Abstract: When surveying colonies of cliff-nesting seabirds that are not safely visible from cliff tops, researchers may choose between hand-held vessel-based digital photography and drone imagery (uncrewed aerial vehicles, UAVs) to assess colonies on seaward-facing cliffs. Both methods can produce more accurate and auditable counts than traditional land-based and vessel-based surveys. Vessel-based surveys can be costly, weather-dependent, and pose safety risks to personnel, whereas UAVs provide a faster and safer alternative, albeit also reliant on relatively low wind speeds. This study compared counts of guillemot ( Uria aalge), razorbill ( Alca torda), and kittiwake ( Rissa tridactyla) from UAV- and vessel-based digital imagery collected along Scotland’s East Caithness Cliffs in June 2025. Using generalized linear mixed models, results suggest that guillemot counts were 35% higher in UAV imagery, and there was no significant difference for kittiwake or razorbill. These findings indicate that UAV-based surveys can enhance detection of species nesting on broad cliff ledges, though differences are species-specific. This study also provides the first correction factor to support integration of UAV data into long-term seabird monitoring programs in Scotland.