Tremarctos ornatus (Cuvier, 1825)

Don E. Wilson & Russell A. Mittermeier, 2009, Ursidae, Handbook of the Mammals of the World – Volume 1 Carnivores, Barcelona: Lynx Edicions, pp. 448-497 : 488

2.

Andean Bear

Tremarctos ornatus

French: Ours a lunettes / German: Brillenbar / Spanish: Oso de anteojos

Other common names: Spectacled Bear, Ucumari

Taxonomy. Ursus ornatus Cuvier, 1825 ,

type specimen purportedly from northern Chile, but the species does not occur there.

No subspecies have been designated, but substantial variation exists in color patterns within different portions of the range. Recent genetic examination in the northern part of the range indicates that gene flow is extremely low (populations are isolated), and that this situation predates the invasion of Europeans (i.e. it is not human-caused). Monotypic.

Distribution. Andes Mountains of Venezuela, Colombia, Ecuador, Peru and Boliva, with controversial evidence of existence in N Argentina.

Descriptive notes. Head-body 130-190 cm, tail less than 10 cm; weight of males 100-175 kg (rarely to 200 kg), females 60-80 kg. Coatis black or sometimes dark brown with creamy white biblike marking on chin, neck, and/or chest and typically some white markings around the muzzle and eyes. The extent of white markings is highly variable. Individuals with complete white circles around both eyes gave rise to the common name Spectacled Bear. However, many if not most do not have complete circles around both eyes; some have partial circles, some are highly asymmetrical, and some have virtually no facial markings or, conversely, an almost all buff-white face. The muzzle is variably-colored and short compared to the ursine bears. Claws are short on both front and rear feet. The underside of the feet have hair between the digital and plantar pads, but not between the plantar and carpal front pads (similar to Asiatic Black Bears).

Habitat. Andean Bears range in elevation from 200 to over 4700 m. Preferred habitat includes various sorts of humid and very humid montane cloud forest. They also occupy higher elevation elfin forest, and puna and paramo (high-altitude) grasslands, as well as lower elevation thorn forest and scrub desert (in western Peru).

Food and Feeding. Omnivorous diet includes many kinds of fruits, vegetative material, and meat. Especially important through most parts of the range are the succulent parts of plants in the family Bromeliaceae , both epiphytic and terrestrial bromeliads. In high altitude grasslands, the heart of the terrestrial Puya is a dietary mainstay, as this bromeliad is the only abundant food available for much of the year. The bears must strip away the stiff thorny leaves to get to the heart, which looks somewhat like a pineapple but is vegetative and bland. Bears may eat only one in ten of this obiquitous plant, possibly related to differences in nutritional composition. In the forest, they regularly climb trees to obtain Tillandsia , an epiphytic bromeliad; they eat the basal meristematic tissue and drop the remaining pieces of leaves to the forest floor, providing a highly visible sign of their feeding activity. Bears select patches (with Puya ) or trees (with Tillandsia ) that have a high density of large bromeliads. Bromeliads compose from 90% to less than 15% of their diet, depending on season and geographic area. Fruits compose the other core part of the diet, varying inversely to the bromeliads. Both shrub and tree-borne fruits are consumed (e.g. Lauraceae , Moraceae , Ericaceae , Euphorbiaceae ). Fruit abundance varies seasonally with rainfall. Other foods include palm petioles, bamboo shoots, bulbs of orchids, and in drier habitats, fruits and pulp of cacti and, remarkably, the soft cortex of the pasallo tree (Bombax discolor). Near human settlements, they routinely raid cornfields. Animal matter is another potentially important food, although never a large dietary component. They eat insects, snails, and small mammals, but more significantly in terms of total nutrition, they occasionally take large mammals such as deer and free-ranging or unguarded pastured cattle. Considerable controversy has surrounded the issue of whether most meat in their diet is from animals that they killed or scavenged—there is clear evidence that they sometimes prey on cattle, but they probably also find carrion. A test of their attraction to beef demonstrated this: a small (0-5 kg) chunk of meat placed in an open area attracted two different radio-collared bears from a distance of 1-5 km in 5-15 hours. When feeding on a cattle carcass, which may take several days to consume, they often construct ground and tree nests for resting. Tree nests are made from a collection of bent and broken branches. They also sometimes build nests in fruit trees.

