Spectacled Bear (Tremarctos ornatus)

Spectacled bears are medium-sized bears that are typically uniformly black in color, but brown and reddish-brown individuals have been observed. The Andean bear’s dense coat is of medium to long length and they have a short tail, about 7 centimeters long, (2.8 inches,) that is often completely hidden by the fur. They have a robust, stocky build; rounded head; small, round ears; a short, thick, muscular neck; short but strong legs; and a stout muzzle that is relatively short compared to other bear species.

Spectacled bears have white, cream, beige, pale yellow, ginger, or tan markings on the face that create rings around the eyes and often extend down the chest, forming a bib-like patch of light fur. These lighter markings are highly variable, unique to each individual, and may be absent altogether. Just as humans have different fingerprints, no two bears have the same patterns, allowing individuals to be easily identified from each other.

Andean bears average 60-115 kilograms, (132-254pounds,) but can range from 35-200 kilograms, or 77-441 pounds. They range from 1.2-2 meters, (3.9-6.6 feet,) in length and their shoulders stand at 70-90 centimeters, (2.3-3 feet.)eru. Spectacled bears are the largest land carnivore and second largest terrestrial mammal in South America, after the lowland tapir (Tapirus terrestris).

The spectacled bear rivals the polar bear (Ursus maritimus) for the most sexually dimorphic modern bear. Male spectacled bears are up to 50% larger than females and are sometimes twice their weight. Males typically weigh 100-200 kilograms, (220-441 pounds,) while females range from 35-82 kilograms (77-181 pounds.) On average, males weigh about 115 kilograms, (254 pounds,) and females 65 kilograms, (143 pounds.) Mature males do not measure less than 150 centimeters, or 59 inches, in length.

Relative to their body size, spectacled bears have the largest zygomaticomandibularis muscle of any bear species. This musculature feature, along with the blunt lophs of the cheek teeth, are adaptations for their primarily herbivorous diet.

Like all bears, spectacled bears walk on the soles of their feet and are equipped with a plantigrade stance. Their front limbs are longer than their hind limbs, giving them amazing climbing abilities. Spectacled bears are excellent climbers and spend a fair amount of time in trees.

Not much is known about the average lifespan of a wild spectacled bear, but it is believed to be around 20 years. The average lifespan of Andean bears in captivity is around 25 years. The longest recorded lifespan was at the National Zoo in Washington D.C., where the bear lived to be 36 years, 8 months of age.

SEXUAL DIMORPHISM

Larger Males

SHOULDER HEIGHT

0.7-2 m. / 2.3-3 ft.

BODY LENGTH

1.3-2 m. / 4.27-6.56 ft.

BODY MASS

60-200 kg. / 132-441 lb.

DENTAL FORMULA

I ³⁄3, C ¹⁄1, P ³⁄4⁴⁄₄, M ²⁄3, ×2 = 40-42

LIFESPAN

20-36 yr.

GENERATION LENGTH

10 yr.

LOCOMOTION

Plantigrade

The spectacled bear is a true modern bear and a member of the family Ursidae, along with seven other species, the brown bear (Ursus arctos), the giant panda (Ailuropoda melanoleuca), the polar bear (Ursus maritimus), the Asiatic black bear (Ursus thibetanus), the American black bear (Ursus americanus), the sun bear (Helarctos malayanus), and the sloth bear (Melursus ursinus). Common characteristics of modern bears include large bodies with stocky legs, long snouts, small rounded ears, shaggy hair, plantigrade paws with five nonretractile claws, and short tails.

The spectacled bear is the last remaining short-faced bear from the subfamily Tremarctinae and the Tremarctos genus, endemic to the Americas from the Pliocene to recent.

The spectacled bear’s closest relatives are the extinct Florida spectacled bear (Tremarctos floridanus), a northern species that went extinct 11,000 years ago and the giant short-faced bears of the Middle Pleistocene to Late Pleistocene age.

