Tremarctos ornatus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Carnivora Ursidae

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

Assessment Information [top]

Red List Category & Criteria: Vulnerable A3c+4c ver 3.1
Year Published: 2017
Date Assessed: 2016-02-02
Assessor(s): Velez-Liendo, X. & García-Rangel, S.
Reviewer(s): Garshelis, D.L. & McLellan, B.N.
Contributor(s): Viteri Espinel, M., Wallace, R., Rumiz, D.I., Pacheco, L., Lameda, I., Goldstein, I., Bracho, A.E., Zug, R., Amanzo, J., Castellanos, A., Marquez, R., Restrepo, H. & Hidalgo-Hermoso, E.

A landscape assessment of habitat suitability and connectivity carried out for this assessment identified ~30% of habitat as unsuitable to sustain viable Andean Bear populations. Key patches for sustainable populations of Andean Bears were defined as areas larger than 400 km² and within 15 km of the nearest patch (Verboom et al. 2001, Velez-Liendo 2014). At the national level, Venezuela showed the greatest projected loss of key patches (70%), with only two of these key patches available to sustain its bear population. Peru, Colombia and Ecuador are projected to lose 31%, 29% and 27% respectively, and Bolivia 19%. Causes of this loss of key patch habitat is associated with human development activities that have not ceased, and in some areas may increase by allowing oil exploration and exploitation within some protected areas. Expansion of the agricultural frontier, inadequate agricultural practices and land/agrarian reforms; mining and oil exploitation, conversion of land to coca crops and the drug trade, have been the main drivers of the loss and degradation of Andean bear habitat (Ataroff and Rada 2000, Palminteri et al. 2001, Armenteras et al. 2003, 2011; Rodríguez et al. 2003, Kattan et al. 2004, Yerena et al. 2007, Velez-Liendo 2010, Dávalos et al. 2011, García-Rangel 2012, Portillo-Quintero et al. 2012, Sánchez-Mercado et al. 2014). Three main data sources were used to map these human intrusions on Andean Bear habitat: disturbed areas (roads, settlements, agriculture fields, etc.) from Josse et al. (2009), forest cover loss derived from satellite imagery for the period 2000-2013 (Hansen et al. 2013) and 8 years (2000-2008) of fire activities from MODIS Rapid Response System data sets ( (Velez-Liendo 2010; note: data and imagery were from LANCE FIRMS operated by the NASA/GSFC/Earth Science Data and Information System (ESDIS) with funding provided by NASA/HQ).

Furthermore, as a consequence of habitat loss, human-bear conflicts are likely to increase resulting in reduced tolerance and escalating bear kills (Goldstein et al. 2006; Sánchez-Mercado et al. 2008, 2014; García-Rangel 2012; Zukowsky and Ormsby 2016). Thus, even where a habitat patch is of sufficient size to maintain a bear population, human-caused mortality is likely to reduce bear density.

Climate change projections for 2010-2039 by Tovar et al. (2013) indicate that all ecosystems inhabited by Andean Bears will exhibit a degree of loss: 30% loss for Tropical high altitude grasslands, 24% for Tropical dry and moist shrublands, and 18% for Tropical moist lowland and montane forests. Based on the current state of the Andean Bear’s habitat, the fact that many threats causing reduction and degradation of Andean Bear ecosystems have not ceased, and projected patterns of biodiversity shift caused by climate change, the species is vulnerable to widespread future decline.

Andean Bear species’ experts in the Bear Specialist Group considered all of these threats and provided estimates of rates of decline.  Experts estimated rates of decline of >30% for each of the five range countries in the next 30 years and also in a 30-year time window overlapping the present (2000–2030). This qualifies the species for Vulnerable, under criteria A3 and A4. There is also a reasonable likelihood that the global population consists of <10,000 mature adults (given a total population of <20,000 bears), a condition under criteria C1, but since the rate of future population decline is only suspected based on rates of habitat loss or alteration, the nature of the evidence is insufficient (i.e., not directly estimated) to categorize the species under C1.

