NEWS – Montane birds hit by forest logging, climate change, finds IISc study

WHAT IS FOREST LOGGING

• Practice of cutting down, removing, or harvesting trees from forests for various purposes, primarily to obtain wood and other forest products
• While logging is a significant economic activity with various applications, it raises environmental, social, and economic concerns

WHAT DOES THE STUDY SAY

• Researchers studied bird communities in tropical mountains over 10 years
• Forest logging can lead to loss of large-bodied species and decrease biodiversity
• Underlined the need to safeguard primary forests to mitigate the effects of climate change
• Understory (vegetation layer beneath the canopy) insectivores are negatively influenced by logging and show steep declines in numbers
• Logged forests also have lower densities of foliage-dwelling insects, reducing the resource availability for the birds that reduces the abundance of large species
• Tropical montane forests are critical biodiversity centres and unique ecosystems that can start at about 150-200 m and reach up to 3,500 m high up on mountains. In tropical mountains, each species has a particular niche where it is found. This restriction creates much more diversity in a small space
• Birds of tropical mountain ranges are extremely temperature-sensitive and are responding to global heating rapidly
• Many bird species have started shifting to higher elevations due to rising temperatures. Logged forests have higher average temperatures and lower humidity than primary forests
• Smaller birds seem to colonise logged forests better because they can tolerate higher temperatures, while the density of larger bird species appears to be increasing in primary forests
• Eaglenest Wildlife Sanctuary is situated in the biodiversity hotspot of Eastern Himalayas, Arunachal and is home to over 500 bird species. The final analysis included 4,801 understorey insectivores from about 61 species