KINGDOM

Animalia

PHYLUM

Chordata

CLASS

Mammalia

ORDER

Carnivora

FAMILY

Ursidae

GENUS

Tremarctos

SPECIES

ornatus

SUBSPECIES

None

The common name, spectacled bear, comes from the white, cream, beige, pale yellow, ginger, or tan markings on the face that create rings around the eyes. These lighter markings often extend down the chest, forming a bib-like patch of light fur. The lighter markings are highly variable, unique to each individual, and may be absent altogether.

The spectacled bear is also known as the Andean short-faced bear because it has a relatively short, broad snout and more rounded face compared to other bear species. 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 bear’s herbivorous dietary preferences. The spectacled bear is the last remaining short-faced bear from the subfamily Tremarctinae and its closest relatives are the extinct Florida spectacled bear and the giant short-faced bears of the Middle Pleistocene to Late Pleistocene age.

The spectacled bear’s scientific name is Tremarctos ornatus. The root trem comes from a Greek word meaning hole and 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, spectacled bear.

ALTERNATE

Andean Bear, Mountain Bear, Short-Faced Bear

GROUP

Pack, Sleuth, Sloth

MALE

Boar

FEMALE

Sow

YOUNG

Cub

The spectacled bear is the only species of bear native to South America and is known as the Andean Bear because of its range in the Andes Mountains. It is one of the most emblematic mammals of the tropical Andes.

Despite some rare spilling-over into eastern Panama, the spectacled bear is mostly restricted to certain areas of northern and western South America. It can be found throughout mountainous regions of the Andes in Ecuador, Colombia, western Venezuela, Peru, western Bolivia, and might also occur in northwestern Argentina. The species is found almost entirely in the Andes Mountains.

According to some researchers, the greatest number of bears is to be found on the borders between Colombia, Ecuador, and Peru.

EXTANT

Bolivia, Colombia, Ecuador, Peru, Venezuela, Bolivaria

VAGRANT

Argentina

Spectacled bears have a reputation of being adaptable and inhabit a wide variety of habitats throughout their range. It is believed that the bears travel between habitat types depending on the season, but the timing of these migrations and what drives them is unknown.

They are most commonly found in dense cloud, or Andean forests, where there is an abundance of food and shelter. They are also found in high Andean moorland, (páramo’s), dry forests, scrub deserts, and high-altitude grasslands.

The best habitats for spectacled bears are humid to very humid montane forests. Generally, the wetter the forests, the more food species there are that can support bears.

The cloud forests that spectacled bears reside in typically occupy a 500-1,000 meter, (1,600-3,300 feet,) elevational band between 1,000 and 2,700 meters, (3,300 and 8,900 feet,) depending on latitude. Occasionally, Andean bears may reach altitudes as low as 250 meters, (820 feet,) but are not typically found below 1,000 meters, (3,280 feet,) in the foothills. They can even range up to the mountain snow line at over 5,000 meters, (16,000 feet,) in elevation.

FOREST

Subtropical/Tropical Dry, Subtropical/Tropical Moist Lowland, Subtropical/Tropical Moist Montane

SHRUBLAND

Subtropical/Tropical Dry, Subtropical/Tropical Moist, Subtropical/Tropical High Altitude

GRASSLAND

Subtropical/Tropical High Altitude

There is some disagreement over the activity pattern of the spectacled bear. Some argue that they are strictly diurnal and crepuscular, whereas others have stated that they are nocturnal as well. In Andean cloud forests, spectacled bears may be active both during the day and night, but in Peruvian desert, they are reported to bed down under vegetative cover during the day.

There is no evidence to suggest that this species spends any portion of the year hibernating.

Spectacled bears are one of four extant bear species that are habitually arboreal, alongside the American black bear (Ursus americanus), Asian black bear (Ursus thibetanus), and the sun bear, (Helarctos malayanus).

