Temporal niche partitioning in two sympatric species of burying beetles

Background/Question/Methods

Species that coexist and use similar resources often partition resource use along at least some niche axes to minimize competition and maintain coexistence.  Species may differ in times of activity, food characteristics, breeding periods, or habitat use. Two species of burying beetle (Nicrophorus guttula and N. marginatus) coexist in valleys of central Utah, but little is known about their biology or interaction with one another. To test for niche partitioning, we collected beetles of both species from the field and established a reproducing lab population.  We tested for differences in daily activity period between the two species and predicted that the two species would be active at different times of day. Using males and females of both species from our population, we observed and recorded the activity of the beetles for twenty-four hours (one observation per hour) over a three day period in a laboratory setting.

Results/Conclusions

Daily activity periods differed between the two species, suggesting that the species may partition resources based on time of use.  Both N. guttula and N. marginatus utilize similar resources (small vertebrate carcasses) and may experience reduced interspecific competition by partitioning time of day of resource use.  In future work we will compare other potential niche axes between these two species to determine conditions of coexistence of potential competitors.