Tourism Is Changing the Calls of Himalayan Monal Birds, Study Finds

A study of bird behavior in Uttarakhand’s Kedarnath Musk Deer Reserve has found that Himalayan monal birds respond to tourist noise by changing the pitch and duration of their calls.

Researchers Compare Bird Calls in Busy and Quiet Valleys

The study, conducted by Lochan, Dinesh Kumar Sharma and Anand Kumar of Hemvati Nandan Bahuguna Garhwal University, examined bird behavior in two valleys: Chopta, a popular tourist destination with heavy visitor traffic, and the quieter Madmaheshwar Valley.

Over one year beginning in April 2023, the researchers recorded more than 700 bird calls at both locations. They used microphones and passive recording devices to measure pitch, call duration and ambient noise levels.

Monal Birds Use Higher-Pitched Calls in Noisy Areas

The researchers found that birds living in noisier environments consistently produced calls with significantly higher peak frequencies than birds in quieter surroundings.

Recording devices detected subtle changes in the pitch of the monal’s calls that may not be noticeable to the human ear.

“This does not mean that this species has undergone permanent or evolutionary changes in its vocal frequencies. Rather, our findings suggest that its behavior is flexible in response to different acoustic environments,” Lochan said.

Compared with birds in Madmaheshwar Valley, monals in Chopta are believed to produce shorter calls, helping them avoid low-frequency noise from traffic and tourists’ footsteps.

Human Noise Could Affect Bird Communication

Bird calls are among the most sophisticated forms of voice-based communication in nature. Significant changes to these calls could affect important behaviors, including mating success.

“When species have to vocalize to be heard in tourist cars or climb higher as grasslands become more crowded, it reveals how human pressures are rewriting the rules of life in the Himalayas,” said Anjal Prakash, a public policy professor at FLAME University and a contributor to the IPCC report.

Further Research Is Needed

Lochan and his team describe the research as a preliminary study and hope to expand its scope and depth.

The researchers cautioned that the ecological impact is not yet conclusive and that further research is needed. However, the two studies taken together suggest widespread ecological stress across the Himalayas.

“When you listen to monal, you hear the Himalayas asking for space, silence and compassion,” Prakash said.