Andean bears are excellent climbers and spend a fair amount of time in trees. Despite their weight, they can even jump from tree to tree without injury. The bears have even been observed climbing out onto the ends of limbs, biting the branches to break them and causing the animal to fall to the branch below, and continuing this process until they reach the ground. Spectacled bears have been reported falling in this manner from heights as high as 30 feet.

One of the more unique features of Andean bears is their construction and use of platforms or nests which the bears create in the understory of the trees. These platforms allow the bear to obtain easier access to food high in the canopy, provide concealment, and are also used for sleeping.

Olfaction is the dominant form of communication for spectacled bears.

Spectacled bears tend to be solitary animals and isolate themselves from one another in order to avoid competition. Exceptions include females with cubs and small gatherings when food is abundant. Andean bears have been reported to gather in small groups to feed in corn fields or other areas where food is plentiful.

Because they have been observed to feed in small groups, it is unlikely that these bears are highly territorial. They are also shy, peaceful, and elusive, avoiding contact with humans.

Some sources report seasonal- and sex-based differences in the home ranges of spectacled bears. Males are reported to have an average home range of 23 square kilometers during the wet season and 27 square kilometers during the dry season. Females are reported to have an average home range of 10 square kilometers in the wet season and 7 square kilometers in the dry season.

CIRCADIAN RHYTHM

Diurnal, Crepuscular, Nocturnal

Like other bears, spectacled bears are omnivorous and will feed upon invertebrates, small mammals, rodents, birds, and insects. They will also readily scavenge from a carcass and feed upon carrion.

Only 5% of the Andean bear’s diet is composed of meat, however, as they are mainly herbivorous folivores and frugivores that feed upon leaves and fruit. Animal prey is usually quite small, but these bears can prey on adult deer, llama (Lama glama) and cattle (Bos taurus) and horses (Equus ferus caballus). A spectacled bear was captured on a remote video-monitor predaceously attacking and killing an adult mountain tapir (Tapirus pinchaque) perhaps nearly twice its own body mass, although adult horse and cattle killed by spectacled bears have been even heavier. Animal prey has included rabbits, mice, other rodents, birds at the nest (especially ground-nesting birds like tinamous or lapwings, such as the southern lapwing (Vanellus chilensis), Andean lapwing (Vanellus resplendens), and the pied lapwing (Hoploxypterus cayanus), arthropods, and carrion.

Besides giant pandas (Ailuropoda melanoleuca), spectacled bears are probably the most herbivorous bear species. They seem to have a strong preference for bromeliads and fruits. When ripe fruit is not available, however, the bears live off fibrous parts of plants, such as moss, cacti, orchid bulbs, bamboo hearts, honey, tree bark, palm petioles, leaves, stems, seeds, grains, corn, maize, nuts, flowers, and bryophytes.

Spectacled bears are the largest land carnivore and second largest terrestrial mammal in South America, after the lowland tapir (Tapirus terrestris).

PREFERENCE

Generalist

STYLE

Forager

Much of the mating behavior of the spectacled bear remains unstudied, but they are believed to be polygynous.

Males and females mainly come together to mate between the months of April and June. The pair remains together for 1 to 2 weeks, copulating several times during this period. Mating pairs of spectacled bears can been seen together between the months of March and October, during the time of year when fruit is beginning to ripen. This indicates that, like bears in captivity, spectacled bears are probably adapted to breeding at various times throughout the year.

Andean bears are monestrous, breeding only once per year, and are probably capable of delayed implantation. This would explain the variation in gestation times in captive bears, 160 to 255 days, and the out of season births observed in wild bears.

The size of a spectacled bear’s litter is positively correlated with the weight of the female and the abundance and variety of food sources. In the wild, one to four cubs are born to a single female. In captivity, a female gives birth to two cubs on average.

Spectacled bear cubs are typically born several months before the fruit season begins between September and February. This allows the cubs sufficient time to be weaned before the fruit ripens for them to eat. The cubs are born blind and their eyes do not open until 30 days, during which time they are completely dependent on their mother. At birth, they weigh about 300 grams each and are black in color, already showing the spectacle markings on the face.

