Interplay of succession and seasonality reflects resource utilization in an ephemeral habitat

Ephemeral habitats such as dung pats provide an abundance of resource for their inhabitants. Despite the potentially severe competition, they host a very diverse array of species. The species coexistence is probably facilitated primarily by separation in time. Here we present a first complex study of such temporal segregation, along successional and seasonal gradients, focused on a complete community of coprophilous beetles from Central Europe. Specifically, both coprophagous and predatory species were studied. In addition to the successional age of dung pats we measured the decline of dung moisture. We captured 39, 627 beetles belonging to 85 species using artificially created dung pats in a sampling design robust against short-term variation in weather conditions. The optima of late successional species were shifted toward earlier days of succession and the whole course of succession took fewer days when compared to studies from Northern Europe (9 versus 14 days). This indicates constancy of the species successional sequence, but temporal plasticity when later successional species reach their optima. Our results suggest that the coprophagous species are separated successionally according to the development time their larvae spent in the original dung pat. The later in the succession, the more time the larvae live freely in the dung pat. The same phenomenon applies for the seasonal separation, where the latter are species or guild in succession the more effectively they are separated seasonally. The predatory species are separated both seasonally and successionally by their size with smaller predators in latter phases in both temporal aspects.