Decline of Grassland Birds in Nilgiris

A study in Global Change Biology examined 170 years of land-use change in the Nilgiri mountains of the Western Ghats to understand its impact on bird diversity. 

• Researchers combined historical museum specimen records with modern field surveys to track biodiversity trends.

Key Findings from the Study

• Grassland bird decline:
  • The relative abundance of ~90% of grassland birds has dropped.
  • Nilgiri pipit and Malabar lark (grassland specialists) suffered steepest declines.
  • Grassland extent reduced by 80% from 993 sq. km (1848) to 201 sq. km (2018).
• Forest bird stability:
  • The abundance of ~53% of forest birds was relatively stable over the last century.
  • Grasslands were replaced by exotic plantations or woody invasive species, creating alternative habitats for forest-dependent birds.
• Main concern: Grasslands remain poorly recognised in conservation, while focus is often on forests and tree plantations.

About Shola Forests

• Definition: A unique mosaic of montane evergreen forests and grasslands.
• Location: Restricted to tropical high-altitude regions (>1500 m) in the southern Western Ghats.
• Characteristics: Rolling grasslands interspersed with patches of stunted evergreen trees.
• Biodiversity: Habitat for many endemic and endangered plants and animals.
• Ecological Importance: Crucial for sustaining water cycles and maintaining hydrological balance.

About Nligiri Mountains

• Location: Nilgiri Mountains lie at the trijunction of Tamil Nadu, Kerala, and Karnataka in the southern Western Ghats.
• Highest Peak: Doddabetta (2,637 m) is the tallest point in the range.
• Geography: Characterised by rolling hills, deep valleys, and elevated plateaus with unique Shola–grassland ecosystems.
• Ecology: Recognised as a biodiversity hotspot, home to endemic species like Nilgiri tahr, lion-tailed macaque, and Nilgiri pipit.
• Hydrological Role: Acts as a vital watershed, feeding rivers such as the Bhavani, Kabini etc

Role of Natural History Museums

• Biodiversity Repositories: Act as vital stores of biodiversity data, especially in species-rich regions like India.
• Historical Records: Provide information on species distributions, taxonomy, migration, climate responses, and biodiversity collapse.
• Key Challenges: Face issues such as lack of digitisation, limited funding, outdated infrastructure, bureaucratic hurdles, high travel costs, visa restrictions, and disputes over specimen ownership/repatriation.

Insights for Conservation

• Archival Value: Historical archives (specimens, journals, maps) complement field studies by offering long-term biodiversity baselines.
• Grassland Restoration: Emphasise recognition and restoration of grasslands as critical ecosystems.
• Nature-Based Solutions: Stress the need for proper valuation of non-forest habitats and adoption of nature-based solutions to prevent biodiversity loss.

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