Previously published Red List assessments:

Geographic Range [top]

Range Description:

The Andean Bear is the only extant bear species in South America and is endemic to the Tropical Andes (Kattan et al. 2004; Ríos-Uzeda et al. 2006, 2007; Viteri 2007; Viteri and Waits 2009; García-Rangel 2012). The distribution of this species is long (ca 4,600 km) and narrow (ca 200-650 km) in the mountains from Venezuela to Bolivia (Peyton et al. 1998, Yerena 1998, Peyton 1999, Rodríguez et al. 2003, Kattan et al. 2004). From North to South, Andean bears are found in Sierra de Perijá and Cordillera de Mérida in Venezuela; the Occidental, Central, and Oriental Andean mountain ranges of Colombia; both Eastern and Western slopes of the Ecuadorian Andes; across the three Peruvian Andean mountain ranges, including a portion of the North Pacific coastal desert; and in the Eastern slope of the Tropical Andes in Bolivia (García-Rangel 2012). The possible presence of the bear in Panama was reported by Hershkovitz (1957), but recent surveys in the area did not find evidence to support this claim (Goldstein et al. 2008). Recently, presence of Andean bears in Northern Argentina has been confirmed by Cosse et al. (2014) through genetics. However, given that these presence points are up to 300 km south (straight line) of the known most-southerly population in Bolivia, they may represent vagrant individuals rather than resident populations.

Countries occurrence:
Bolivia, Plurinational States of; Colombia; Ecuador; Peru; Venezuela, Bolivarian Republic of
Additional data:
Lower elevation limit (metres):200
Upper elevation limit (metres):4750
Range Map:Click here to open the map viewer and explore range.

Population [top]


Expert knowledge, data extrapolations, genetic analysis, mark-recapture, radio tracking and sign surveys, as well as ecological modelling have been used to estimate population sizes and densities of Andean Bears (Peyton 1984, 1999; Yerena 1994; Peyton et al. 1998; Cuesta and Suárez 2001; Ruiz-García 2003; Kattan et al. 2004; Viteri 2007; Ríos-Uzeda et al. 2007; Velez-Liendo 2010; Garshelis 2011; García-Rangel 2012). Wild populations are believed to be on decline due to habitat loss and fragmentation, and illegal killing (Rodríguez et al. 2003, Kattan et al. 2004, Yerena et al. 2007, Sánchez-Mercado et al. 2008, Velez-Liendo et al. 2009, Velez-Liendo and Paisley 2010, García-Rangel 2012). National assessments applying different approaches estimated 1,100-1,600 bears in Venezuela (Ruiz-García 2003), 3,000-6,000 in Colombia (Ruiz-García 2003), 1,200-2,000 in Ecuador (Cuesta and Suárez 2001, Viteri 2007), ~5,000 bears in Peru (Peyton 1999), and ~3,000 bears in Bolivia (Velez-Liendo 2010). These rather crude countrywide estimates, yielding a range-wide estimate of 13,000-18,000 bears (5-7 bears/100 km² over its 260,000 km² range), are reasonably consistent with three empirically-derived mark-recapture (re-sight) density estimates of 3-8 bears/100 km² (Viteri 2007, Ríos-Uzeda et al. 2007, S. Molina, pers. comm). It should be cautioned, however, that all abundance and density estimates for this species have known biases, so consistency among the estimates is not verification of their accuracy (Garshelis 2011).

Current Population Trend:Decreasing
Additional data:
Number of mature individuals:2500-10000Continuing decline of mature individuals:Unknown
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:

Andean Bear altitudinal range extends from 200 to 4,750 m above sea level, with an area of occupancy covering approximately 260,000 km² along the Tropical Andes. The lower limit is on the Western Peruvian range; the upper limit is within Carrasco National Park in Bolivia (Peyton 1980, 1984, 1999; Goldstein 1990, Rodríguez-Rodríguez and Cadena 1991, Rodríguez et al. 2003, Sánchez-Mercado 2008, Figueroa and Stucchi 2009, Velez-Liendo 2010, García-Rangel 2012, Appleton et al. 2013).

