Madison Thurber, Virginia Tech

Infectious diseases pose a significant threat to wildlife conservation by driving population declines, fragmentation, and local extinctions. These risks are intensifying as anthropogenic pressures alter ecosystems, yet disease impacts often remain difficult to detect, particularly when they interact with additional stressors or novel pathogens. Understanding how ecological and landscape factors shape disease dynamics is therefore critical for effective wildlife management. Sarcoptic mange (Sarcoptes scabiei) is a highly contagious disease affecting domestic and wild mammals, and in black bears (Ursus americanus) it can cause severe clinical symptoms and mortality. Mange cases have increased across the mid-Atlantic over the past decade, but the demographic impacts of infection, and the landscape factors influencing disease occurrence and spread, remain poorly understood. Variation in host density and habitat connectivity likely plays a key role in shaping outbreak severity and spatial extent. We examine relationships among black bear density, landscape connectivity, and mange occurrence in a mange-affected and a mange-unaffected region of Virginia. Using noninvasive genetic sampling from hair snares, spatial capture–recapture (SCR), and an SCR ecological distance model, we estimate black bear density and functional connectivity across contrasting disease settings and between years. During 2024 and 2025, we deployed a total of 160 hair snares across both regions and collected 3,656 hair samples. Genotyping and SCR analyses are ongoing, and we present preliminary first-year results from 2024. By linking host density and connectivity across space and time, this research will improve understanding of mange dynamics in black bears and inform disease surveillance, harvest management, and conservation strategies across the mid-Atlantic.