Encounter rates of carnivores with prey are dependent on spatial and temporal overlap, and are often highest with their preferred prey. The Critically Endangered Sumatran tiger Panthera tigris sumatrae is dependent on prey populations, but little is known about its prey preferences. We collected camera-trap data for 7 years (2010–2016) in Bukit Barisan Selatan National Park, Sumatra, to investigate spatial and temporal overlap of tigers with potential prey species. We also developed a novel method to predict predator–prey encounter rates and potential prey preferences from camera-trap data. We documented at least 10 individual tigers, with an overall detection rate of 0.24 detections/100 trap nights. Tigers exhibited a diurnal activity pattern and had highest temporal overlap with wild boar Sus scrofa and pig-tailed macaques Macaca nemestrina, but highest spatial overlap with wild boar and sambar deer Rusa unicolor. We created a spatial and temporal composite score and three additional composite scores with adjustments for the spatial overlap and preferred prey mass. Wild boars ranked highest for all composite scores, followed by sambar deer, and both are known as preferred tiger prey in other areas. Spatial and temporal overlaps are often considered as separate indices, but a composite score may facilitate better predictions of encounter rates and potential prey preferences. Our findings suggest that prey management efforts in this area should focus on wild boar and sambar deer, to ensure a robust prey base for this Critically Endangered tiger population.

Information about the spatial distribution of bycatch species and their spatial overlap with the target species is essential for fisheries management. The present study used fishery-dependent data (vessel monitoring systems, logbooks and official daily landings) to study the spatial distribution and overlap between black scabbardfish Aphanopus carbo and leafscale gulper shark Centrophorus squamosus taken by the longline fishery operating off mainland Portugal. The geostatistical method kriging was applied to estimate the distribution of the leafscale gulper shark in relation to black scabbardfish and thus assess the impact of the fishery on the leafscale gulper shark. Results indicate that in fishing grounds where the black scabbardfish is more abundant, the relative occurrence of deepwater sharks is reduced. These findings have implications for alternative management measures to be adopted in this particular fishery, particularly where it concerns the minimization of deepwater shark bycatch.