The species inhabits a great variety of ecosystems along the Tropical Andes including Tropical dry forests, Tropical moist lowland and montane forests; Tropical dry and moist shrublands, and Tropical high altitude shrubland and grasslands (García-Rangel 2012). Seasonal shifts in habitat use due to changes in food availability have been reported (Peyton 1980, Rodríguez-Rodríguez and Cadena 1991, Velez-Liendo 1999, Paisley 2001, Cuesta et al. 2003, Troya et al. 2004, Ríos-Uzeda et al. 2006, Figueroa and Stucchi 2009). Andean bears are mostly found in Tropical moist forests and Tropical high-altitude grasslands (Peyton 1980, 1987a, 1987b, 1999; Velez-Liendo 1999, Cuesta et al. 2003, Ríos-Uzeda et al. 2006, Sánchez-Mercado 2008), but it remains unclear whether bears can live entirely in high-altitude grasslands and paramo without access to forested areas (Paisley and Garshelis 2006). In the north coast of Peru, Andean bears inhabit a Tropical dry shrubland (Peyton 1999, Figueroa and Stucchi 2009, García-Rangel 2012, Appleton et al. 2013).

Andean bears are omnivorous and have a suite of physical adaptations for this life style (McLellan and Reiner 1994, Sacco and Van Valkenburgh 2004, Christiansen and Wroe 2007, Christiansen 2008). Anatomical skull and dentition adaptations to grind (Christiansen 2008) and a pseudo-thumb (Salesa et al. 2006) to aid in consuming a diet of fibrous, hard vegetative matter. Andean bears also opportunistically prey on mammals, including rabbits and mountain tapirs (Castellanos 2011a), but most notably free-ranging domestic cattle (Goldstein 1990, 2002; Rodríguez-Rodríguez and Cadena 1991; Peyton 1999; Cuesta and Suárez 2001; Sacco and Van Valkenburgh 2004; Goldstein et al. 2006; Christiansen and Wroe 2007; Christiansen 2008; Torres 2008; Figueroa and Stucchi 2009; García-Rangel 2012). Bromeliads and palm trees constitute the most common food items in the diet of Andean Bears across the majority of their range (Peyton 1980, Goldstein 1990, Rodríguez-Rodríguez and Cadena 1991, Goldstein and Salas 1993, Troya et al. 2004, Rivadeneria-Canedo 2008, Figueroa and Stucchi 2009, Ríos-Uzeda et al. 2009, García-Rangel 2012). On a seasonal basis, fruits are key food sources for the species as they provide carbohydrates, protein and fat necessary to balance their diet (Peyton 1980, 1984, Goldstein 1990, Rodríguez-Rodríguez and Cadena 1991, Rivadeneira-Canedo 2001, Troya et al. 2004, Kattan et al. 2004, Figueroa and Stucchi 2009, Ríos-Uzeda et al. 2009).

Andean Bears are excellent climbers and commonly build tree platforms where they rest, feed on fruits and carcasses, as well as guard feeding areas (Peyton 1980, 1984; Goldstein 1990, 1991, 2002; Torres 2008, García-Rangel 2012). Activity patterns are mainly diurnal, but they vary seasonally and between geographic areas (Paisley 2001, Paisley and Garshelis 2006, Castellanos 2011b). As food is available all year-round in most parts of their range, Andean bears do not hibernate (Peyton 1999, Garshelis 2009). Information on reproduction is limited for Andean Bears and has mainly come from captive individuals (Bloxam 1977, Rosenthal 1988, Claro-Hergueta et al. 2007, Spady et al. 2007, García-Rangel 2012, Enciso and Guimarães 2013).

The species is polyestrous, a facultative seasonal breeder and experiences delayed implantation (Claro-Hergueta et al. 2007, Spady et al. 2007). In captivity, females show three to four oestrous cycles during a single breeding season with no seasonal ovarian activity (Enciso and Guimarães 2013). Mating has been recorded in the wild at various times of year but peaking between March and October (Peyton 1980, Peyton et al. 1998). Litter size varies from one to four, with twins being most common, and may be related to female weight and hence food abundance (Saporiti 1949, Bloxam 1977, Peyton 1980, Claro-Hergueta et al. 2007, García-Rangel 2012). Field observations in Bolivia (Velez-Liendo 1999) suggested that births occur two to three months before the peak of the fruit season, perhaps to allow mothers to leave the den with their cubs when fruits are abundant (Peyton 1980, Peyton et al. 1998, Velez-Liendo 1999, Velez-Liendo and Paisley 2010). In captivity, time of birth varies with latitude but births usually occur from February to September (Garshelis 2004, Claro-Hergueta et al. 2007).

