LAUSR

Abstract Over the last century, numbers of wild tigers (Panthera tigris) have crashed, while human populations have boomed. Here we investigate future trajectories of human population within tiger range through analysis of the shared socio-economic pathways (SSPs). These five pathways describe urban, rural and total population distributions by decade through 2100, based on plausible but contrasting scenarios of economic, education, migration, and urbanization policy. In 2010 approximately 57 million people lived in regions defined as “tiger conservation landscapes” (or TCLs); 8% of sympatric people lived in towns and cities that occupied 4% of tiger range. We show that tigers could share these same geographies with as few as 40 million (30% decline compared to 2010) or as many as 106 million people (an increase of 85%) by 2100. Those populations could be as much as 64%, or as little as 17%, urbanized, depending on the pathway. Urban areas are likely to expand, displacing between 6 and 22% of tiger's current range, depending on how urban growth is managed. Human population density thresholds compatible with tigers vary by region, from 140 persons/km2 in the Indian subcontinent, to 10 persons/km2 in the Russian Far East and northern China. SSP3, a future where nations indulge regional rivalries, would make conservation more difficult, whereas SSP1, with a focus on well-managed urbanization and education, could help relieve pressures. Tigers are a conservation-reliant species and will likely remain so through the 21st century, therefore we suggest coupling continued site-level protection with efforts to develop constituencies for conservation in Asia's burgeoning cities.