Traits retained in arthropod corpses influence the scavenging behavior of invertebrate scavengers

Unveiling the enigmatic processes underlying the rapid disappearance of arthropod corpses in nature is not only fascinating but also essential for understanding their ecological fate. Functional traits retained in freshly dead arthropods may influence their consumption by invertebrate scavengers. To validate this idea, we conducted a field trapping survey using four types of baits (arthropod corpses, yak carrion, yak dung, and horse dung) to investigate the attraction of arthropod corpses to necrophagous beetles in a Tibetan alpine meadow, complemented by a laboratory experiment to further examine the scavenging behavior of three necrophagous beetle species (i.e., Thanatophilus rugosus, Nicrophorus sinensis, and Nicrophorus investigator) on 25 species of dead arthropods. Results show that arthropod corpses can attract necrophagous beetles, albeit with lower species richness and abundance compared to yak carrion in the Tibetan alpine meadow. All the three necrophagous beetle species exhibited a preference for arthropod corpses with higher internal water content, lower exoskeleton content, and intermediate body size. In addition, the beetles preferentially consumed the abdomen with lower exoskeleton content to the thorax and head during partial consumption. These findings suggest that internal water content, exoskeleton content, and body size of arthropod corpses significantly influence the scavenging behavior of necrophagous beetles, thereby highlighting the importance of animal functional traits in shaping predator-prey interactions within scavenger communities.