Between locality variations in the seasonal patterns of dung beetles: the role of phenology in mitigating global warming effects

Abstract

1. Global warming may especially affect ectothermic insect species, making it necessary to forecast the capacity of these species to cope with climatic changes.

2. In this study, we use circular statistics to examine the seasonal plasticity of 32 dung beetle species in 17 localities of a mountain Iberian assemblage. We assume that the high variability between localities in the seasonal patterns for the same species suggests that seasonal plasticity could minimise the demographic effects of climate change on local populations.

3. Our results suggest that the populations of at least one-third of the dung beetle species could partially adapt to the effects of climate change by modifying their phenological occurrence, and that the degree of concentration of the seasonal occurrences is generally maintained independently of the locality. However, we have not detected clear seasonal pattern variations or a clear effect of environmental temperature on seasonal variations in around two-thirds of the studied species.

4. The dung beetle assemblages of this mountain region will experience deep changes in the future. Plasticity in seasonal patterns does not seem to be associated with species characteristics such as high-rank taxonomic identity, body weight, or geographical distribution. Only the general functional character of species would have some explanatory power. Endophagic Aphodiidae dung beetle species would be more capable than hypophagic species in mitigating the effects of climate change by modifying their phenological traits, whereas that Scarabaeidae hypophagic species may cope better with these climatic changes without having to change their seasonal activities.