Nature Notes: Spatiotemporal variation in the competitive environment, with implications for how climate change may affect a species with parental care

Abstract

AbstractBurying beetles of the genusNicrophorushave become a model for studying the evolution of complex parental care in a laboratory.Nicrophorusspecies depend on small vertebrate carcasses to breed, which they process and provision to their begging offspring. However, vertebrate carcasses are highly sought after by a wide variety of species and so competition is expected to be critical to the evolution of parental care. Despite this, the competitive environment forNicrophorusis rarely characterized in the wild and remains a missing factor in laboratory studies. Here, we performed a systematic sampling ofNicrophorus orbicollisliving near the southern extent of their range at Whitehall Forest in Clarke County, Georgia, USA. We determined the density ofN. orbicollisand other necrophilous species that may affect the availability of this breeding resource through interference or exploitation competition. In addition, we characterize body size, a key trait involved in competitive ability, for allNicrophorusspecies at Whitehall Forest throughout the season. Finally, we compare our findings to other published natural history data for Nicrophorines. We document a significantly longer active season than was observed twenty years previously at Whitehall Forest for bothN. orbicollisandNicrophorus tomentosus, potentially due to climate change. As expected, the adult body size ofN. orbicolliswas larger thanN. tomentosus, the only otherNicrophorusspecies that was captured in 2022 at Whitehall Forest. The other most prevalent interspecific insects captured included species in the families Staphylinidae, Histeridae, Scarabaeidae, and Elateridae, which may act as competitors or predators ofNicrophoruseggs and larvae. Together, our results indicate significant variation in intra- and interspecific competition relative to populations within theN. orbicollisrange. These findings suggest that the competitive environment varies extensively over space and time, which help to inform the role of ecology in the evolution of parental care in this species.