Decline of forest bird species in the western Himalayas
Invasion by non-native species, land use changes have led to a decrease in the abundance of important birds
With extremely cold winters and pleasant summers, the state of Uttarakhand is home to the temperate forests of the Western Himalayas which are home to a large number of endemic bird species. A new study who analyzed these natural forests dominated by oaks and modified forests noted that there was a drastic loss of bird species in all modified landscapes.
The researchers studied an area of approximately 1,285 square kilometers between elevations of 1,700 and 2,400 meters. Six main types of land use which included natural oak forest, degraded oak forest (little used), cut oak forest (intensively used), pine forest, areas of agricultural cultivation and sites with buildings have been studied.
The results showed that there was low species diversity in monoculture areas and urban sites. They also noted a drastic loss of pollinating birds and insectivores in degraded forests, monocultures and urbanized sites. The results were recently published in Global ecology and conservation.
Ghazala Shahabuddin, first author of the article from the Center for Ecology, Development and Research, Dehradun, adds: “We have also noticed a sharp decline in some of the habitat guilds in areas that have experienced a change in population. land use.
Habitat guilds are groups of bird species that have common habitat preferences. For example, forestry specialists include species that feed and breed only in dense protected oak forests at this elevation, while forestry generalists can adapt to altered habitats such as orchards and degraded forests.
Researchers noted that many of the species that abandoned the modified lands were recognized oak forest specialists, such as the red-bellied woodpecker, yellow ribbon, red sibia, white-throated black-throated thrush and warbler. black-faced.
Another article published by the group looked at woodpeckers in the region to understand how they can be used as indicators of bird diversity and also to understand habitat degradation.
They found that the higher the number of woodpeckers at a site, the higher the richness of all other birds. “The cavities that woodpeckers make in trees are used by a number of other birds for nesting. This is perhaps the main reason that peaks improve diversity in a region. Woodpeckers are known to abandon their cavities and even be chased out of their own cavity by other birds, ”explained Tarun Menon, one of the authors of the article who is currently a doctoral student at the Indian Institute of Sciences in Bengaluru. .
They also noted that two species (the red-bellied woodpecker and the great yellow ribbon) had great potential as indicators of forest quality, as they were more likely to be found in dense canopy forests with larger and larger trees on which they preferred to feed.
“With the increase in tourism and other human activities in the region, we are seeing a rapid invasion by non-native species. One would not expect to see pigeons and black kites at these altitudes, but with the increase of concrete urban ghettos, these birds have become a common sight now, ”adds Rajkamal Goswami who was associated with the Center for the ecology, development and research, Dehradun, while carrying out field surveys. He is currently working with the Ashoka Trust for Research and the Environment (ATREE) and is one of the authors of the article. He adds that land use changes are also leading to the depletion of the water table and the drying up of perennial sources in these regions. “The loss of forests and the intensification of land use have resulted in a significant decrease in the abundance of important birds known to provide critical ecosystem functions and services such as pollination and pest control,” he adds. -he.