Climate change could restrict habitat availability for Western Ghats birds such as The Nilgiri Wood Pigeon, warn researchers

Climate change could lead to the habitat of Western Ghats endemic species such as the Nilgiri Wood Pigeon (Columba elphinstonii) become extremely limited to a few isolated pockets by the end of the century, a recent research paper warns.

The study, titled “Biogeography and habitat suitability of the Nilgiri Wood Pigeon using MaxEnt”, published in the “Proceedings of the Indian National Science Academy” used MaxEnt, a machine-learning method to model habitat suitability for species, and estimates that the Nilgiri Wood Pigeon (NWP) faces a bleak future marked by “sharp declines in high-suitability areas and marked range contractions.”

The natural habitat of the pigeon comprises high-elevation wet evergreen and adjoining moist deciduous forests, particularly in regions such as The Nilgiris and Anamalai Hills in Tamil Nadu and Kerala. Isolated populations are also reported from locations such as the Biligirirangan Hills, Nandi Hills, and northern Maharashtra.

These ecosystems, often described as “sky islands”, are recognised for their high levels of endemism and ecological specialisation. The pigeon’s restricted elevational range, patchy distribution, and dependence on undisturbed canopy conditions make it a highly specialised species, the authors of the paper — Phillmon Smart Edward, Jeyasubashini Reghupathikannan, and Arockianathan Samson — note adding that Western ghats specialists such as the NWP are particularly vulnerable to anthropogenic pressures such as deforestation, agricultural and infrastructure expansion, plantation development and climate change.

The researchers used 9,757 occurrence records for the species from the eBird database – a citizen-science project that allows users to record bird sightings. Using the occurrence records, the researchers identified 117 presence points for the species and modelled environmental projections using nine bioclimatic variables.

The model predicts that while habitat suitability for the species would initially witness an increase, due to lower montane areas becoming more suitable for the species between the years 2021 to 2040, that this trend would begin reversing by 2081-2100, with “sharp declines in high suitability areas.”

“This non-linear response emphasises that while moderate warming may temporarily benefit cold-adapted montane species by expanding their niche upward, continued warming leads to a net contraction of available habitat,” the authors stated.

Phillmon Smart Edward, one of the authors of the paper, told The Hindu the Nilgiri Wood Pigeon was one of 16 species of birds occupying mid and high-elevation parts of the Western Ghats, which are highly susceptible to climate change.

“We decided to study the wood pigeon to understand the phenomenon of ‘up-slope shifting’ where species move higher up the mountain slopes due to climate change causing their preferred habitats and food sources further up the mountains,” said Mr. Edward.

Arockianathan Samson, from the Bombay Natural History Society and another author of the paper, said that the study highlighted the need for climate-resilient conservation strategies for the high-altitude forests of the Western Ghats to protect not just the Nilgiri Wood Pigeon but also other endemic species that could all be potentially affected by climate change in the coming decades.

“Although the species was recently down-listed to “Least Concern” by the IUCN, primarily due to its broad distribution and the assumption that its population exceeds 10,000 mature individuals, this threshold has not been validated through systematic ground surveys.

Distributional extent and habitat suitability modelling, while informative, cannot substitute for rigorous demographic assessments,” he said adding that projected warming scenarios could “substantially reduce climatically suitable habitats in the long term.”

Jeyasubashini Regupathikannan said that more field based ecological studies are essential to accurately assess the conservation status of this elusive montane bird. Systematic surveys on population size, breeding ecology, and habitat use will help clarify its long-term viability and conservation strategies for high elevation forests of the Western Ghats.

“While the species may not currently meet thresholds for a threatened category, projected habitat compression under future climate regimes introduces emerging risks that are not fully reflected in its present status,” added Mr. Samson who recommended systematic population surveys, long-term monitoring, and periodic reassessment of its conservation status, integrating both current distributional data and future climate vulnerability for the species.

“Ensuring the persistence of this Western Ghats endemic will require proactive planning that anticipates ecological shifts rather than reacting to population collapse after it occurs,” he noted.

Published – February 27, 2026 10:32 pm IST