Pack animal Pack animal A pack animal or beast of burden is an individual or type of working animal used by humans as means of transporting materials by attaching them so their weight bears on the animal's back, in contrast to draft animals which pull loads but do not carry them. Traditional pack animals are diverse including camels, goats, yaks, reindeer, water buffaloes, and llamas as well as the more familiar pack animals like horses, donkeys and mules. The term "pack animal" is traditionally used in contrast to "draft animal", which is a working animal that typically pulls a load behind itself
Tree girth measurement tree and by extension the girth should be measured with respect to the same base point. This point is fixed at the same location over time as the tree grows. In addition this is a reference point that is present and consistent in all trees no matter the height of the girth measurement. Even if the girth is measured at a non- standard height because of low branching, a large burl, or even on the upslope side of a large girth tree on sloping ground, all heights can still be consistently referenced to this single point present on all trees.