Tremarctos ornatus


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Tremarctos ornatus
Species Authority: (F.G. Cuvier, 1825)
Common Name/s:
English Spectacled Bear, Andean Bear
French Ours Andin, Ours à lunettes
Spanish Oso de Anteojos, Oso Frontino, Oso Real

Assessment Information [top]

Red List Category & Criteria: Vulnerable A4cd ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor/s: Goldstein, I., Velez-Liendo, X., Paisley, S. & Garshelis, D.L. (IUCN SSC Bear Specialist Group)
Reviewer/s: McLellan, B.N. & Garshelis, D.L. (Bear Red List Authority)
Contributor/s: The following people assisted with range mapping: Velez-Liendo, X., Amanzo, J., Riveros, J.C., Garcia-Rangel, S. & Secada, L.
It is likely that Andean bear populations will decline by more than 30% within a 30-year window that includes both the past and future. Habitat loss continues at a rate of 2-4% per year, and the level of exploitation is thought to be high in many portions of the range. These threats have not ceased, nor are there any indications that they will diminish in the near future. Even though many protected areas have been established over the past 20 years and more are expected to be added in the next few years, those areas protect only a fraction of the remaining Andean bear habitat. Moreover, even within protected areas, bears are vulnerable to habitat destruction and poaching because many areas are inadequately patrolled. Road development and the advance of agriculture are particularly insidious because they diminish and fragment habitat, and also attract bears, which are killed when depredating crops. Increasing mining and oil exploitation pose additional significant threats to this species.

Based just on trends in human population density (and the deterioration of habitat and increased exploitation of animal populations that this inevitably entails), Cardillo et al. (2004) listed Andean bears among the Carnivores that are most likely to move toward extinction. By 2030, they predict that this species would meet the IUCN criteria for Endangered.
1996 Vulnerable
1994 Vulnerable (Groombridge 1994)
1990 Vulnerable (IUCN 1990)
1988 Vulnerable (IUCN Conservation Monitoring Centre 1988)
1986 Vulnerable (IUCN Conservation Monitoring Centre 1986)
1982 Vulnerable (Thornback and Jenkins 1982)

Geographic Range [top]

Range Description: Endemic to the Tropical Andes, the Andean bear is the only extant species of bear in South America. The northern limit of its range are Sierra de Perijá, Macizo de El Tamá and Cordillera de Mérida in Venezuela; southward it inhabits the Occidental, Central and Oriental Colombian ranges; both eastern and western slopes of the Ecuadorian Andes; all three Andean ranges of Peru, including a portion of the Pacific coastal desert; and the eastern slope of the Andes in Bolivia.

Historical reports include the Panama regions of El Darien (Jorgenson 1984) and Caledonia (Global Biodiversity Information Facility Data Portal 2008) but recent surveys of suspected populations in El Darien (Goldstein et al. 2007), as well as in northern Argentina, have not yielded conclusive evidence of bear presence.
Bolivia, Plurinational States of; Colombia; Ecuador; Peru; Venezuela, Bolivarian Republic of
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: In the late 1990s, a range map was produced and an approximate area of occupancy estimated (260,000 km²). By applying minimum and median density estimates from American black bears (Ursus americanus) to this area, Peyton et al. (1998) generated a rough range-wide population estimate (>20,000 Andean bears). Ruiz-Garcia (2003) attempted to obtain a population estimate by applying mutation rates to current genetic heterozygosity for bears in Venezuela, Colombia and Ecuador (assuming no genetic bottleneck); extrapolating this range-wide yielded a very wide span of estimates (approximately 5,000 to 30,000 breeding bears). Other investigators obtained population estimates from small study areas, using DNA fingerprinting (in a protected area in Ecuador; Viteri and Waits 2005) and camera trapping (in a protected area in Bolivia; Rios-Uzeda et al. 2007), but the sample sizes and area of coverage were too small to extrapolate further. Thus, valid country-wide or range-wide population estimates are still lacking.
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: Andean bears occupy a great variety of habitats, from desert-scrub to forests to high altitude grasslands, ranging in elevation from 250 to 4,750 m asl. They are reported to move along an altitudinal gradient among different habitat types, following seasonal patterns of food resources (Peyton 1980, Suarez 1988, Velez 1999, Paisley 2001, Cuesta et al. 2003). On the slopes of the eastern Andes, bear populations exist from the snowline down to 300 m asl in the Tapo-Caparo National Park in Venezuela, 1,200 m asl in Colombia, 600 m asl in Ecuador and Peru, and 550 m asl in Bolivia; on the western Andes of Peru they range down to 250 m asl (Peyton 1999a, Goldstein 2006)

With the notable exception of the dry forest-scrub habitat in north coastal Peru (Peyton 1999b), Andean bears are most commonly found in high elevation elfin forests, upper montane humid forest, and humid grasslands (Peyton 1987a,b, Velez 1999, Cuesta et al. 2003, Rios-Uzeda et al. 2005). Within this range, habitat preferences are uncertain. In portions of the central Andes in Bolivia, Andean bears were reported to select wet montane / foothill forests at lower elevations (Rumiz et al. 1999); elsewhere in Bolivia they heavily used cloud forests of the upper slopes of the Andes and rarely used dry montane forests (Rios-Uzeda et al. 2005). Bear presence can readily be identified in the high altitude grasslands due to the easier visibility and the durability of the obvious feeding sign, but these grasslands may not sustain bears year-round without access to forest (Suarez 1985, Paisley 2001).

