neck and face, which may resemble spectacles in some individuals, or the "Andean bear" for its distribution along the Andes. The root trem- comes from a Greek word meaning "hole"; arctos is the Greek word for "bear". Tremarctos is a reference to an unusual hole on the animal's humerus. , Latin for "decorated", is a reference to the markings that give the bear its common English name. Phylogeny A 2007 investigation into the mitochondrial DNA of bear species indicates that the subfamily Tremarctinae, which includes the extant spectacled bear, diverged from the Ursinae subfamily approximately 5.7 million years ago. Tremarctinae includes the extinct American giant short-faced and Florida short-faced bears. Behaviour and diet Spectacled bears are one of four extant bear species that are habitually arboreal, alongside the American black bear (Ursus americanus) and Asian black bear (U. thibetanus), and the sun bear (Helarctos malayanus). In Andean cloud forests, spectacled bears may be active both during the day and night, but in Peruvian desert are reported to bed down under vegetative cover during the day. Their continued survival alongside humans has depended mostly on their ability to climb even the tallest trees of the Andes. They usually retreat from the presence of humans, often by climbing trees. Once up a tree, they may often build a platform, perhaps to aid in concealment, as well as to rest and store food on. Although spectacled bears are solitary and tend to isolate themselves from one another to avoid competition, they are not territorial. They have even been recorded to feed in small groups at abundant food sources. Males are reported to have an average home range of during the wet season and during the dry season. Females are reported to have an average home range of in the wet season and in the dry season. When encountered by humans or other spectacled bears, they will react in a docile but cautious manner, unless the intruder is seen as a threat or a mother's cubs are endangered. Like other bears, mothers are protective of their young and have attacked poachers. There is only a single reported human death due to a spectacled bear, which occurred while it was being hunted and was already shot. The only predators of cubs include cougars (Puma concolor) and possibly male spectacled bears. The bears "appear to avoid" jaguars, but the jaguar has considerably different habitat preferences, does