There is no known paternal involvement in the rearing of spectacled bear cubs and adult males may eat any cubs they come into contact with.

At least five distinct vocal communication sounds used between mothers and cubs have been described.

Spectacled bear cubs grow fairly quickly and already weigh 10 kilograms at 180 days. They stay with their mother for up to a year after birth. Both male and female bears reach sexual maturity between the ages of 4 and 7 years.

BREEDING SEASON

March-October

BREEDING INTERVAL

1 Year

COPULATION

12-45 Minutes

PARENTAL INVESTMENT

Maternal

GESTATION

5.5-8.5 Months

BIRTHING SEASON

December-February

LITTER

1-4

WEANING

1 Year

INDEPENDENCE

1 Year

SEXUAL MATURITY

4-7 Years

The role that spectacled bears play in the ecosystem remains largely unstudied. However, because of their largely herbivorous diet, it is likely that they play a role in seed dispersal.

There are no reported predators on adult spectacled bears, but cubs may be preyed on by pumas (Puma concolor), jaguars (Panthera onca), and occasionally by adult male spectacled bears.

Spectacled bears are shy, peaceful, and elusive, and avoid contact with humans. They work hard to avoid human detection and confrontation. There are no verified accounts of fatal bear-human confrontations, at least none in which the person did not survive, as Andean bear attacks are virtually unheard of.

The continued survival of spectacled bears alongside humans has depended mostly on their ability to climb even the tallest trees of the Andes. Unlike other bear species, such as the brown bear (Ursus arctos), Andean bears are not particularly big and are extremely capable climbers, preferring to run from danger and hide in treetops than defend themselves aggressively. When approached by people, they invariably retreat, often by climbing trees. For the bear, safety means getting as far away as quickly as possible-usually by climbing into the thick, tangled canopy.

Spectacled bears have even been observed building platforms of bent and broken branches in trees in order to watch cornfields or herds of cattle (Bos taurus) in order to wait until there is no sign of humans. The bears are quickly able to build the platforms in an attempt to hide from the sight of the humans below. If the humans do not retreat, the bear may break off and throw branches at the intruders. Andean bears will even try to escape by jumping from tree to tree.

Spectacled bears can be persecuted by local farmers who blame them for killing cattle and for destroying maize crops. Often, multiple bears are killed without firm evidence of which was the offending culprit. In areas where farming and cattle-raising have intruded into former Andean bear habitat, reducing the bears’ natural sources of food, the spectacled bears have been known to raid farmers’ crops, especially those of maize and cultivated corn. These incidents often often result in the bears being shot. Spectacled bears have rarely been observed killing livestock and cattle that graze near forest lands. Not natural-born killers, the bears have been observed to simply jump on top of unwary cows and begin chomping on their shoulders. If the cow cannot escape and dies, its carcass may be dragged back into the forest and consumed over several days. Such attacks, though, are rare.

Spectacled bears are sometimes hunted illegally for medicinal or ritual purposes. In some parts of the Andean bear’s range, the meat, skin, fat, and claws are highly prized and in demand locally. In some regions in South America, the bear’s meat is believed to impart strength, its fat is used to cure certain illnesses, and its claws are supposed to bring good luck. The Andean bear’s gallbladder is often sold to the east Asian or international market where it is used for traditional oriental medicinal purposes although there is no proven benefit of these materials for humans and the effect of this illegal hunting on populations can be devastating. Recent estimates put the price at $150.00 USD for one gallbladder, which is five times the average monthly wage in Ecuador.

Spectacled bears possess great religious and cultural value to the native people whom share their range and are the source of a lot of myths. Until humans began to forcibly introduce themselves, wild Andean bears were mysterious and a bit mythological. Some indigenous cultures in South America revered them as spiritual mediators. In some areas, they are considered a divine creature linking Heaven to Earth.

