Climate Threatens Nilgiri Wood Pigeon Habitat

Climate change could drastically shrink the habitat of the Nilgiri Wood Pigeon by the end of the century, according to a recent scientific study. The species, endemic to the Western Ghats, may face sharp declines in high-suitability habitats as global temperatures rise. Researchers warn that despite its current conservation status, long-term climate projections signal emerging ecological risks.

Study Uses MaxEnt to Model Future Habitat

The study titled “Biogeography and habitat suitability of the Nilgiri Wood Pigeon using MaxEnt”, published in the Proceedings of the Indian National Science Academy, applied the MaxEnt machine-learning model to predict habitat suitability. Researchers analysed 9,757 occurrence records from the eBird citizen-science database and identified 117 confirmed presence points. Using nine bioclimatic variables, the model projected environmental changes under future warming scenarios.

Findings suggest a non-linear response to climate change. Between 2021 and 2040, habitat suitability may temporarily increase as lower montane regions become climatically favourable. However, by 2081–2100, high-suitability areas are projected to decline sharply, leading to range contraction and habitat fragmentation.

Specialised Species of the Sky Islands

The Nilgiri Wood Pigeon inhabits high-elevation wet evergreen and adjoining moist deciduous forests in the Nilgiris and Anamalai Hills of Tamil Nadu and Kerala. Isolated populations are also reported from the Biligirirangan Hills, Nandi Hills, and parts of northern Maharashtra. These high-altitude ecosystems, often described as “sky islands”, are marked by ecological isolation and high endemism.

The pigeon’s narrow elevational range, patchy distribution, and dependence on undisturbed forest canopy make it highly specialised. Such traits increase vulnerability to deforestation, plantation expansion, infrastructure growth, and climate change.

Up-Slope Shifting and Emerging Risks

Researchers highlight the phenomenon of “up-slope shifting”, where montane species move to higher elevations as temperatures rise. While moderate warming may expand niches temporarily, sustained warming ultimately compresses available habitat at mountain summits.

Although the species is currently listed as “Least Concern” by the IUCN, experts caution that this status is based largely on estimated distribution and assumed population size exceeding 10,000 mature individuals. Systematic field-based surveys on breeding ecology, population size, and habitat use remain limited. Projected warming could substantially reduce climatically suitable areas, potentially altering its conservation outlook.

Important Facts for Exams

• Nilgiri Wood Pigeon is endemic to the Western Ghats biodiversity hotspot.
• MaxEnt is a machine-learning tool used for species distribution modelling.
• “Sky islands” refer to isolated high-elevation ecosystems with high endemism.
• eBird is a global citizen-science platform for recording bird observations.

Need for Climate-Resilient Conservation

Scientists emphasise the need for climate-resilient conservation strategies for high-altitude forests of the Western Ghats. Long-term monitoring, systematic population surveys, and periodic reassessment of conservation status are recommended. Proactive planning that integrates climate vulnerability assessments with demographic studies will be crucial to ensure the persistence of this montane endemic species.