Impacts of high density of sika deer (Cervus nippon yesoensis) on dung beetle community

Abstract

We assessed the impact of sika deer (Cervus nippon yesoensis) density on the abundance, diversity and species composition of forest dung beetle communities. We used baited-traps to collect dung beetles in habitats with two different sika deer densities near Lake Toya, Hokkaido, Japan; Nakajima Island (high-density) and the nearby lakeshore forest (low-density). Overall, our results showed that dung beetle abundance was associated with higher deer density. Although differences in dung beetle species richness, diversity index and beta diversity were not statistically significant among deer densities. NMDS analysis showed that dung beetle community composition did vary with deer density. Our results indicate that, where deer density is high, the dung beetle community characterized by grassland species, including Caccobius jessoensis, Aphodius pusillus and A. rectus. Conversely, where deer density is low, the dung beetle community comprises forest species such as Phelotrupes laevistriatus. Our study suggests that deer density strongly influences dung beetle species abundance via the volume of deer dung. Additionally, we show that forest dwelling dung beetle species give way to grassland dwelling species at higher deer densities.