Studies find Himalayan monal changing its pitch as human activity rises

Two studies by Indian researchers, carried out over five years, found that a sharp increase in human activity is affecting the way the Himalayan monal lives and communicates, the BBC reported. The monal is a pheasant native to Himalayan mountain forests. The male has distinctive green, blue and copper feathers.

One study found the birds are forced to move higher in the mountains as their natural habitat in the alpine meadows above the tree line gets crowded. The other says the monal is changing its pitch to cut through human noise in a busy valley. According to the BBC, infrastructure development and tourism are squeezing its habitat, while increasing noise is altering how it communicates with potential mates and rivals.

Dr Rajeev Lochan, lead researcher of both studies, told the BBC they chose to study the monal because the bird has a narrow habitat range, moving seasonally between the lower montane zone (an ecological belt on the lower mountain slopes) and high-elevation alpine zones. He said this makes it a key indicator of ecosystem health in the north-western Himalayas. "If the species is facing issues on this particular landscape, there might be a chance that the ecological disturbances are affecting other birds too," Lochan said.

Vishal Singh, an environmental practitioner working on ecology and climate issues in the Himalayas, said the two studies give a useful warning for other more vulnerable species. "If the monal is forced to change both its voice and its address, how are the more sensitive species responding?" Singh said. He said that at a broader level, the problem is that the economic development of the region is not aligned to its ecological integrity.

According to the first study, climate change is projected to continue shrinking and destabilising the Himalayan monal's habitat across the Indian Himalayas through 2100 under multiple climate scenarios. The monal is the state bird of Uttarakhand in India and the national bird of Nepal. Researchers say rapid infrastructure expansion in the past decade has made more places accessible, increasing footfall and disrupting wildlife.