Tourists, Traffic & Pilgrims Are Making the Himalayas Noisier. This Uttarakhand State Bird Is Adapting

The Himalayan monal, Uttarakhand's state bird, is adapting to increasing human-generated noise in parts of the Himalayas by altering its vocalizations, according to a study published in Behavioural Processes in August 2025. Researchers from Hemvati Nandan Bahuguna Garhwal University found that in noisier landscapes, the birds produced calls with higher peak frequencies and slightly longer durations, likely in an effort to be heard amidst the sounds of traffic, tourists, and pilgrims.

The study, conducted by Rajeev Lochan, Dinesh Kumar Sharma, and Anand Kumar, analyzed 719 monal calls recorded between April 2023 and June 2024. They compared the relatively quiet Madmaheshwar Valley, which has minimal human activity and no road, with the busier Chopta Valley within the Kedarnath Musk Deer Sanctuary, where roads, vehicles, and human presence are more prominent. The difference in peak frequency was around 171 Hz lower in the quieter habitat at the median level, with the pattern being strongest at the upper end of the birds’ vocal range, where the statistical model explained about 73.4% of the variation.

This vocal shift is interpreted as a response to acoustic masking, where background noise overlaps with an animal's communication signal, making it harder to detect. By shifting calls to higher frequencies and slightly increasing their duration, the monal appears to be attempting to maintain effective communication in a louder soundscape. The Himalayan monal's native range spans from Afghanistan and Pakistan through Nepal, India, southern Tibet, and Bhutan, inhabiting alpine and subalpine areas between 2,400 and 4,500 metres. While currently classified as Least Concern on the IUCN Red List, the long-term costs of this adaptation are not yet known.

A separate 2025 study by the same researchers, published in Scientific Reports, projected future habitat suitability for the monal. Under one climate scenario, more than 14% of previously suitable habitat could become unsuitable by 2041–2070, highlighting broader environmental pressures from climate change, land-use change, infrastructure, and tourism. Further research is needed to determine if altered calls affect mate attraction, create physiological costs, or if other Himalayan birds are making similar adjustments.

Why it matters: Understanding how wildlife adapts to human-induced noise is crucial for conservation efforts in changing environments.

Editor's note: Excellent synthesis of the research study, methodology, and the broader environmental context provided in the source.