Tremarctos ornatus

Geographic Range

Tremarctos ornatus is the only species of bear native to South America. It can be found throughout mountainous regions of the Andes in Ecuador, Colombia, Venezuela, Peru, Bolivia, and might also occur in northwestern Argentina and into Panama (Hunter, 2011).

• Biogeographic Regions
• neotropical neotropical
  • native native

Habitat

Spectacled bears inhabit a wide variety of habitats throughout their range. They are most commonly found in dense cloud forests where there is an abundance of food and shelter. They are also found in paramo, scrub forest and grasslands. It is believed that these bears travel between habitat types depending on the season, but the timing of these migrations and what drives them is unknown. They are found from 475 to 3658 meters elevation, mostly between 1900 and 2350 meters.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• savanna or grassland savanna or grassland
• forest forest
• rainforest rainforest
• scrub forest scrub forest
• mountains mountains

Physical Description

Spectacled bears are medium sized bears that are typically uniformly black in color, but reddish-brown individuals have been observed. The common name "spectacled bears" comes from the white 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 coat is of medium to long length. Spectacled bears have a short tail, about 70mm long, that is often completely hidden by the fur. They have a stocky build, small round ears, a thick short neck, and a stout muzzle. Like all bears, spectacled bears are equipped with a plantigrade stance and the front limbs are longer than their hind limbs. This feature of the limbs gives most bears amazing climbing abilities. 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.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger

Reproduction

Much of the mating behavior of this species remains unstudied. Males and females 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 System
• polygynous polygynous

Mating pairs of spectacled bears have been seen together between 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. Spectacled bears are monestrous 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. Cubs are typically born several months before the fruit season begins, this allows the cubs sufficient time to be weaned before the fruit ripens for them to eat. In the wild, 1 to 4 cubs are born to a single female. The cubs are born with their eyes closed and weigh about 300 g each. The size of the litter is positively correlated with the weight of the female and the abundance and variety of food sources. In captive bears, a female gives birth to two cubs on average. Both male and female bears reach sexual maturity between the ages of 4 and 6.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• viviparous viviparous
• delayed implantation delayed implantation

Spectacled bear cubs stay with their mother for up to a year after birth. The cubs are born blind and their eyes do not open until 30 days, during which time they are completely dependent on their mother. There is no known paternal involvement in the rearing of the cubs and males may eat any cubs they come into contact with.

• Parental Investment
• altricial altricial
• female parental care female parental care
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female
• pre-independence
  • provisioning
    • female
  • protecting
    • female
• extended period of juvenile learning

Lifespan/Longevity

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

Behavior

Spectacled bears tend to be solitary animals (except when a female is with cubs) but they have been reported to gather in areas where food is abundant. There is some disagreement over their activity pattern. Some argue that they are strictly diurnal and crepuscular, whereas others have stated that they are nocturnal as well. There is no evidence to suggest that this species spends any portion of the year hibernating. These bears are excellent climbers and spend a fair amount of time in trees. One of the more unique features of spectacled bears is their use of platforms or "nests" which the bears create in the understory of the trees that they browse in for fruit. These platforms are also used for sleeping.

• Key Behaviors
• arboreal arboreal
• scansorial
• terricolous
• diurnal diurnal
• nocturnal nocturnal
• crepuscular crepuscular
• motile motile
• migratory migratory
• solitary solitary

Home Range

It is unlikely that these bears are highly territorial, as they have been observed feeding in small groups where food is abundant. 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.

Communication and Perception

Olfaction is the dominant form of communication for spectacled bears. At least five distinct vocal communication sounds used between mothers and cubs have been described.

• Communication Channels
• visual visual
• acoustic acoustic
• chemical chemical

• Perception Channels
• visual visual
• tactile tactile
• chemical chemical

Food Habits

Besides giant pandas , spectacled bears are probably the most herbivorous bear species. They seem to have a strong preference for bromeliads and fruits, but have also been observed eating moss, cacti, orchids, bamboo, honey, tree wood, palms, invertebrates, small mammals, birds, and insects. Spectacled bears have been known to raid farmers crops, especially maize, which often results in the bears being shot. They have rarely been observed killing livestock and will readily scavenge from a carcass. One of their more unique feeding techniques is the construction and use of feeding platforms to obtain easier access to food high in the canopy.

• Primary Diet
• herbivore herbivore
  • folivore folivore
  • frugivore frugivore

• Animal Foods
• birds
• mammals
• carrion carrion
• insects

• Plant Foods
• leaves
• wood, bark, or stems
• seeds, grains, and nuts
• fruit
• flowers
• bryophytes

Predation

Spectacled bears are one of the largest mammals in South America and there are no reported predators on adult bears. Spectacled bear cubs may be preyed on by mountain lions , jaguars , and occasionally by adult male spectacled bears.

Ecosystem Roles

The roll 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.

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

Spectacled bears possess great religious and cultural value to the native people who share their range. Spectacled bears are sometimes hunted illegally for medicinal or ritual purposes. In some parts of their range the meat is highly prized. The gallbladder is often sold to the east Asian market, where it is used for traditional 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.

• Positive Impacts
• food food
• ecotourism ecotourism

Economic Importance for Humans: Negative

Spectacled bears may gather in small groups to feed in corn fields. They may rarely steal livestock from local farms that are encroaching on their habitat.

• Negative Impacts
• crop pest

Conservation Status

As with many species, loss of habitat plays a major role in the population decline of spectacled bears. 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. 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.

Additional Links

Encyclopedia of Life

Contributors

Kesley Fenner (author), Michigan State University, Barbara Lundrigan (editor), Michigan State University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

Castellanos, A. 2011. Andean bear home ranges in the Intag region, Ecuador. Ursus , 22: 65-73.

Hunter, L. 2011. Carnivores of the World . New Jersey, USA: Princeton University Press.

Kattan, G., H. Hernández, I. Goldstein, V. Rojas, O. Murillo, C. Gómez, . Restrepo, F. Cuesta. 2004.

Range fragmentation in the spectacled bear Tremarctos ornatus in the northern Ande

Nowak, R. 1999. Walker's Mammals of the World . Baltimore, MD: Johns Hopkins University Press.

Paisley, S. 2008. "IUCN" (On-line). Accessed March 14, 2012 at http://www.iucnredlist.org/apps/redlist/details/22066/0 .

Parker, E. 2012. "Spectacled Bear - Ecology and Habitat" (On-line). Accessed March 15, 2012 at http://wwf.panda.org/about_our_earth/species/profiles/mammals/spectacled_bear/specbear_ecology_habitat/ .

Peralvo, M., F. Cuesta, F. van Manen. 2005. Delineating Priority Habitat Areas for the Conservation of Andean Bears in Northern Ecuador. Ursidae , 16: 222-233.

Ruiz-Garcia, B., H. Gómez, R. Wallace. 2006. Habitat preferences of the Andean bear (Tremarctos ornatus) in the Bolivian Andes. Journal of Zoology , 268: 271-278.

Servheen, C., S. Herrero, B. Peyton. 1999. Bears. Status Survey and Conservation Action Plan . Gland, Switzerland and Cambridge, UK: IUCN.

2012. "ARKive" (On-line). Accessed March 14, 2012 at http://www.arkive.org/spectacled-bear/tremarctos-ornatus/#text=Biology .

1999. "International Association for Bear Research and Management" (On-line). Bear Species Descriptions. Accessed April 16, 2012 at http://www.bearbiology.com/index.php?id=42 .