Assessing the climate change impact on the habitat suitability of the range-restricted bird species (Catreus wallichii) in the Indian Himalayan ecosystem

Abstract

Climate change profoundly impacts ecosystems' function and composition, changing living organisms' habitats. The Indian Himalayan ecosystem (IHE) is particularly susceptible and vulnerable to the effects of climate change. However, our understanding of how climate change affects the habitats of range-restricted and vulnerable avifauna in the IHE still needs to be improved. Hence, we employed ensemble species distribution modelling to examine the potential habitat shift of the cheer pheasant (Catreus wallichii) under climate change scenarios (representative concentration pathways, RCPs) i.e. RCP 4.5, RCP 6.0 and RCP 8.5) by 2050 and 2070. The study revealed a noticeable expansion of climatically suitable habitats, indicating a shift towards higher altitudes that would become more favourable and suitable under future climates. The model predicted an area of very highly suitable habitat (1247.4 km²), followed by highly suitable (2747.9 km²), moderately suitable (4002.3 km²), low suitable (4952.2 km²) and rarely suitable (4236 km²) in the current scenario. The projection of larger areas was falling into the "no change", followed by the "high suitable" and "low suitable" classes, for both the years 2050 and 2070 across all the RCPs. Furthermore, the projections indicated a consistent trend of increasing suitability for the cheer pheasant at higher elevations and a decline at lower elevations across RCPs for 2050 and 2070. Moreover, the mean diurnal temperature range was identified as the crucial driving factor, followed by isothermally and precipitation, influencing the species' shift towards suitable habitats at higher altitudes. The study can aid policymakers in developing effective conservation strategies to protect Himalayan range-restricted bird species in the face of climate change.

Keywords: Biodiversity conservation and management; Cheer pheasant; Climate change; Ensemble species distribution modelling; Indian Himalayan Ecosystem; Range-restricted bird species.