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Bear Ecology

The ecology of the Andean bear, Tremarctos ornatus, is still being investigated, by this project and others, and there is still much to learn.  
Range & habitat: The elusive Andean Bear lives in the Andes Mountains.  It the only species of South American bear, found in a narrow strip running from western Venezuela through the Andes in Colombia, Ecuador, Peru, and Bolivia, and ending in northwest Argentina.  Bear habitat can include cloud forests, dry forests and paramo or high grasslands.  The distribution of the Andean bear is predominantly restricted by geographical boundaries like deserts (e.g. the Atacama desert accounts for the complete lack of bear populations in Chile).  Bears are an "endangered" species in Ecuador, mostly due to habitat fragmentation caused by livestock farming and logging.  Farmers sometimes shoot the bears because they eat corn (this is illegal). 
Appearance:  The Andean bear has a shorter nose than the other 7 bear species, similar to that of a dog. The Andean bear has a long, thick black coat, except around the muzzle, which is tawny or brown, often with white or brown marks around the eyes (from which it gets its common name, the spectacled bear) that may extend to the throat and chest.  Not all spectacled bears have "spectacle" markings, some have plain black faces, which is why scientists prefer to refer to them as Andean bears.
Bear size: Male Andean bears are much larger than females, with males often growing to a size of 2.2 metres from head to toe. The largest male Andean bear ever recorded measured 2.4 metres. Males may weigh up to 200kg. Females are much smaller, rarely exceeding heights of 1.6 metres from head to toe.  The Andean Bear is smaller than polar bears and grizzly bears, but larger than sun bears and asian black bears.  Andean bears are just a little smaller than American black bears.  
Bear lifespan: The bears' lifespan in the wild is probably rarely longer than 20 years due to the stresses of natural life and sporadic food availability.  Andean bears may live as long as 35 to 40 years in captivity. 
Senses:  Like all bears, Andean bears have a highly developed sense of smell (olfaction).  Their vision and hearing senses are adequate but inferior to their sense of smell.  
Bear diet: Andean bears have a varied diet.  Taxonomically they are classed as carnivores, although they are omnivorous and opportunistic feeders and in reality are predominantly vegetarian.  Like all ursids (bears) they have a sweet tooth and enjoy honey from any bees' nests or honeycombs they find.  In the forest the bears eat palmitos (hearts of palm), the soft insides of suro (Chusquea sp.) (a kind of bamboo), the soft bases of huaycundos (bromeliads), and various types of fruits.  In the paramo, they eat the soft bases of puyas (Puya sp., see photo to the right) and a huckleberry-like fruit called mortiño (Vaccinium sp.).  With forests increasingly being felled and replaced by cornfields, bears have developed the taste for sweet corn or maize.  Although this is not a natural food source, in the corn season a bear's diet consists of a large proportion of maize. 
Like all carnivores, Andean bears need a source of protein for tissue growth.  The bears dig in the earth in search of beetles, worms and insects as a source of protein, and occasionally feed on small mammals.  In very rare cases, in a few parts of their range, there have been incidents of male bears attacking livestock.  This is believed to be due to a lack of food in the forest forcing bears to search for food elsewhere.  Unlike felines, the bears don’t go for the jugular, but jump on the cow's back and take chunks out of the tender shoulder region while the cow is still alive.  Even if the cow survives this attack, it will probably be killed as its neck or spine snap when the bear drags it to a more sheltered spot to eat.   Andean bears are very strong and an adult male can drag a fully-grown cow or even a bull.
Taxonomy: the Andean bear is classified as a mammal, a carnivore, an Ursidae (bear) and the only surviving species of the shortfaced bears, the Tremarctinae.
Ecological Role:  Andean bears are a keystone species, playing a major role in maintaining the dynamics of the cloud forest ecosystem they live in.  The bears in the Intag region of Ecuador are known to rip the bark off Brunelia trees.  This causes the premature death and fall of the trees, creating clearings in the forest, allowing light to get through to the undergrowth, which permits smaller trees to grow and therefore promotes new life in the forest.  Andean bears are very agile and often climb trees in search of bromeliads and fruits.  In doing this, and jumping from tree to tree, they may break branches  which again allows light to pass down to the undergrowth, and so promotes new growth.  By eating fruits of the forest, the bears disperse seeds to other parts of the forest in their faeces.  This is another method by which the Andean bear promotes natural regeneration of the cloud forest ecosystem, which is vital as the "lungs" of the planet and to maintain the natural water cycle.
This role of the bear as a keystone species in its ecosystem means that it is important that the Andean bears are protected and supported with conservation initiatives if the cloud forest itself if to be saved, along with all the other wildlife it supports.  To understand what needs to be done to conserve the bears, we are studying bear behavior.
Andean Bear Conservation Project: Bear Ecology
Ecology of the Andean bear, including bear habitat, range, diet, size and lifespan of the bears and their role as a keystone species.
Andean bear in tree
Male andean bear, taller than a man.
Andean bear in forest
Andean bear eats maize
Andean bear diet: the remains of a puya plant eaten by a bear
Andean bear habitat: paramo landscape