Rising Noise and Shrinking Habitats Are Forcing the Himalayan Monal to Adapt Its Voice and Move Higher

Human activity in the Himalayas is leaving its mark on one of the region's most celebrated birds, according to new research from India. Two separate studies conducted over five years suggest that the Himalayan monal, a striking pheasant native to mountain forests, is being forced to change both how it communicates and where it lives as infrastructure, tourism and climate pressures mount.

The monal occupies a special place in Himalayan culture, folklore and identity. The male bird is instantly recognisable for its iridescent plumage, which blends shades of green, blue and copper. It serves as the state bird of Uttarakhand in India and the national bird of Nepal, a status that reflects its symbolic importance across the mountain range.

Researchers based in Uttarakhand carried out the two studies, which together flag significant threats facing the species. One found that the birds are retreating to higher elevations as their natural habitat in alpine meadows above the tree line becomes increasingly crowded. The other concluded that the monal is altering the pitch of its calls to be heard over human noise in a busy valley.

Vishal Singh, an environmental practitioner who works on ecology and climate issues in the Himalayas, said the findings carry a warning that extends well beyond a single species. He noted that if the monal is being forced to change both its voice and its address, more sensitive birds may be responding even more dramatically.

Dr Rajeev Lochan, who led both studies, explained that the monal was chosen as a subject because it occupies a narrow habitat range. The bird migrates seasonally between the lower montane zone on the mountains' lower slopes and the high-elevation alpine zones, a pattern that makes it a useful indicator of overall ecosystem health in the north-western Himalayas. He added that if the species is struggling in this landscape, other birds may also be affected by the same ecological disturbances.

According to the first study, climate change is expected to keep shrinking and destabilising the monal's habitat across the Indian Himalayas through the year 2100 under a range of climate scenarios. The birds currently depend on alpine meadows situated high above the forests, which rank among the Himalayas' most important seasonal grazing grounds and biodiversity-rich habitats.

To reach their conclusions, the researchers modelled how climate change could shift the areas suitable for the monal across the Indian Himalayan region, focusing on Uttarakhand and Himachal Pradesh. The work drew on the same types of global climate models and emissions scenarios used by the Intergovernmental Panel on Climate Change, the United Nations' climate science body, for its own assessments. The model assumes that the birds will continue to require the climate conditions currently found in alpine meadows, an assumption the researchers describe as reasonable but not guaranteed.

Lochan said the birds are already moving gradually upwards as snow melts and vegetation spreads, opening up new terrain. At the same time, he explained, they are being pushed higher because human encroachment is reducing the alpine meadows they naturally depend on. As the climate shifts, their seasonal migration could become increasingly difficult, driving them towards higher elevations and into smaller, fragmented patches of suitable land.

The consequence, the study warns, is that monal populations could end up scattered across disconnected pockets. That fragmentation would limit breeding between different groups and raise the risk of long-term population decline or local extinction, a threat the species already faces.

The second study, also led by Lochan alongside Dinesh Kumar Sharma and Anand Kumar of Hemvati Nandan Bahuguna Garhwal University, examined changes in the bird's behaviour. The team carried out fieldwork in two valleys within the Kedarnath Musk Deer Sanctuary in Uttarakhand, including Chopta, a tourist destination known for heavy traffic.

The research indicates that the monal is adjusting its call pitch to cut through the noise generated by human activity in the busy valley. This matters because the bird relies on vocal communication to attract potential mates and to interact with rivals, meaning disruptions to its calls could affect reproduction and social dynamics.

Taken together, the two studies portray the monal as a stand-in for the health of a fragile Himalayan ecosystem that is being pushed towards a tipping point. The region has long attracted tourists, trekkers and researchers thanks to its scenery and biodiversity, but rapid infrastructure expansion over the past decade has opened up more areas, increasing visitor numbers and disturbing wildlife. That pressure comes on top of growing evidence that climate change is emerging as another major threat to the region's already vulnerable biodiversity.

Singh framed the underlying problem in broad terms, arguing that economic development in the region is not aligned with its ecological integrity. While many factors are at play, he suggested that the tension between growth and conservation lies at the heart of the challenges now facing species such as the monal.

The monal's dual response, changing its voice and shifting its range, offers researchers a rare window into how wildlife copes when human pressures and a warming climate converge. The findings raise broader questions about how less adaptable and more vulnerable Himalayan species are faring under the same conditions.