Declining “forest bird species” in Western Himalayan region

What is the News?

According to research published in Global Ecology and Conservation, there has been a decline in forest bird species in the Western Himalayas Region.

Note: The State of Uttarakhand has extremely cold winters and pleasant summers. It is home to the Western Himalayan temperate forests. These forests harbour a large number of endemic bird species.

About the Research:

• The researchers studied an area of about 1,285 square kilometres between the altitudes of 1,700 and 2,400 metres in the Western Himalayas Region.
• Land Types: They studied six land-use types within moist temperate forest which includes:
  • Natural (protected) oak forest,
  • Degraded (lightly used) oak forest,
  • Looped (heavily used) oak forest,
  • Pine forest
  • Agricultural cultivation area and
  • Sites with buildings.

Key Findings:

• Firstly, there was a moderate to drastic forest bird species loss in all modified land-use types in comparison to natural oak forest.
• Secondly, a strong decline was noticed in some habitats guilds. It was especially in the areas of visible land-use change.
  • Habitats guilds are groups of bird species that have common habitat preferences.
• Thirdly, the species that dropped out of the modified land areas were recognised as oak forest specialists. Such as Rufous-bellied woodpecker, greater yellow nape, rufous sibia, white-throated laughing thrush and black-faced warbler.
  • Forests Specialists include species that search for food and breed only in dense protected oak forests at this altitude.
  • On the other hand, Forest Generalists include species that can adapt to modified habitats such as orchards and degraded forests.
• Lastly, the reasons for the loss of forest bird species in the region were found to be:
  • Tourism and other anthropogenic activities
  • Rapid Invasion by non-native species. For example, Pigeon and Black Kites are not found in these High Altitudes. But with increasing concrete urban ghettos, these birds have become common in this region.

Study on Woodpeckers:

• Firstly, the researchers also studied the woodpeckers in the Western Himalayas region. This is to understand how they can be used as indicators of bird diversity and also to understand habitat degradation:
• Secondly, they found that the higher number of woodpeckers at a site, results in higher richness of all other birds.
  • Reason: The cavities that woodpeckers make on trees are used by a number of other birds to nest in. This may be the primary reason how woodpeckers enhance the diversity in a region.
• Thirdly, the two species (Rufous-bellied woodpecker and greater yellow nape) have shown great potential as indicators of forest quality. They are most likely to be found in dense canopied forests with larger and taller trees on which they preferred to forage.

Source: The Hindu