When you say it eats various ferines...can you specify? Since they're trees, they probably can't be eaten in their entirety, or eaten almost in their entirety, without special adaptations for eating wood. I figure the parts that could be eaten without special adaptations, especially considering they can cook it, would be the berries, flowers, flower buds, leaf buds, possibly shoots, and cambium. (except sleeve ferines, which is probably high in heavy metals) Since that's a long list, you could say "most low-cellulsoe parts of".
Would they avoid eating Scarlethorns?