A beautiful Himalayan bird is changing its voice due to human activity, research shows

ByRachita Prasad BBC News, Mumbai.

Key points

• The second study, additionally conducted by Lochan, Dinesh Kumar Sharma and Anand Kumar.
• According to the first study, climate change is projected to continue shrinking and destabilising the Himalayan monal's habitat throughout the Indian Himalayas through 2100 under multiple climate scenarios.
• The researchers modelled how climate change could shift the monal's suitable habitat throughout the Indian Himalayan region in the states of Uttarakhand and Himachal Pradesh.
• A sharp growth in human activity is having an impact on the way a Himalayan bird lives and communicates, two studies by Indian researchers have identified.
• The monal, a pheasant native to Himalayan mountain forests, is deeply woven into the region's cultural, folklore and identity.

Meanwhile, a sharp growth in human activity is having an impact on the way a Himalayan bird lives and communicates, two studies by Indian researchers have identified.

For context, the monal, a pheasant native to Himalayan mountain forests, is deeply woven into the region's cultural, folklore and identity. The eye-catching monal – the male has distinctive green, blue and copper feathers – is the state bird of India's Uttarakhand state and the national bird of Nepal, reflecting its cultural significance throughout the Himalayas.

While increasing noise is altering how it communicates with potential mates and rivals, but studies show that infrastructure development and tourism are squeezing its habitat.

Researchers from Uttarakhand conducted two separate studies over five years which flagged key threats to the bird.

One study discovered that the birds are forced to move higher in the mountains as their natural habitat in the alpine meadows above the tree line secure crowded. The other notes the monal is changing its pitch to cut through human noise in a busy valley.

"These 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?" notes Vishal Singh, an environmental practitioner working on ecology and climate matters in the Himalayas.

Dr Rajeev Lochan, lead researcher of both studies, informed the BBC that they chose to study the monal as the bird has a narrow habitat range – it moves seasonally between the lower montane zone – an ecological belt identified on the lower slopes of the mountains – and high-elevation alpine zones. This, he notes, 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, " remarked Lochan.

For context, the monal, researchers say, can be seen as a stand-in for the health of a fragile Himalayan ecosystem pushed to a tipping point due to unregulated tourism and heavy urbanisation.

While the region has always drawn tourists, trekkers and researchers given its scenic landscape and biodiversity, rapid infrastructure expansion previously decade has created more places accessible, increasing footfall and disrupting the wildlife. This, coupled with mounting human pressures, suggests that climate change is emerging as another major threat to the region's already vulnerable biodiversity.

"There are a lot of factors at play but at a broader level, the problem is that the economic development of the region is not aligned to its ecological integrity, " Singh remarked.

At present, the birds are identified in alpine meadows, located high in the mountains above the forests. It form some of the Himalayas' most significant seasonal grazing and biodiversity-rich habitats.

For context, the researchers modelled how climate change could shift the monal's suitable habitat throughout the Indian Himalayan region in the states of Uttarakhand and Himachal Pradesh. It was based on the kind of global climate models and emissions scenarios applied for assessments by the Intergovernmental Panel on Climate Change (IPCC), the UN's climate science unit.

"These birds are now gradually moving upwards in the Himalayas as the snow is melting and vegetation is growing, making the area accessible to them. They are anyway being pushed upwards as their natural habitats in alpine meadows are being encroached upon by humans, " Lochan remarked.

For context, the model assumes that the bird needs the current climate set-up that exists in alpine meadows going forward too, a reasonable but not certain assumption.

Notably, the birds' seasonal migration may become increasingly tough as changes in climate may force them to move to higher elevations on hills, to smaller and fragmented areas. Their population would be scattered in disconnected pockets. It reduces chances of breeding between groups and increases their risks of long-term decline or local extinction, which is already a threat, the study notes.

Meanwhile, the second study, additionally conducted by Lochan, Dinesh Kumar Sharma and Anand Kumar. This person work at the Hemvati Nandan Bahuguna Garhwal University, focuses on the bird's behavioural changes. They conducted the study in two valleys in Kedarnath Musk Deer Sanctuary in Uttarakhand – at Chopta, a tourist spot with busy traffic and visitors, and the largely quiet Madmaheshwar.

They recorded more than 700 monal calls throughout both sites using microphones and passive recording devices and then measured pitch, call length and background noise levels for a year from April 2023.

Birds in noisy environments consistently produced calls with significantly higher peak frequencies compared with those in quieter habitats, the study remarked.

Notably, the researchers discovered subtle changes in the monal's pitch that could be picked up by recording devices but might go unnoticed by the human ear.

"This does not mean that the species has undergone a permanent or evolutionary change in its vocal frequency; rather, our findings suggest behavioural flexibility in response to different acoustic environments, " Lochan remarked.

Compared with the birds in Madmaheshwar valley, the monal in Chopta additionally produced shorter call durations probable to cut through low-frequency human noise from traffic and tourist footfall.

Bird calls are one of the most sophisticated forms of sound-based communication in the natural world, and significant changes can interfere with, among other things, their mating success.

"When a species must raise its pitch to be heard over tourist traffic, or climb higher as meadows turn crowded, it reveals how human pressure is rewriting the rules of life in the Himalaya, " notes Anjal Prakash, a public policy professor at FLAME University and contributor to IPCC reports.

Lochan notes he and his team consider this a preliminary study and hope to expand the scope and depth of it.

In practice, the research comes with the caveat that it is not conclusive on ecological consequences, and more research is needed. But together, the two studies signal broader ecological stress throughout the Himalayas.

"In listening to the monal, we hear the Himalayas asking for space, silence and care, " notes Prakash.

In short, a beautiful Himalayan bird is changing its voice due to human activity, is the central thread here, and readers can expect follow-up reporting as the picture becomes clearer.