Establishing silphids as an iDNA tool: Diet analysis through genetics

Invertebrate DNA (iDNA) is a fairly well-known method for mammalian biodiversity surveys that analyzes invertebrate diets. Common groups for this method are blood-feeding invertebrate families such as ticks, flies, or mosquitoes, but Silphid beetles have yet to be used for iDNA in scientific literature before now. Silphids have two major family groups: burying beetles (Nicrophorinae) and carrion beetles (Silphinae). Both require carrion for reproduction, with burying beetles needing small carcasses, such as small mammals, and carrion beetles being more generalists. Therefore, Silphids have potential for noninvasive mammalian biodiversity surveys. A 2019 summer field season was conducted to determine viability of Silphids for iDNA. We successfully identified multiple vertebrate species with a small preliminary dataset, including small mammal species, carnivores, an avian individual, and potential bait consumption, proving viability of Silphid iDNA and prompting larger scale 2021 and 2022 field seasons that included a mark recapture component for Silphids to analyze community composition and look at different populations in a minimally invasive manner. The potential applications for targeted small mammal biodiversity and broad mammal biodiversity surveys with Silphid beetle diets is an exciting step forward. Their specialization on ubiquitous, rare, or difficult to handle small mammal species makes them a valuable iDNA tool.