Warming effects on dung beetle ecosystem services: Brood production and dung burial by a tunnelling dung beetle, Onthophagus taurus (Coleoptera: Scarabaeidae), is reduced by experimental warming

Dung beetles provide economically valuable ecosystem services to agriculture. Dung beetles are also sensitive to climate change, which may impact on the services that they provide. Using climate-controlled chambers, we investigated the potential effects of climate change on the performance of a tunnelling dung beetle, Onthophagus taurus. Over two trials, we exposed beetles to a +0 degrees C, +2 degrees C or +4 degrees C increase in diurnally fluctuating field recorded temperatures and measured survival, pat departure, reproduction (brood number and size) and dung burial by beetles. Temperature treatment did not affect pat departure behaviour. Relative to the control +0 degrees C chambers, beetle survival was higher in the +2 degrees C chambers, but there was no difference in survival between the +0 degrees C and +4 degrees C chambers. In Trial 1, brood number was reduced in both the +2 degrees C and +4 degrees C chambers, relative to the +0 degrees C chambers. In Trial 2, brood number was significantly reduced relative to control chambers in the +2 degrees C chambers only. Temperature did not affect brood size. Across temperature treatments, there was a significant, positive relationship between brood number and dung burial. However, trends in brood production with temperature were not mirrored by dung burial; the only reduction in dung burial was found in the warmest treatment of Trial 2. Our results suggest that initially, warming may not substantially reduce dung burial by O. taurus; however, ecosystem services may be impacted if lower brood production eventually reduces beetle numbers. Studies such as ours identify the vulnerabilities of ecosystem service providers to climate change and in doing so are an essential first step in the management of ecosystem services under future warming.