Agricultural growth and its impact on the spectacled bear's natural habitat is considered to be the most serious cause of reduction in population size of the species. Historical hunting and trade in bear parts probably also contribute to the shrinking populations.
Few means to protect the species
There is very little protection for this bear and the National Parks of South America have limited budgets and incentives to implement their work. Moreover, there is insufficient institutional and legal capacity for managing and protecting these areas.
Also naturally vulnerable
Several of the species life history traits make it extremely vulnerable to human pressures. Its low natural density in many regions, low reproductive rate, long period of parental dependency, and reduced genetic variability in natural conditions could be risk factors when one also considers the reduction of its natural habitat and the continuous population depletion.
The elimination of just one spectacled bear may have a significant impact on populations made up of only a small number of individuals. In Peru there are reports of inbreeding, resulting in decreased adult size and reduced number of offspring.
The impact of domestics
In addition, the introduction of domestic species may adversely affect bear populations. Cattle, goats, and sheep, as well as dogs, cats, and rats, could favor the presence of diseases that would affect the survival of wild bears entering into contact with these animals, as documented in populations of the mountain tapir in Ecuador.
With regard to the bear's natural enemies, cubs may be attacked by pumas or occasionally jaguars and even other male adult bears. Once bears reach adulthood, there are no real natural enemies other than humans.
Habitat loss and degradation
Loss and fragmentation of the species habitat is due to the construction of roads the destruction of forests for illicit crops such as coca and opium poppy, and the use of grazing areas for cattle farming. Protected areas conserving bear habitats and some of their populations are not large enough for the species' survival throughout its range.
Current land use patterns include the felling of trees, land clearing, and extraction of timber and firewood for farms in the higher mountainous areas. Along with infrastructure development (highways and roads, oil pipelines, gas pipelines, dams, and high tension lines), the advances in mining, petroleum exploitation and other industries, and the expansion of illegal crops have fragmented the original habitat of the spectacled bear into at least 113 patches of wilderness in the mountainous region between Venezuela and northern Peru.
Because the species habitat in high mountain ecosystems is being fragmented, the populations are being separated, which increases the risks of inbreeding.
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Hunting is one of the major causes of population reduction of this species. Local inhabitants kill bears for diverse reasons, including subsistence hunting, protection against attacks to livestock and crops (especially maize), fear of the animal due to cultural reasons, and occasionally the illegal traffic of bear parts and live specimens (see next section). Although the impact of this threat has not been precisely assessed, it is calculated that around 200 bears are hunted down each year in the region.
Spectacled bears are hunted for their meat, skin, fat and claws, which are all in demand locally. The gall bladders are valued in traditional oriental medicine and can fetch a high price on the international market; recent estimates put the price at US$ 150 for one, which is five times the average monthly wage in Ecuador.
There is a large market for bear paws, with one paw bringing in between US$10 and US$20 dollars. This problem is not only connected to cultural beliefs such as using certain parts of the animal (e.g. bile, fat and the penis) for curative purposes, but also to the economic needs of indigenous and rural populations.
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Many of these threats can be largely attributed to the inequity in land tenure. In the most productive areas of the Northern Andes, property is concentrated in the hands of a few, which means that the poorest inhabitants are forced to occupy the limited land available on the fragile hillsides of mountains inhabited by the spectacled bear.
The conditions of rural poverty and the worsening of social conflicts in these countries have intensified this process, which, in the case of Colombia, has been undoubtedly associated with armed conflict and illegal crops.