Avalanches primarily cause higher mortality of ungulate mammals in snowy mountains: Study

Bhubaneswar: Mountain-adapted animals especially in the snowy regions face a decline in their slow-growing population primarily due to climate-driven avalanches, which cause around 23 to 65 percent of all mortality depending on their habitation area, revealed a recent study.

Seasonal fluctuations influence the occurrence of fatalities of these hoofed and quadruped herbivores, correlating closely with patterns of spatial movement and the utilisation of avalanche-prone terrain.

Snow is a significant climate-responsive element of the Earth’s surface and it serves as a catalyst for vital ecosystem processes. It is imperative to understand how snow impacts sentinel species within swiftly evolving mountain ecosystems, a panel of researchers opined in journal the ‘Nature Communications’.

Mountain environments experience rapid climate change, leading to significant alterations in sensitive ecological communities and processes. Various new stressors pose threats to the species like alpine ungulates, which possess specialised adaptations and inhabit narrow biophysical niches.

Formation of an avalanche results from the interplay of weather, snowpack, and terrain. The risk of avalanches is influenced by topography and the presence of snowpack vulnerabilities, which fluctuate spatially and temporally.

The utilisation of avalanche terrain by mountain goats is extensive and correlated with mortality. However, understanding mountain goat use of dangerous, avalanche-prone terrain requires broader consideration of how avalanches might influence multiple components of fitness.

Mountain goats utilise steep terrain to mitigate predation risk, with optimally selected slope angles (36−58°) closely corresponding with the most avalanche-prone slopes (30−45°).

Climate change impacts on snow features will be crucial for mountain ungulates in the future. This will alter when and where avalanches occur, impacting the risk of exposure and entrapment.

The researchers merged a comprehensive set of field data on mountain goat behaviour with detailed terrain information to assess the impact of avalanches on population dynamics of mountain wildlife.

“Whereas effects of snow on food availability, energy expenditure, and predation are well documented, we report how avalanches exert major impacts on an ecologically significant mountain ungulate,” a member of the panel Gabriel J. Wolken said.

Notably, the researchers arrived at the conclusion by using long-term GPS data and field observations carried out on four populations, over a period of nearly 17 years.

[This story is a part of ‘Punascha Pruthibi – One Earth. Unite for It’, an awareness campaign by Sambad Digital.]