A colorful bird in the Himalayan mountains is changing how it sings to deal with human noise. The monal is a bright pheasant known for its green, blue, and copper feathers. It moves up and down the mountains during different seasons.
Researchers studied monal calls in two different mountain valleys. In one busy valley with many tourists and cars, the birds sang at a higher pitch. Their calls were also shorter. In a quiet valley with few visitors, the birds sang normally. Raising their pitch helps the birds hear each other over traffic and human noise.
Scientists say this change shows the birds are flexible, not that their bodies have permanently changed. However, increasing noise, building work, and warmer weather are pushing these birds higher up the mountains. If human activity continues to grow, it may become harder for the birds to find mates and survive.