Activity patterns. In one high-elevation site in Bolivia, composed of mixed grassland and cloud forest, Andean Bears were entirely diurnal. They slept 9-12 hours at night, awoke near sunrise, took brief rests during the day, and began their night's rest just after sunset. This pattern did not vary seasonally. In other areas, bears are reported to be somewhat more active at night, but are still principally diurnal. Because food is available year-round throughout their range, Andean Bears do not hibernate.

Movements, Home range and Social organization. Limited information indicates that home ranges may be as small as 10 km? or as large as 150 km ®. Males have larger ranges than females, and ranges within and between sexes broadly overlap. They are reported to move along an altitudinal gradient among different habitat types, following seasonal changes in available food resources. Andean Bears may gather at rich feeding areas (e.g. cornfields and cactus groves) and at waterholes in arid environments.

Breeding. Presumed mating pairs have been seen between March and October; however, no real information is available on the normal timing of breeding of wild Andean Bears. In captivity in the Northern Hemisphere, births occur from December through February, coinciding with the timing of births in northern species of bears. However, in zoos in South America, Andean Bear births tend to occur more regularly during May-October. Anecdotal information on probable birthing dates in the wild is equivocal. Gestation periods in captivity range from 5-5-8-5 months, indicating a variable period of delayed implantation, and litter size is most commonly two. Litters in the wild are commonly one or two (but up to three or four). Females can produce cubs at two-year intervals, beginning at 4-7 years of age.

Status and Conservation. CITES Appendix I. Listed as Vulnerable on The IUCN Red List. Andean Bears are also protected by national legislation in each of the five range countries. However, loopholes in these laws and lack of adequate enforcement result in bears being killed while depredating crops or livestock, or poached for their parts. Andean Bear products are used for medicinal or ritual purposes, and live bears are also sometimes captured and sold. These problems are exacerbated by habitat loss and fragmentation, which not only reduces their natural foraging area, but also puts the bears in closer proximity to people, crops, and livestock. In a few select areas, management plans have been established, with community involvement, to ameliorate bear-human conflicts. A survey in 1998 revealed that less than 20% of the range was legally protected as parks, reserves or sanctuaries. Since then, additional protected areas have been created and others enlarged, but at the same time, more forested land outside the protected areas has been lost to agriculture or fragmented by road development, and mining activities. Some conservation organizations are working to maintain or establish corridors among populations, especially in the northern part of the range, where many Andean Bear populations are isolated in small to mediumsized patches. Habitat patches are larger in the southern part of the range ( Peru, Bolivia). Valid rangewide or country-wide population estimates are lacking; guesstimates range from about 13,000-25,000. Efforts are underway to survey various parts of the range to obtain information on presence-absence and relative abundance, based on incidence of sign (bear trails, climbed or rubbed trees, tree nests, bed sites, feeding remains, scats).

Bibliography. Cuesta et al. (2003), Garshelis (2004), Goldstein (2002, 2004), Goldstein, Paisley et al. (2006), Goldstein, Velez-Liendo et al. (2007), Jorgenson & Sandoval (2005), Kattan et al. (2004), Mondolfi (1983, 1989), Paisley (2001), Paisley & Garshelis (2006), Peralvo et al. (2005), Peyton (1980, 1987), Peyton et al. (1998), Rodriguez-Clark & Sanchez-Mercado (2006), Ruiz-Garcia (2003), Troya et al. (2004).

Figures

1. Giant Panda (Ailuropoda melanoleuca), 2. Andean Bear (Tremarctos ornatus), 3. Sun Bear (Helarctos malayanus), 4. Sloth Bear (Melursus ursinus), 5. Asiatic Black Bear (Ursus thibetanus), 6. American Black Bear (Ursus americanus)

Distribution. Andes Mountains of Venezuela , Colombia , Ecuador , Peru and Boliva, with controversial evidence of existence in N Argentina .