Efficiency and composition of vertebrate scavengers at the land-water interface in the Chernobyl Exclusion Zone

Abstract

Scavenging increases the connectivity of food webs yet scavenging links between adjacent ecosystems are poorly characterized. Here we explored the movement of aquatic carrion into terrestrial food webs by vertebrate scavengers across two habitat types in the Chernobyl Exclusion Zone (CEZ). We used motion activated cameras to monitor experimentally placed fish carcasses to quantify the composition and efficiency of vertebrate scavengers of canal and river communities in the CEZ. We conducted 83 trials that were scavenged by 10 mammalian and 5 avian species. Species diversity, percentage consumed, scavenging efficiency, and time until scavenged differed between canal and river trials. Mesocarnivores were the predominant scavengers in both habitats, and we observed greater scavenger efficiency and higher diversity (but lower richness) among river trials. Variation in scavenging among habitats was attributed to the interplay of higher detection rates in the river habitats and differences in scavenger community, as canals intersected a greater diversity of habitat types. Our data suggest the CEZ supports a highly diverse and efficient vertebrate scavenging community with important implications for the redistribution of scavenging-derived nutrients and the connectivity of adjacent ecosystems. Future studies should focus on species-specific patterns of nutrient redistribution and ultimate carcass deposition sites to further our understanding of the mechanisms connecting aquatic and terrestrial systems via scavenging of aquatic nutrients by terrestrial scavengers.