Scavenging along an ecological interface: utilization of amphibian and reptile carcasses around isolated wetlands
Article
Abernethy, EF, Turner, KL, Beasley, JC et al. (2017). Scavenging along an ecological interface: utilization of amphibian and reptile carcasses around isolated wetlands
. 8(11), 10.1002/ecs2.1989
Abernethy, EF, Turner, KL, Beasley, JC et al. (2017). Scavenging along an ecological interface: utilization of amphibian and reptile carcasses around isolated wetlands
. 8(11), 10.1002/ecs2.1989
Scavenging is an influential ecosystem process, providing many weak, but stabilizing food web links. Amphibians and reptiles (i.e., herpetofauna) utilize land/water interfaces and can have large biomasses concentrated here, making them important vectors of nutrients between aquatic and terrestrial systems and a valuable resource to scavengers. 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 experimental amphibian and reptile 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. Vertebrates removed 19.8% of all herpetofauna carcasses in both habitats, with the remaining carcasses removed by invertebrates (80.2%). We used log-linear models to evaluate the impact of habitat and carcass type on scavenging. We determined that habitat, but not carcass type, was 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 two 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 (<100 g). We identified the scavenging pathways along which herpetofauna are incorporated into the food web and the factors that influence those pathways, suggesting the large extent and spatial scale of this resource’s influence on food web connections and consequently food web and ecosystem stability.