PETS/DISPLAY ANIMALS, HORTICULTURE

National, International

FOOD

Local

MEDICINE

Local

Because spectacled bears are shy and stealthy and live in remote habitats, no one knows exactly how many remain in the wild. Estimates range from a high of 20,000 to as few as 2,400. Recent estimated population sizes for most speculated bear areas are small, with a total estimate for the Northern Andes, (excluding most of Peru, Bolivia, and northern Argentina,) comprised anywhere between 6,000 and 10,000 individuals.

30% of the Andean bear’s habitat has been lost since the 1990s and 3-6% more habitat is lost each year. In Ecuador, alone, there has been an estimated 40% loss of suitable habitat in the bears’ natural range. This creates small isolated island populations of bears. About 30% of the spectacled bear’s habitat has been deemed unsuitable to sustain viable Andean bear populations.

MATURE INDIVIDUALS

2,500-10,000

FRAGMENTATION

Not Fragmented

As with many species, loss of habitat plays a major role in the population decline of spectacled bears. Habitat destruction and fragmentation have been rife in the area that this bear inhabits and are likely to have been major causes of its decline in numbers. Since spectacled bears rely on different habitats to produce their food supply during different seasons, it is essential to preserve large areas to ensure that the bears have a sufficient supply of food throughout the year.

Human development and encroachment, from agriculture to new settlements, into previously inaccessible South American forests has significantly impacted the bear’s numbers throughout its range. Sadly, habitat loss and fragmentation is bringing bears and humans into greater proximity, leading to increased human-bear-conflict. This increase in conflict results in reduced tolerance and escalated bear kills. Thus, even where a habitat patch is of sufficient size to maintain a bear population, human-caused mortality is likely to reduce bear density.

Mining, road development, and oil exploration are also increasing threats to the spectacled bear’s habitat.

AGRICULTURE & AQUACULTURE

Annual & Perennial Non-Timber Crops, Livestock Farming & Ranching

ENERGY PRODUCTION & MINING

Oil & Gas Drilling, Mining & Quarrying

TRANSPORATION & SERVICE CORRIDORS

Roads & Railroads

BIOLOGICAL RESOURCE USE

Hunting & Trapping Terrestrial Animals

CLIMATE CHANGE & SEVERE WEATHER

Habitat Shifting & Alteration, Droughts, Temperature Extremes, Storms & Flooding

A total of 58 protected areas have been established across the spectacled bear’s distribution, but threats remain within their boundaries with most of these areas being no more than Paper Parks lacking adequate budget and staff. Although efforts to establish, maintain, and connect old and new protected areas along the bear’s range have been carried out, such as the Vilcabamba-Amboro corridor between Peru and Bolivia and the interconnected system of protected areas in the Venezuela Andes, large portions of the bear’s habitat are still unprotected and poaching has not been controlled. Between 2007 and 2014, a number of important steps towards spectacled bear conservation have been undertaken across its distribution including promotion of conservation by local education programs and research projects carried out by conservation groups, NGOs, zoological parks, universities, research institutes and government agencies in Bolivia, Peru and Venezuela. National action plans for Venezuela, Colombia, and Ecuador, and a national assessment for Bolivia have been published. Unfortunately priority actions highlighted by some of these programs have not been undertaken. Such is the case for the three key areas identified for connectivity conservation within the Venezuelan Action Plan.

Knowledge regarding the species ecology has improved, with information about home range sizes, movement patterns, and population sizes for some locations in Peru, Ecuador, and Colombia. Nevertheless, in order to develop robust conservation actions, further efforts regarding population sizes and limiting factors are required. Current and future research needs to focus on populations, habitat and connectivity, human dimensions, and climate change effects on both the ecology of the species and human-bear conflict. Finally, it is important to encourage conservation initiatives to focus on a more holistic and creative approach where the needs of the species and the people inhabiting the Andes mountain range are jointly considered.