Rising temperatures push cold-adapted migratory species into smaller, fragmented habitats: Report

New Delhi, Oct 3 (PTI) Migratory wildlife, including Himalayan species such as musk deer and snow trout, are facing increasing survival challenges, with rising temperatures forcing cold-adapted species to move higher into smaller, fragmented habitats, according to a new report.

The report released on Friday by the UN Convention on the Conservation of Migratory Species of Wild Animals (CMS), based on an international expert workshop held in Edinburgh earlier this year, said climate-driven habitat shifts are compounding existing pressures from human activity.

The researchers also warned that Asian elephants are encountering a "habitat gridlock" with limited movement. "Climate and land-use changes are shifting elephant habitats eastward, but with limited connectivity, most elephants in India and Sri Lanka cannot follow, escalating human-elephant conflicts," the report said.

The Himalayan ecosystem, already vulnerable to rising temperatures, is undergoing rapid changes.

"Cold-adapted wildlife, such as musk deer, pheasants and snow trout, are being pushed upslope into smaller, fragmented refugia, with some small mammals projected to lose over 50 per cent of their range," the report said.

Professor Sathyakumar Sambandam of the Wildlife Institute of India (WII), who contributed a case study, reiterated the concern surrounding the shrinking refugia. "We predict that high-altitude protected areas (PAs) may buffer climate impacts, but many areas outside PAs also serve as climate refugia. Conservation efforts must secure movement corridors, habitat islands and refugia to mitigate biodiversity reorganisation under climate change," he said.

As part of one of India's key missions -- the National Mission for Sustaining the Himalayan Ecosystem -- long-term wildlife monitoring across the longitudinal and elevational gradients of the Himalayas was initiated in 2015.

Its investigations focus on four major river basins -- Beas (Himachal Pradesh), Bhagirathi (Uttarakhand), Teesta (Sikkim) and Kameng (Arunachal Pradesh) -- using standardised taxa-specific sampling to document long-term trends in species distribution and the impact of climate change.

A multi-species, multi-model ensemble assessed climate-change impacts on 36 species of mammals, 27 species of birds and two fish species under different Shared Socioeconomic Pathways (SSPs), the report said.

Small mammals in Uttarakhand could lose more than 50 per cent of their range, while the migratory snow trout is expected to shift into higher-altitude rivers, creating what scientists call an "altitude squeeze". Pheasants, too, face increasing habitat fragmentation in the Eastern Himalayas, the report added.

The CMS workshop found that climate change is affecting migratory species worldwide. Shorebirds in the Arctic are hatching out of sync with insect availability, cutting chick-survival rates.

Whales, including the critically-endangered North Atlantic right whale, are being forced into dangerous detours as prey shrinks in the warming seas. In South America, an Amazon heatwave in 2023 killed hundreds of river dolphins when water temperatures spiked to 41 degrees Celsius, the workshop's findings noted.

Marine ecosystems are also under strain. Seagrass meadows, which store nearly 20 per cent of the world's "blue carbon" and provide food for dugongs and turtles, are being damaged by heatwaves, cyclones and sea-level rise. In the Mediterranean, fin-whale habitats could shrink by up to 70 per cent by mid-century.

CMS Executive Secretary Amy Fraenkel described migratory animals as the planet's "early-warning system". "From monarch butterflies vanishing from our gardens to whales veering off course in warming seas, these travellers are sending us a clear signal. Climate change is having impacts now and without urgent action, the survival of such species is in jeopardy," she said.

The report warned that a fifth of migratory species are threatened with extinction. For migratory fish, the share climbs up to 97 per cent.

"Whales support carbon-absorbing seagrass ecosystems and themselves store vast amounts of carbon. Each elephant in the Congo contributes USD 2.6 million worth of carbon storage services over its lifetime," it said. PTI UZM PRK RC