At some level, absolutely. Everything is.
My experience so far with Oak hasn't been a problem. We have two large oak trees that sit on the border between our pasture and the duck yard. Every other year they drop several hundred pounds of acorns, and every year they drop all their leaves.
The...
The problem with these sort of lists is that they're almost always pulled from the USDA's list of plants toxic to livestock - which the USDA clearly states isn't really a verified product. Plants are added in a non-species specific manner, and are added based on reports form farmers,etc - the...
This is really only true when you're talking about plants and animals in their natural habitats. White tailed deer in the USA have been naturally selected against eating poisonous plants that are common in the USA - but they haven't really been selected for invasives, foreign ornamentals...