceeded across open ground through the low sagebrush. First was noticed his shivering (especially in comparison to other rodents) unconcern in being exposed and active in broad daylight. It did not apparently look for any enemies at any time. It looked at me on my yelling but went on shortly and just as slowly. On being closely approached (cay 10') he stopped turned his back toward me - araling it to expose the most prom- inent posterior region of spines. On being prodded or very closely approached, this arched position was even more exaggerated, the head being thus better protected or less exposed (probably this same tendency to protect the wild head has been influenced in the evolution of armadillos, hedge-hogs -) and lashed the tail. - A profitable parallel may be made be- tween this animal and the sloth. In both, the (bark or leaf) eating seems correlated with spines or very tough hide, slow movement, poor vision, and climbing adaptations.