Integrating comparative functional response experiments into global change research

(a) Direct feeding interactions between a higher predator (the three‐spined stickleback, G asterosteus aculeatus ), intermediate consumers (native M ysis salemaai and invasive H emimysis anomala mysids), and a basal prey (the cladoceran, D aphnia magna ). Photo credits: G . aculeatus and H . anomala by S tephen P otts, M . salemaai and D . magna obtained from W ikimedia C ommons; (b) functional response of three native mysids (in blue) and three invasive mysids (in red); (c) functional response of three native mysids and one stickleback (in blue) and three invasive mysids and one stickleback (in red). Shaded areas are bootstrapped 95% confidence intervals. Adapted from Barrios‐O'Neill et al . ([Barrios‐O'Neill, D., 2014]).In Focus: Barrios‐O'Neill , D. , Dick , J.T.A. , Emmerson , M.C. , Ricciardi , A. , MacIsaac , H.J. , Alexander , M.E. & Bovy , H.C. ( 2014 ) Fortune favours the bold: a higher predator reduces the impact of a native but not an invasive intermediate predator . Journal of Animal Ecology , 83 , 693 – 701 . There is a growing appreciation for the importance of non‐consumptive effects in predator–prey interaction research, which can often outweigh the importance of direct feeding. Barrios‐O'Neill et al . ([Barrios‐O'Neill, D., 2014]) report a novel method to characterize such effects by comparing the functional response of native and introduced intermediate consumers in the presence and absence of a higher predator. The invader exhibited stronger direct feeding and was also more resistant to intimidation by the higher predator. This experimental framework may be incorporated into mainstream global change research, for example, to quantify the importance of non‐consumptive effects for the success or failure of biological invasions.