Evisceration residues from hunted roe deer as a resource for necrophagous insect fauna in the Black Forest, Germany: a preliminary study

Abstract

Carrion of wild ungulates is an important resource for microbes, invertebrates and vertebrates, and affects local plant communities and soils. Most wild ungulates in central Europe, however, are intensely hunted and removed from the ecosystem, thus not available as carrion. This study explores the use of evisceration residues as a resource by necrophagous insects in a temperate mountainous forest in Germany. We experimentally compared the relative abundance of necrophagous insects between sites of caged roe deer carcasses and evisceration residues of roe deer using pitfall‐traps. While evisceration residues were used by necrophagous insects, significantly more individuals were sampled at entire deer carcasses; when corrected for biomass, however, no significant difference in abundance for Coleoptera groups was found. Overall, evisceration residues were used earlier and for a shorter period than entire deer carcasses. Leaving evisceration residues on site where game animals are obtained might help maintain specialized necrophagous insect communities, although their ecological role cannot completely replace that of whole carcasses of wild ruminants.

Use of viscera from hunted roe deer by vertebrate scavengers in summer in central European mountainous mixed forest

“…The feeding activity per carrion sample decreased over the course of the experiment. This indicates that viscera samples were depleting and/or rendered unattractive as a resource for vertebrate scavengers through decay, microbes, and consumption by invertebrates (Janzen 1977, Schwegmann et al 2022. Similar to our results, previous studies detected very Table 1.…”

“…Additionally, we observed that a range of insectivorous mammal and bird species were also attracted to carrion and used it as a source of prey. Our studies show that a wide range of vertebrate (this study) as well as invertebrate (Schwegmann et al 2022) taxa use evisceration residues directly or indirectly as a resource. Carrion subsidies from hunting might help maintaining vertebrate and invertebrate scavenging communities as well as scavenging as ecosystem function.…”

“…The feeding activity per carrion sample decreased over the course of the experiment. This indicates that viscera samples were depleting and/or rendered unattractive as a resource for vertebrate scavengers through decay, microbes, and consumption by invertebrates (Janzen 1977, Schwegmann et al 2022). Similar to our results, previous studies detected very few scavenging events by vertebrates around after 20 days past exposure, indicating over the warm period most carrion will be depleted after this time (Inagaki et al 2022, Mctee and Stone 2022).…”

“…Data are available from the Dryad Digital Repository: https:// doi.org/10.5061/dryad.q573n5tpp (Schwegmann et al 2023).…”

“…Currently, it is unclear how much carrion in space and time and in which quality is needed to maintain native necrophagous fauna and corresponding ecosystem services (Barton et al 2019). In a prior study, we found that roe deer Capreolus capreolus viscera left from hunting could in part functionally replace ungulate carcasses as a resource for necrophagous insects (Schwegmann et al 2022). However, in the previous study, we placed the viscera samples in metal cages, which excluded vertebrate scavengers from consuming roe deer viscera before invertebrates could make use of this resource.…”