Andean bears are omnivores, feeding mainly on vegetative material such as fruits and succulent plants, and occasionally meat. Common dietary mainstays throughout their distribution are the succulent parts of plants of the families Bromeliaceae and Arecaceae (Peyton 1980, Suarez 1988, Mondolfi 1989). However, food habits change from site to site and even within sites depending on the availability of particular resources. Tree and ground nests are used for resting where Andean bears feed on fruits high in the tree canopy and at sites where bears consume animal (e.g., livestock) carcasses (Goldstein 1991, Velez 1999). Activity patterns range from strictly diurnal for wild bears in Bolivia (Paisley and Garshelis 2006a) to mixed diurnal and nocturnal for reintroduced bears in Ecuador (Castellanos et al. 2005). As food is available year-round in all parts of their range, Andean bears do not hibernate. Based on the first few individuals of this species to be monitored using ground telemetry in Bolivia (Paisley and Garshelis 2006b) and Ecuador (Castellanos 2007 and pers. com. 2008), home ranges overlap to a high degree and minimum home range sizes vary from 10 to 160 km² (although these are underestimates, as the bears were regularly out of range of radiotelemetry in both studies).

Information on reproduction in this species is limited. Litter size is typically two cubs. The timing of births in the wild has rarely been observed, but in captivity birthing varies with latitude (Garshelis 2004). Presumed mating pairs have been observed in the wild during March-October.
Systems: Terrestrial

Threats [top]

Major Threat(s): Habitat loss and fragmentation, poaching, and the lack of knowledge about the distribution and status of the Andean bear are the principal threats to this species (Peyton 1999a, Rodriguez et al. 2003). Much of the range of the Andean bear has been fragmented by human activities, largely resulting from the expansion of the agricultural frontier. In some areas, mining, road development and oil exploitation are becoming a greater menace to Andean bear populations as well as to local communities, due to land expropriation, loss of habitat connectivity, and water and soil contamination (Peyton 1999a, Young and Leon 1999).

Many Andean bear populations are isolated in small to medium-sized patches of intact habitat, particularly in the northern part of the range (Yerena et al. 2003, Kattan et al. 2004). The situation tends to improve towards the southern range, with some large patches of wilderness still remaining (Peyton 1999a). Nevertheless, human population growth and national development plans throughout the Tropical Andes continue to be an important cause of habitat fragmentation and to threaten the connectivity among remaining wilderness patches.

Poaching is a serious threat throughout the Andean bear range. Bears are often killed after damaging crops, particularly maize, or after purportedly killing livestock (Goldstein 1991, Peyton 1999b, Rumiz and Salazar 1999, Suarez 1999, Castellanos 2002, Morales 2003). Also, Andean bear products are used for medicinal or ritual purposes and at some localities Andean bear meat is highly prized (Yerena 1999). Live bears are also sometimes captured and sold (Jorgenson and Sandoval 2005). Human induced mortality endangers the viability of small remnant populations.

Lack of knowledge about the distribution and status is a problem throughout the region. In many areas, information about the status of Andean bears is outdated or, particularly in the southern portion of the range, simply non-existent. The absence of knowledge makes it difficult to develop realistic management plans for the conservation of this species, or to monitor changes in its distribution (reflective of changes in population status).

Conservation Actions [top]

Conservation Actions: In 1998, Peyton et al. reported that <20% (48,000 km²) of the range was legally protected, including 58 national parks, reserves or sanctuaries. Since then, several of the parks have been enlarged and new ones have been established. However, many of these contain habitats that are not adequate, and others are still too small or isolated to sustain viable bear populations, prompting efforts to develop corridors to link groups of protected areas (Yerena 1999, Yerena et al. 2003, Peyton 1999a,b, Jorgenson and Sandoval 2005).

Studies on the distribution, frequency and intensity of Andean bear-human conflicts have been carried out in some areas in order to better understand these situations and thereby develop management measures to reduce conflicts and the consequent killing of bears (Goldstein et al. 2006). Management plans to reduce bear-cattle conflicts have been developed at the Oyacachi, Ecuador, based on predation probability models (Goldstein 2006).

Workshops have been conducted in several of the range countries to train researchers and personnel from national parks on survey techniques, development of habitat models, and general knowledge about the ecology, distribution and status of the species (Goldstein 2006).

Andean bears are listed on Appendix I of CITES and are protected through national legislation in each range country. However, there are loopholes in these laws by which bears can be (and thus frequently are) killed or removed from the wild (Orejuela and Jorgenson 1999, Peyton 1999b, Rumiz and Salazar 1999, Suarez 1999, Yerena 1999, Jorgenson and Sandoval 2005).
Citation: Goldstein, I., Velez-Liendo, X., Paisley, S. & Garshelis, D.L. (IUCN SSC Bear Specialist Group) 2008. Tremarctos ornatus. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <>. Downloaded on 19 April 2014.
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