Climate-driven decline in the habitat of the endemic spiny babbler (Turdoides nipalensis)

Climate change could amplify the extinction risk of endemic species, and the risk is even greater for species occupying high elevations and mountain ranges. In this study, we assessed the climatically suitable habitat of the only endemic Nepalese bird species, the spiny babbler (Turdoides nipalensis), and predicted the extent of the future (2050 and 2070) habitat of this species under two climate change scenarios (SSP2-4.5 and SSP5-8.5). We used georeferenced occurrence points alongside ecologically meaningful climatic and topographic variables to develop an ensemble suitable habitat model using different species distribution modeling algorithms in BIOMOD2. We identified 22,488.83 km(2) (15%) of Nepal's total land area as suitable habitat for this endemic species, where the nonprotected regions incorporated the largest extent of suitable habitat (88%), with a majority of this suitable area within the central Mid-Hill region. Under the SSP2-4.5 scenario, 21.58% and 34.08% of the current suitable habitat range are projected to be lost by 2050 and 2070, respectively. Whereas under the SSP5-8.5 scenario, our projections suggest that 40.45% and 52.18% of habitat will be lost by 2050 and 2070, respectively. Habitat suitability increased with a rise in warmest quarter precipitation (above 1000 mm), coldest quarter precipitation between 50 and 100 mm, and warmest quarter temperature between 20 and 30 degrees C. Given our results, it is crucial to review the conservation policy of nonprotected areas and formulate a spiny babbler-specific conservation action plan with a special focus on protecting their primary habitat in human-dominated landscapes and nonprotected areas.