NEW DELHI — A sharp increase in human activity is forcing the Himalayan monal pheasant to move higher into the mountains and change how it communicates, according to two studies conducted by Indian researchers over five years.
The bird, native to Himalayan mountain forests, is considered a key indicator of ecosystem health in the region. Researchers from Uttarakhand identified mounting pressures on the species as infrastructure development and tourism expand across the mountains.
Dr. Rajeev Lochan, lead researcher for both studies, said the monal's narrow habitat range and seasonal movement between lower montane and high-elevation alpine zones make it a crucial barometer for the northwestern Himalayas.
The first study found that monals are being displaced to higher elevations as their natural habitat in alpine meadows above the tree line becomes crowded with human activity. The second study determined that increasing noise from human activity is altering the monal's communication with potential mates and rivals. Birds in noisier environments produced calls with significantly higher peak frequencies than those in quieter habitats.
Using recording devices, researchers detected subtle pitch changes that might go unnoticed by the human ear, particularly at the higher end of the birds' call frequencies. This suggests an adaptive capacity to adjust calls to their surroundings.
Dr. Lochan warned that if the monal is facing such challenges, ecological disturbances might also affect other bird species more severely. He emphasized the monal's role as an indicator of the broader health of the fragile Himalayan ecosystem.
Vishal Singh, an environmental practitioner focusing on ecology and climate issues in the Himalayas, said the studies offer a critical warning for more vulnerable species. If the monal is compelled to change both its voice and location, he said, the responses of more sensitive species warrant immediate attention.
Singh noted that the region's economic development is not aligned with its ecological integrity, with unregulated tourism and heavy urbanization pushing the Himalayan ecosystem toward a tipping point.
Climate change presents another major threat to the region's already vulnerable biodiversity. The first study projects climate change will continue shrinking and destabilizing the Himalayan monal's habitat across the Indian Himalayas through 2100 under multiple climate scenarios. The alpine meadows where the birds are currently found also serve as some of the Himalayas' most important seasonal grazing areas.
