Spectacled bear

Name and taxonomy

The English name comes from the pale markings that can ring the eyes like a pair of glasses. Many bears have only partial rings, or none, and the pattern differs on every animal. Andean bear is the other common name, and Spanish speakers say oso de anteojos or oso andino. Quechua speakers call it ukuku or ukumari, and Aymara speakers jukumari. One reading of ukumari is hole bear, because the dark eyes sit like holes in the pale face.

Tremarctos joins the Greek words for hole and bear, after an unusual opening in the upper arm bone. Ornatus is Latin for decorated. The type specimen was said to come from Chile, where the species does not live. The locality is now placed east of Trujillo in Peru. No subspecies are recognised, though colour patterns vary from region to region.

Evolution and relatives

The spectacled bear is the only living member of the subfamily Tremarctinae, the short-faced bears. Its extinct relatives include Arctodus and Arctotherium, giants that vanished about 12,000 years ago. Its sister species, Tremarctos floridanus of North America, was about twice its size. The short-faced line split from the other bears about 5.7 million years ago. The name is misleading: the skull is deep and tall rather than truly short in the face.

The species appears in the South American fossil record only in the Holocene, so its ancestors probably came south late. The oldest remains, a male from Chaquil Cave in Peru, are about 6,790 years old. Its DNA suggests old hybridisation with Arctotherium and a long fall in numbers to about 2,000 breeding animals. It has 52 chromosomes against 74 in Ursus, yet it has crossed with the Asian black bear in captivity.

Appearance

Head and body measure 120 to 200 centimetres, and an adult male is at least 150 cm. The shoulder stands 70 to 90 cm high, and the tail is a stub of about 10 cm hidden in the fur. Males weigh 100 to 200 kilograms, about 115 on average, and females 35 to 82 kg, about 65 on average. Males are a third larger in every dimension and sometimes twice the weight, a gap matched only by the polar bear. One obese zoo male reached 222.5 kg.

The fur is black, sometimes dark brown or reddish, and of medium length. Cream or ginger marks cover the muzzle, run around the eyes and spill down the throat and chest like a bib. Some bears have an almost white face, and others have no marks at all. The build is stocky, with a short neck, small round ears and a short deep muzzle. The front legs are longer than the back legs, which suits a climber, and the claws are short. The jaw muscles are the largest of any bear for its size, built to crush tough plants.

Habitat and range

The bear lives along the Andes in Venezuela, Colombia, Ecuador, Peru and Bolivia, with doubtful records from Argentina and Panama. The range is a ribbon more than 4,600 kilometres long but only 200 to 650 km wide. Wet cloud forest between about 1,000 and 2,700 metres is the best habitat. Bears also use the paramo and puna grasslands above the trees, elfin forest, dry forest and the scrub desert of western Peru. They have been found from 250 metres up to the snow line above 5,000 m.

One population on the Peru-Ecuador border uses as many habitat types as all the world's brown bears together. Bears move up and down the mountains as different foods ripen, but the timing of these moves is unknown. A male's home range averages 23 square kilometres in the wet season and 27 in the dry. A female's averages 10 km2 in the wet season and 7 in the dry. GBIF holds records from 12 countries, most of them from Colombia and Ecuador, and some from zoos.

Diet and feeding

Bromeliads are the staple across most of the range. On the high grasslands the bear tears the spiny leaves off the ground bromeliad Puya to reach a bland heart like a pineapple. In the forest it climbs for Tillandsia, eats the base of the leaves and drops the rest, which litters the ground below. Bromeliads make up anywhere from 90% to under 15% of the diet, depending on season and place. Fruit fills the gap, and the bear can smell from the ground when a tree is ripe.

It also eats palm hearts and nuts, bamboo shoots, orchid bulbs, cactus fruit, moss, and the soft inner bark of trees. In a fruit tree it bends and breaks branches into a platform, then rests and feeds there. Near farms it raids maize and sugar cane, and up to nine bears have fed in one field. Meat is a small part of the diet: insects, snails, rodents, ground-nesting birds and carrion. A radio-collared bear once came 1.5 kilometres to a small piece of beef within 15 hours.

On rare occasions the bear kills large prey. It has been filmed attacking a mountain tapir, and it sometimes takes deer, llamas, unguarded cattle and horses. It overpowers the animal, climbs on its back and begins to eat before the prey is dead. Most cattle it eats, though, are probably found dead, and farmers blame it for kills that were not its own.

Behaviour and social life

The spectacled bear lives alone, except for a mother with cubs. It is not territorial, and ranges of both sexes overlap widely. Where food is rich, at a cornfield or a cactus grove, several bears feed side by side. It is one of only four bears that spend much of their time in trees, with the sun bear and the two black bears. It can climb the tallest trees of the Andes, and that skill has kept it alive alongside people.

