<p>Deforestation and forest degradation are among the most consequential anthropogenic pressures on terrestrial biodiversity. Their ecological effects extend beyond the direct removal of vegetation to include habitat fragmentation, edge effects, deterioration of microclimatic conditions, disruption of trophic interactions, reduction of breeding and feeding resources, population isolation, and loss of landscape connectivity. This narrative review synthesises peer-reviewed evidence, with emphasis on literature published between 2012 and 2022, on the relationships among forest loss, fragmentation, and wildlife habitat, with particular reference to India and Jharkhand. Global assessments show that forest cover alone is an incomplete indicator of ecological condition: forests can remain mapped as forest while experiencing structural degradation, edge effects, and declining connectivity. A global synthesis found that about 70% of remaining forest lies within 1 km of an edge and that fragmentation can reduce biodiversity by 13&ndash;75% while impairing key ecosystem functions, with effects greatest in the smallest and most isolated fragments and magnifying over time. Evidence from India demonstrates comparable landscape-scale risks. Historical analysis of Asian elephant ranges documented a 21.49% loss of forest cover between 1930 and 1975, a further 3.19% loss between 1975 and 2013, and a 39.6% reduction in core forest area across the full period. In Jharkhand, geospatial analysis of Dalma Wildlife Sanctuary quantified a measurable shift of forest away from core toward perforated, edge, transitional, and patch classes, with about 70% of the sanctuary showing an increasing trend in forest-fire severity as fragmentation intensified. Studies from the Saranda landscape further demonstrate forest stress in mining-associated environments. The evidence supports a shift from area-based forest accounting toward landscape-scale conservation that integrates habitat quality, ecological connectivity, species movement, mining and infrastructure pressures, and long-term wildlife monitoring. Protecting intact forests, restoring degraded native habitat, safeguarding functional corridors, and integrating remote sensing with field ecology are central priorities for biodiversity conservation in India and Jharkhand.</p>