Tremarctos ornatusspectacled bear

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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). (Hunter, 2011; Nowak, 1999)

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. (Kattan, et al., 2004; Servheen, et al., 1999)

  • Range elevation
    475 to 3,658 m
    1558.40 to ft
  • Average elevation
    1900-2350 m
    ft

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. (Kattan, et al., 2004; Nowak, 1999; Servheen, et al., 1999)

  • Sexual Dimorphism
  • male larger
  • Range mass
    60 to 200 kg
    132.16 to 440.53 lb
  • Range length
    1.3 to 2.0 m
    4.27 to 6.56 ft

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. ("International Association for Bear Research and Management", 1999)

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. ("International Association for Bear Research and Management", 1999; Hunter, 2011; Nowak, 1999; Servheen, et al., 1999)

  • Breeding interval
    Spectacled bears breed once a year
  • Breeding season
    Spectacled bears breed between March and October.
  • Range number of offspring
    1 to 4
  • Average number of offspring
    2
  • Average number of offspring
    1.5
    AnAge
  • Range gestation period
    5.5 to 8.5 months
  • Average time to independence
    1 years
  • Range age at sexual or reproductive maturity (female)
    4 to 7 years
  • Range age at sexual or reproductive maturity (male)
    4 to 7 years

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. (Nowak, 1999)

  • Parental Investment
  • altricial
  • 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. (Nowak, 1999; Paisley, 2008)

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. (Castellanos, 2011; Nowak, 1999; Servheen, et al., 1999)

  • Range territory size
    7 to 27 km^2

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. (Hunter, 2011)

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. (Nowak, 1999; Servheen, et al., 1999)

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. (Hunter, 2011; Nowak, 1999; Servheen, et al., 1999)

  • Animal Foods
  • birds
  • mammals
  • 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. (Nowak, 1999)

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. (Paisley, 2008; Ruiz-Garcia, et al., 2006; Servheen, et al., 1999)

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. (Nowak, 1999; Servheen, et al., 1999)

  • 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. (Peralvo, et al., 2005)

Contributors

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

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carrion

flesh of dead animals.

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

delayed implantation

in mammals, a condition in which a fertilized egg reaches the uterus but delays its implantation in the uterine lining, sometimes for several months.

diurnal
  1. active during the day, 2. lasting for one day.
ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

migratory

makes seasonal movements between breeding and wintering grounds

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

polygynous

having more than one female as a mate at one time

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

tactile

uses touch to communicate

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

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.

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
. Oryx, 38: 155-163. Accessed March 15, 2012 at http://journals.cambridge.org.proxy1.cl.msu.edu/action/displayAbstract?fromPage=online&aid=220197.

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.