At a high site in Bolivia the bears were wholly diurnal: they slept 9 to 12 hours at night and rose at sunrise. Elsewhere they are reported to move at night as well, and bears in the Peruvian desert sleep under cover by day. There is no hibernation, because something is always in fruit or in leaf. A bear that meets a person is calm but wary and usually retreats, often up a tree. It builds platforms of broken branches in trees to hide, rest and store food, and ground nests beside a carcass.

Communication and senses

Smell rules the bear's life. Its nose is extremely sensitive, and it can tell from the forest floor which tree above is loaded with ripe fruit. Hearing is moderate and eyesight is short. Scent is also the main way bears talk to each other. They rub their backs on trunks, claw the bark, and probably urinate at the same spots, leaving messages for the next bear.

At least five distinct calls pass between a mother and her cubs. Courtship involves play and mock fights, and mating is loud from both partners. Like other bears, it probably huffs and clacks its jaws when it feels threatened.

Reproduction and life cycle

Pairs have been seen together from March to October, and mating peaks in April and June as fruit begins to ripen. A pair stays together for one to two weeks and mates many times, for 12 to 45 minutes at a time. Pregnancy lasts 5.5 to 8.5 months, and the wide range points to delayed implantation. In the wild most cubs are born in the dry season, from December to February, a few months before the fruit comes in.

A litter holds one to three cubs, usually two, and four is rare. Each cub weighs about 300 to 330 grams at birth, with its eyes shut, and it does not see for about 30 days. The mother keeps her cubs in a small den for three to four months, until they can see and walk. Bigger, better-fed females bear bigger litters. Cubs nurse for a year and stay with their mother for up to another year.

Both sexes mature at 4 to 7 years, and a female usually has her first litter at about 5. Females can breed every two years. Males stay fertile almost all their lives, and they may kill cubs they meet. A wild bear is thought to live about 20 years, and the oldest captive bear reached 36.7 years.

Predators and threats

No animal preys on an adult spectacled bear. Cougars and sometimes adult male bears take cubs, and jaguars may too where the two species meet. Jaguars mostly live lower down, and the two overlap only about 900 metres of altitude across the whole Cordillera Oriental. The only real enemy of an adult is a person.

Farms, roads, logging and illegal mines have carved the cloud forest into patches. In Ecuador about 40% of the bear's habitat has gone, and the rest is broken into islands. Small isolated populations can die out even without further loss or hunting. Hungry bears turn to maize and cattle, and farmers shoot them on sight. Bears are also killed for meat, for their fat and claws, and for gall bladders sold to the east Asian medicine trade. Trophy hunting was a pastime of rich young men in the 19th century, as the Colombian novel Maria records.

Population and conservation

The IUCN lists the spectacled bear as Vulnerable, and it sits on CITES Appendix I. No reliable count exists, and guesses run from about 13,000 to 25,000 bears. A 1998 survey found only 18.5% of the range inside 58 protected areas, many of them small. The median park among 43 in the northern Andes covered 1,250 square kilometres, probably too small for a lasting population.

Every range country protects the bear by law, but the laws are rarely enforced, even inside parks. Venezuela has run education campaigns since the early 1990s and made the bear an emblem of conservation. The Spectacled Bear Conservation Society was founded in Peru in 2006. Researchers call for corridors that link cloud forest to paramo, for fewer roads, and for schemes that pay farmers to live with bears.

Relationship with humans

People who live far from the Andes see a gentle vegetarian and a symbol of wild places. People who share its mountains often see a cattle thief and a crop pest. Any dead cow is blamed on the bear, though other predators and disease account for many. Raids on maize are real, and they grow more common as wild food shrinks.

Bear parts are traded for folk medicine and ritual, and the meat is prized in some districts. Cubs are still taken as pets, and confiscated bears rarely return to the wild. Only one human death is on record, caused by a bear that hunters had already shot. Mothers with cubs have attacked poachers.

The bear serves the forest in return. It opens bromeliads, spreads the seeds of the fruit it eats, and shapes the cloud forest as it moves. Stephen Fry wrote Rescuing the Spectacled Bear after two BBC programmes on a rescue in Peru.

In culture and myth

In Quechua tradition the ukuku is a being between the human and the wild. In many Andean stories he is the son of a bear and a woman the bear carried off to his cave. Some Andean peoples regard the bear as the mountains' guardian and a link between earth and sky. The same stories of stolen women and children give some people a reason to kill bears.

In Peruvian tradition, dancers in shaggy bear costume called Ukukus keep order at the Qoyllur Rit'i pilgrimage near Cusco. They climb the glacier at night and carry down blocks of ice. A bear figure also dances at the feast of the Virgen del Carmen in Paucartambo. Andean folk belief holds that bear meat gives strength, bear fat cures illness and a claw brings luck.

Oddly, the bear is almost absent from Inca and earlier art, with no known pottery or carvings in its likeness. Scholars still argue about why. In British popular culture, Paddington Bear from darkest Peru is a spectacled bear. Spirit-animal websites make it a symbol of balance and introspection, but that is a modern reading, and probably not Andean.