The spectacled bear (Tremarctos ornatus), also known as the Andean bear and locally as ukuko, jukumari, or ucumari, is the last remaining short-faced bear (subfamily Tremarctinae) and the closest living relative to the Florida spectacled bear^[2] and short-faced bears of the Middle Pleistocene to Late Pleistocene age.^[3][4] Spectacled bears are the only surviving species of bear native to South America, and the only surviving member of the subfamily Tremarctinae.

Description

The spectacled bear is the only bear native to South America and is technically the largest land carnivore on that continent, although as little as 5% of its diet is composed of meat. South America's largest obligate carnivore is the jaguar. Among South America's extant, native land animals, only the Baird's and South American tapirs are heavier than this species. The spectacled bear is a mid-sized species of bear. Overall, its fur is blackish in color, though bears may vary from jet black to dark brown and to even a reddish hue. The species typically has distinctive beige-coloured markings across its face and upper chest, though not all spectacled bears have "spectacle" markings. The pattern and extent of pale markings are slightly different on each individual bear, and bears can be readily distinguished by this. Males are a third larger than females in dimensions and sometimes twice their weight.^[5] Males can weigh 100–200 kg (220–440 lb), and females can weigh 35–82 kg.^[6] Length can range from 120 to 200 cm (47–79 in), with a tail length of a mere 7 cm (2.8 in), and shoulder height from 60 to 90 cm (24–30 in). Compared to other living bears, this species has a more rounded face with a relatively short and broad snout. In some extinct species of the Tremarctinae subfamily, this facial structure has been thought to be an adaptation to a largely carnivorous diet, despite the modern spectacled bears' herbivorous dietary preferences.^[7][8][9]

Distribution and habitat

They are found in several areas of northern and western South America, including eastern Panama,^[10] western Venezuela,^[11] Colombia, Ecuador, Peru, western Bolivia, and northwestern Argentina. The species is found only in the Andes Mountains. The spectacled bear has a reputation for being adaptable, as it is found in a wide variety of habitats and altitudes throughout its range, including cloud forests, high-altitude grasslands, dry forests and scrub deserts. Occasionally, they may reach altitudes as low as 250 m (820 ft), but are not typically found below 1,900 m (6,200 ft) in the foothills. They can even range up to the mountain snow line at over 5,000 m (16,000 ft) in elevation.^[12][13]

Naming and etymology

Tremarctos ornatus is commonly referred to in English as the "spectacled bear", a reference to the light colouring on its chest, neck and face, which may resemble eyeglasses 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. Ornatus, Latin for "decorated", is a reference to the markings that give the bear its common English name.

Behavior and diet

A spectacled bear skull

Spectacled bear at a zoo in Venezuela

Spectacled bears are one of the half of extant bear species that are habitually arboreal, alongside the American and Asian black bears and the sun bears. 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.^[14] Once up a tree, they often build a platform, perhaps to aid in concealment, as well as to rest and store food on.^[14] 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.^[10] Males are reported to have an average home range of 23 km² (8.9 sq mi) during the wet season and 27 km² (10 sq mi) during the dry season. Females are reported to have an average home range of 10 km² (3.9 sq mi) in the wet season and 7 km² (2.7 sq mi) in the dry season.^[15] 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. However, no human deaths have been recorded by South American state governments. The only predators of cubs are cougars and jaguars, though the latter normally has considerably different habitat preferences. Generally, the only threat against adult bears is humans.^[16] The longest-lived captive bear, at the National Zoo in Washington, DC, attained a lifespan of 36 years and 8 months. Lifespan in the wild has not been studied, but bears are believed to commonly live to 20 years or more.^[12]

Spectacled bears are more herbivorous than most other bears; normally about 5 to 7% of their diets is meat. The most common foods for these bears include cactus, palm nuts, bamboo hearts, orchid bulbs, fallen fruit on the forest floor, and unopened palm leaves. They will also peel back tree bark to eat the nutritious second layer. Much of this vegetation is very tough to open or digest for most animals, and the bear is one of the few species in its range to exploit these food sources. These bears also eat cultivated plants, such as sugarcane, honey, and corn, and have been known to travel above the tree line for berries and bromeliads. Animal prey is usually quite small, but these bears can prey on adult deer, llama and domestic cattle and horses.^[17][10] Animal prey has included rabbits, mice, other rodents, birds at the nest (especially larger, ground-nesting birds), arthropods, and carrion.^[18] They are occasionally accused of killing livestock, especially cattle, and raiding corn fields.^[14] Allegedly, some bears become habituated to eating cattle, but the bears are actually more likely to eat cattle as carrion and some farmers may accidentally assume the spectacled bear killed them. Due to fear of loss of stock, bears may be killed on sight.^[19][20]

Reproduction

Mating may occur at almost any time of the year, but activity normally peaks in April and June, at the beginning of the wet season. The mating pair are together for one to two weeks, during which they will copulate multiple times. Births usually occur in the dry season, between December and February. The gestation period is 5.5 to 8.5 mo. From one to three cubs may be born. The cubs are born with their eyes closed and weigh about 300 g (11 oz) each. Although this species does not give birth during the hibernation cycle as do northern bear species, births usually occur in a small den and the female waits until the cubs can see and walk before she leaves with them. The size of the litter has been positively correlated with both the weight of the female and the abundance and variety of food sources. The cubs often stay with the female for one year before striking out on their own.^[10][12][13]

Conservation

A spectacled bear at the Houston Zoo

The spectacled bear population is under threat for a number of reasons. The bears are hunted by locals due to a belief they will eat livestock (although spectacled bears do not eat large quantities of meat). Their gall bladders are also valued in traditional Chinese medicine and can fetch a high price on the international market. Perhaps the most epidemic problem for the species is extensive logging and farming, which has led to habitat loss for the largely tree-dependent bears. As the bear's food sources have been disappearing, it relies on crops for food. So, farmers see the bears as competition and hunt them. Legislation against hunting the bears exists, but is rarely enforced.^[21]

Media

In the documentary Paddington Bear: The Early Years, British actor Stephen Fry encounters a spectacled bear called Yogi, which was kept in a small cage by Andean villagers (see also Paddington Bear). Fry bartered with the villagers to have the bear released, and it was taken to an enclosure in Machu Picchu. Fry's interest in the bears led to the follow-up documentary, Stephen Fry and the Spectacled Bears, and he also wrote and published his experiences in Rescuing the Spectacled Bear: A Peruvian Diary.

In the BBC television programme Serious Andes, a team of eight teenagers built a prerelease enclosure for two spectacled bears before returning them to the wild. The BBC documentary "Spectacled Bears: Shadows of the Forest" looks at some of the bear research being done in Peru and Ecuador and what the researchers are discovering.

References