Generation Length (years):10

Use and Trade [top]

Use and Trade:

Some bears are killed for cultural and medical purposes. The extent of commercial trade is unknown but likely limited.

Threats [top]

Major Threat(s):

Habitat Loss
The Tropical Andes has been home to human communities, including the great Inca Empire, for thousands of years and, as a consequence, 90% of Andean ecosystems have been transformed in some way (Young 1998, 2009; Vina and Cavelier 1999; Ataroff and Rada 2000; Myers et al. 2000; Kattan et al. 2004; Armenteras et al. 2011). The expansion of the agricultural frontier, together with inadequate agricultural practices and land/agrarian reforms, have been the main drivers of the loss of natural ecosystems (Peyton et al. 1998, Yerena 1998, Young 1998, Vina and Cavelier 1999, Ataroff and Rada 2000, Armenteras et al. 2011, Portillo-Quintero et al. 2012). Mining and oil exploitation are becoming an increasing menace not only to bears, but to local communities due to land expropriation, loss of habitat connectivity, and contamination of water and soil (Young and León 1999, Bury 2002, Bebbington et al. 2008, Bebbington 2009). Conversion of land to coca crops and the drug trade, together with guerrilla groups in some parts of the Andes, favours a lawless land-use system that also impacts the quality of Andean Bear habitats and the bear's probability of long-term survival (Rodríguez et al. 2003, Yerena et al. 2007, Dávalos et al. 2011, García-Rangel 2012).

Illegal Killing
Illegal killing is an important, but underestimated threat for Andean Bears. Based on a review of the literature, an average of about 180 bears are known to be killed per year across its range—it is suspected that the real number is much higher, and is likely increasing. For example, recent assessments in northern Ecuador showed unprecedented numbers of cattle killed by bears (at least 320 during the period 2009-2014; Zukowski and Ormsby 2016), as more people are turning to dairy cow farming as a livelihood (Jampel 2016). Bears are killed for retaliation against crop or livestock depredations (or protection against future depredations), for cultural or medical beliefs, and for commercial trade (Orejuela and Jorgenson 1999, Peyton 1999, Rumiz and Salazar 1999, Rodríguez et al. 2003, Yerena et al. 2007, Figueroa 2008, Figueroa and Stucchi 2009, Lameda 2011, E.D. Rodríguez pers. comm. 2014, M.P. Viteri pers. comm. 2014). Since the number of bears killed is likely underestimated by a wide margin, the effects of such killing on bear populations is hard to assess, but rates of killing are high in some areas. Sanchez-Mercado et al. (2008, 2014) estimated that up to 36% of the bear’s distribution in the Cordillera de Merida in Venezuela was within an “ecological trap”, due to human threats. These authors estimated that the effects of this threat combined with habitat fragmentation could be fostering an extinction probability higher than 50% over the next 50 years across this mountain range. Bears are killed during opportunistic encounters, while sport hunting, or as retaliation after damaging crops, particularly maize, or killing livestock (Goldstein 1991, 2002; Peyton 1999, Poveda 1999, Morales Vargas 2003, Goldstein et al. 2006, Sánchez-Mercado et al. 2008, Torres 2008).

Climate Change
Global projections of effects of climate change show a general tendency towards upslope displacement of the mountain biome, suggesting that the Tropical Andes is among the most vulnerable region to climate change (Malcom et al. 2006, Urrutia and Vuille 2009, Beaumont et al. 2011). However, the heterogeneity of this hotspot shows a more complex response (Tovar et al. 2013) affecting phenological patterns and increasing species vulnerability with predictions of species loss ranging from 20-50% due to range contractions for many taxa (Cuesta-Camacho et al. 2008, Lawler et al. 2009, Aguirre et al. 2011, Graham et al. 2011, Hoffmann and Sgrò 2011, Chen et al. 2011, Velásquez-Tibatá et al. 2013, Richardson et al. 2013, Pacifici et al. 2015).

