Shrouded in mystery the Andean or spectacled bear (Tremarctos ornatus) is South Americas only bear species, is largely vegetarian, and is the enigmatic flagship for the atmospheric fairy tale cloud forests or Yungas of the Greater Madidi Landscape. The Andean bear is characterized by a white or light brown stain that covers part of its face, around the eyes often appearing as spectacles, although the form and amount of white or brown is variable. It is a solitary animal, which nests in trees or caves. According to studies conducted in the Madidi region with support from WCS, the Andean bear diet is based mainly on plants of the families of Bromeliaceae (Puya sp.) Ericaceae (Gaultheria vacciniodes, Vaccinium floribundum), Rosaceae (Rubus sp.) and Symplocaceae. This diet is complemented with live or dead animals, especially mammals, birds and insects.
WCS has been supporting Andean bear studies in the Greater Madidi-Tambopata Landscape since 1997 when Susanna Paisley began the first ever radio-telemetry studies on this species at the Pusupunku valley on the border between the Apolobamba and Madidi protected areas. The study confirmed the diurnal habits of Andean bears and also made the first ever estimates of its areas of action, as well as showing long distance movements of up to 15 km in a straight line.
Subsequently in 2000 we began studies using standard survey plots to find out which specific habitats Andean bears prefer based on the frequency of ‘bear signs’ (hairs, scats, scratch marks, trails, footprints, nests, feeding sites) found in each habitat.
Andean bears in the Greater Madidi-Tambopata Landscape prefer upper cloud forest and humid Andean grasslands, as well as elfin or tree-line forest and mid-montane forest. This information has been crucial for modeling Andean bear distribution and designing priority conservation interventions between the Greater Madidi-Tambopata Landscape and the Cotapata protected area in La Paz Department.
The estimated abundance of Andean bears using camera-trapping methods and individual recognition of bears through their distinct facial markings in the Pelechuco region was between 4.4 and 6 individuals per 100 km2. The Andean bear population size in the Greater Madidi-Tambopata Landscape is one of the highest in the continent in terms of protected populations, making this region an important conservation area at a continental level. The estimations made at a binational level, among the protected areas of Bahuaja Sonene in Peru, and Apolobamba, Madidi and Pilon Lajas in Bolivia, resulted in a population estimate of 1,000 individuals. In the “Binational Workshop on the Distribution and Coservation satus of Andean Bear in Bolivia and Peru”, held in Lima in 2008, as a culmination of the consultation process with scientific experts, Andean Bear Conservation units were identified, prioritizing areas for the development of conservation actions for the species. For this purpose, a spatial analysis of these areas was carried out assessing their level of connectivity, the percentage of forest and total area.
Habitat loss and human-animal conflict issues threaten the Andean bear across much of its continental range. WCS has worked with local communities to measure crop losses in cornfields, and also assess perceptions of livestock losses on the Andean humid grasslands adjacent to montane forests. In summary, bears were one of the main culprits of wildlife related crop damage and non-lethal mitigation techniques reduced this loss to virtually nothing. Andean bears are also blamed for almost all livestock losses in the humid valleys although our limited data suggest that their role is greatly exaggerated