Climate-driven habitat decline and fragmentation of a South Asian grassland specialist: ensemble projections for Jerdon’s Babbler under future scenarios
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引用次数: 0
Abstract
Climate change poses significant threats to biodiversity, particularly for habitat-specialist species like Jerdon’s Babbler (Chrysomma altirostre), a grassland-dependent passerine of South and South-east Asia. This study employed an ensemble species distribution modelling (SDM) approach using 12 algorithms and climatic-elevation predictors to assess the current and future habitat suitability for Jerdon’s Babbler under three Shared Socioeconomic Pathway (SSP) scenarios: SSP1-2.6, SSP2-4.5, and SSP5-8.5, across four future timeframes (2021––2100). Occurrence data (n = 79) were compiled from field surveys and secondary sources, filtered to reduce spatial autocorrelation. Environmental predictors were selected through Pearson correlation and permutation importance methods, with elevation, grassland proximity, and thermal variables emerging as key determinants of distribution. Among individual models, Random Forest and Gradient Boosting Machine outperformed others (TSS > 0.88), and ensemble models achieved perfect calibration (TSS and ROC = 1.00).
Projected distributions indicate severe range contraction under all future scenarios, with habitat loss exceeding 80 % by 2081–2100 period under SSP1-2.6 and near-total collapse under SSP5-8.5. Subspecies-specific centroid analyses showed varying climate sensitivity, with Indian and Burmese populations shifting over 900 km, while Indo-Bangladesh populations remained largely static. Despite the potential persistence of refugia in northeastern India and Nepal under low-emission pathways, model projections underscore the urgency of targeted conservation strategies, including grassland restoration, climate-resilient corridors, and ex-situ conservation in high-risk areas. This study highlights the critical vulnerability of grassland birds to climate change and the value of ensemble SDMs for anticipatory conservation planning.
期刊介绍:
The Journal for Nature Conservation addresses concepts, methods and techniques for nature conservation. This international and interdisciplinary journal encourages collaboration between scientists and practitioners, including the integration of biodiversity issues with social and economic concepts. Therefore, conceptual, technical and methodological papers, as well as reviews, research papers, and short communications are welcomed from a wide range of disciplines, including theoretical ecology, landscape ecology, restoration ecology, ecological modelling, and others, provided that there is a clear connection and immediate relevance to nature conservation.
Manuscripts without any immediate conservation context, such as inventories, distribution modelling, genetic studies, animal behaviour, plant physiology, will not be considered for this journal; though such data may be useful for conservationists and managers in the future, this is outside of the current scope of the journal.