It is likely that all ecosystems associated with Andean Bears will exhibit reductions in their extension. With an increment of +0.74 C in the last century, and a projected increase of 4.3 +/- 0.7 C by 2100 (IPCC 2013), extensive changes in habitat are expected: the Tropical high altitude grasslands is the most fragile ecosystem, with an estimated loss of 30% (Tovar et al. 2013) due to the lack of upslope area for migration. Projected reduction in annual rainfall (IPCC 2013) is likely to affect species highly dependent on humidity such as epiphytic bromeliads (Colwell et al. 2008, Svenning and Condit, 2008, Tewsksbury et al. 2008). Tropical dry and moist shrublands are likely to lose 24% of their area (Tovar et al. 2013), mainly due to a significant variation in the number of dry months (IPCC 2013), while a loss of 18% in area was estimated for Tropical moist lowland and montane forests and Tropical dry forests due to upslope displacements. Furthermore, the extensive (and intensive) land use by human activities in Paramo grasslands, are likely to encroach even further, affecting not only the biodiversity associated to this ecosystem, but also the ecosystem services this biome provides to the region.

Changes in climate regimes must therefore be considered as a growing threat for Andean Bears, as they are likely to alter habitat quality as well as land-use patterns, and increase the probability of human–bear encounters and conflict (Karanth and Chellam 2009, Aguirre et al. 2011, Hoffmann and Sgrò 2011, Chen et al. 2011, Sheridan and Bickford 2011, Mysterud 2013, Ripple et al. 2014). Even more, the areas considered to be most vulnerable to climate change across the Andes are those considered important for Andean bears including: Yanachaga Chemillen National Park (NP) (Peru), Manu NP (Peru), Madidi NP (Bolivia), Apolobamba ANMI (Bolivia), Carrasco NP (Bolivia) and Amboro NP (Bolivia) (Hoffman et al. 2011).

Conservation Actions [top]

Conservation Actions:

The Andean Bear has been listed as Vulnerable by the IUCN since 1982 and has been included in CITES Appendix I since 1975. A total of 58 protected areas have been established across the Andean Bear distribution, but threats remain within their boundaries with most of these areas being no more than “Paper Parks” lacking adequate budget and staff (Hardner 2008; Sánchez-Mercado et al. 2008; Monsalve Dam et al. 2010; García-Rangel 2011, 2012). Although efforts to establish, maintain and connect old and new protected areas along the bear’s range have been carried out (e.g., 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 (Yerena 1994, 1998;Yerena et al. 2003, Kattan et al. 2004, Surkin et al. 2010, Yerena and García-Rangel 2010, Hoffman et al. 2011, Sánchez-Mercado et al. 2014). Recently (2007-2014), a number of important steps towards Andean Bear conservation have been undertaken across its distribution including: (1) promotion of Andean Bear conservation by local education programmes and research projects carried out by conservation groups, NGOs, zoological parks, universities, research institutes and government agencies in Bolivia, Peru and Venezuela (Figueroa and Stucchi 2009, Albarracín 2010, García-Rangel 2012). (2) The publication of national action plans for Venezuela, Colombia and Ecuador (Sánchez-Mercado 2008, Castellanos et al. 2010, Monsalve Dam et al. 2010), and a national assessment for Bolivia (Velez-Liendo, et al. 2009). 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 (Yerena et al. 2007).

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 (Rodríguez et al. 2003, Monsalve Dam et al. 2010, Sánchez-Mercado et al. 2010, García-Rangel 2012). Nevertheless, in order to develop robust conservation actions, further efforts regarding population sizes and limiting factors are required. Current and future research need to focus on populations, habitat and connectivity, human dimensions, and climate change effects on both the ecology of the species and human-bear conflict (Rodríguez et al. 2003, Jorgenson and Sandoval 2005, Yerena et al. 2007, Monsalve Dam et al. 2010, Velez-Liendo and Paisley 2010, García-Rangel 2012). 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 (García-Rangel 2012).

Citation: Velez-Liendo, X. & García-Rangel, S. 2017. Tremarctos ornatus. The IUCN Red List of Threatened Species 2017: e.T22066A45034047. . Downloaded on 23 January 2018.
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