Home Nepal community Rising temperatures destroy Asiatic black bear habitat in Himalayas

Rising temperatures destroy Asiatic black bear habitat in Himalayas

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The Asiatic black bear once extended as far west as Germany and France. Native to the hill forests of Asia, the bear range currently extends from Iran, through the Himalayas to the Hindu Kush, Japan and the Russian Far East. But by 2100, researchers say, climate change will further alter the species’ distribution.

The Asiatic black bear is also known as the “moon bear”, referring to the white crescent-shaped mark on its chest. Classified as a vulnerable species by the International Union for the Conservation of Nature, this medium-sized bear is threatened by habitat loss and poaching.

Climate effect

As temperatures warm, forests begin to grow at different altitudes. Bears depend on forest vegetation for food, which means that the location of suitable habitat will change. This, along with land use planning, agriculture and deforestation, could lead to habitat fragmentation, forcing bears to form isolated subpopulations and making them vulnerable to population decline.

In a new study published this month, a team of researchers from Australia, China and the United States modeled the impact of climate change on the range of the Asian black bear in the Hindu Kush Himalayas, an area of ​​4.19 million square kilometers across Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal and Pakistan. The researchers used two climate scenarios in the study: a worst-case scenario (RCP 8.5) and a “probable” scenario (RCP 4.5).

The authors modeled the suitability of current and future habitats for Asian black bears using 561 records of bear presence, 19 climate variables (such as annual temperature range and precipitation seasonality), and five variables. non-climatic (such as altitude, index of human influence and land-use change).

There was an expected overall reduction in suitable habitat in the eight countries studied, from 487,036 km² currently to 458,060 km² in the RCP 4.5 scenario – a loss of almost 30,000 km². Even in areas where an increase in suitable habitat is predicted, habitat fragmentation and human-bear conflict could threaten populations.

The model found that the greatest amount of current suitable habitat was in China, followed by India, Nepal and Myanmar.

Forced to higher ground

The study found that suitable habitat for Asian black bears is primarily found at elevations of 1,501 meters to 3,000 meters above sea level. Going forward, in both climate scenarios , this is expected to move both north and at elevations above 3,500 m, with suitable habitat declining in the southern part of the species’ current range.

For example, bear habitat is expected to decrease in the lower elevations of Nepal and in southern Sichuan Province in China, but increase in northwest Sichuan, northern and northeastern Kashmir (in India and Pakistan), Himachal Pradesh and along the Pakistan-Afghanistan border.

“Our results indicated a range shift to higher elevations,” said Babar Zahoor, an ecologist at Tsinghua University in China and lead author of the study. The third pole. “Thus, in countries or regions with mountains or forests, not above this elevation, the species may be under the greatest threat of extinction.”

“The treeline change is expected to occur in the future due to climate change and there may be a small gain in black bear habitats at higher elevations and a small loss. at lower altitudes, “said S Sathyakumar, senior scientist in the department. of endangered species management at the Wildlife Institute of India, a government-affiliated research institution.

Sathyakumar, who was not involved in the study, added that because the black bear is a forest species and largely feeds on fruits, nuts and vegetation, climate change could impact the ability to the forest to provide suitable food for black bears in the future.

The study predicted that in China and Myanmar, suitable habitats would decrease by about 30% and 50% respectively under the RCP 4.5 climate change scenario. In Bangladesh, the model predicted a reduction in suitable habitat from 35% to 58%. With Asian bear populations already low and fragmented in Bangladesh, the authors say this could increase the risk of the species becoming extinct in the country.

One of the largest reductions (48%) in suitable habitat has been projected in lowland areas of Nepal.

However, Rabin Kadariya, conservation officer at the Bardia Conservation Program, a project of the Nepalese NGO National Trust for Nature Conservation, questioned whether black bear habitat would in fact decline in Nepal. Kadariya, who was not involved in the study, said that “studies have shown that forest cover has increased in the hilly areas of Nepal where black bears are found due to [the] Community forestry program, reducing dependence on forests due to changing livelihoods and migration of people from the hills to neighboring towns ”.

He added that the black bear has been recorded across a wide range of altitudes in Nepal, from 260 m in the Babai Valley of Bardia National Park to the mountains at around 3,600 meters. “[Over] Over the past 20 years, black bear habitat must improve through successful community forest management in the hilly region.

In the central Himalayan area of ​​the Hindu Kush, the Kashmir region (India and Pakistan), Uttarakhand and Bhutan, the model predicted that suitable habitat for the Asian black bear would remain largely unchanged in the future. Meanwhile, in Afghanistan and Pakistan, suitable habitat is expected to increase. However, the authors warn that human activities, such as habitat fragmentation, poaching, and conflict with humans, could affect bear populations.

Melissa Songer, one of the study authors from the Smithsonian Conservation Biology Institute in the United States, said: “The decline in suitable habitat in Nepal and Bangladesh and the increase in Pakistan and Afghanistan are linked to changes in vegetation along geographic dimensions.

She explained that this change is due to temperature variability in the Hindu Kush Himalayan region, resulting in habitat loss in the east, but areas of continued suitability in central and western parts of the region. the Hindu Kush Himalayas.

Confluence of threats

Both Sathyakumar and Kadariya have said that retaliatory killings and the illegal trade in bear parts – current threats to the Asian black bear – are likely to have a bigger impact than climate change on the future of Africa. species.

Sathyakumar said, “We need regular monitoring of conflict hotspots by well-trained frontline personnel to prevent and manage conflict, and large-scale intelligence gathering to control poaching and smuggling of parties. bear. “

According to the International Union for the Conservation of Nature, Asian black bears are mainly poached for their gallbladder and paws. Bear paws are eaten as a delicacy in parts of China and Southeast Asia, while bear bile – extracted from the gallbladder – is used in some traditional Asian medicines. Elsewhere in the species’ range, such as Pakistan, live bears are illegally captured to bait bears.

Songer said that as climate change affects the range of Asian black bears, there will be an increase in human-bear conflict and the intensity of poaching. “The model’s overall prediction is a reduction in habitat available to bears,” Songer said. “Ultimately, less habitat will mean less available forage and [an increased] need to plunder the crops.

A study of the human-bear conflict in Azad Jammu and Kashmir, Pakistan, found that between 2013 and 2015, 40,280 kg of maize and 1,49,300 kg of fodder were damaged, with an estimated loss of $ 22,040 for farmers.

Human-bear conflicts have escalated in Kashmir over the past decade, causing serious injuries and deaths. Studies have shown that 90% of attacks occur during the day, around agricultural areas.

“The increase in poaching could result from loss of livelihoods due to looting of crops and an effort to reduce the bear population in order to reduce conflict,” Songer said.

Sathyakumar recommended working with local communities to reduce crop and livestock losses. The measures include the use of barriers, bear repellents, better shelter for livestock, insurance plans and, most importantly, providing victims of bear attacks with support for treatment and resources. subsistence.

This article first appeared on The Third Pole.


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