PS 8-90 - Scavenging dynamics of reptile and amphibian carrion in a temperate ecosystem

Monday, August 7, 2017
Exhibit Hall, Oregon Convention Center
Erin Foster Abernethy1, Kelsey Leigh Turner2, James C. Beasley2 and Olin E. Rhodes Jr.3, (1)Integrative Biology, Oregon State University, (2)Warnell School of Forestry, University of Georgia, (3)Savannah River Ecology Lab, University of Georgia
Background/Question/Methods

Scavenging is an influential ecosystem process, providing many weak, but stabilizing food web links. Reptiles and amphibians, i.e. herpetofauna, with their large biomass and complex life cycles are important vectors of nutrients between aquatic and terrestrial systems and provide a valuable resource to scavengers, likely contributing to food web stability. There are limited data on the fate of herpetofauna carrion, and thus it is unknown how such carcasses are incorporated into food webs or how habitat and carcass characteristics influence which scavengers acquire these resources. We used camera traps to determine the proportion of placed reptile and amphibian carcasses (lizards, salamanders, frogs, and toads) scavenged by vertebrates and invertebrates in two different habitats (wetland and upland) during the spring in the Southeastern USA. We then used log-linear models to evaluate the impact of habitat and carcass type on scavenging.

Results/Conclusions

Vertebrates removed 20.1% of all herpetofauna carcasses in both habitats, with the remaining carcasses primarily scavenged or removed by invertebrates (79.9%). We determined that habitat, rather than carcass type, was most influential in determining whether a vertebrate or invertebrate scavenged a carcass, with vertebrates able to scavenge more carcasses in wetland than in upland areas. In less than 2 days, 86.2% of all carcasses in both habitat types were completely scavenged, and carcasses in wetlands were removed more quickly, suggesting intense competition between vertebrates and invertebrates. Additionally we observed low vertebrate scavenger richness, which we attribute to high invertebrate activity in the spring and the small size of the herpetofauna carcasses (<100g). We identified the scavenging pathways along which herpetofauna are incorporated into the ecosystem and the factors which influence those pathways, suggesting the extent and spatial scale of this resource’s influence on food web connections and consequently food web and ecosystem stability.