Sex, size, and prey caloric value affect diet specialization and consumption of an invasive prey by a native predator.

Escaping the control of natural enemies is thought to heavily influence the establishment success and impact of non-native species. Here, we examined how the profitability of alternative prey in combination with the presence of a competitor and predator aggressive behavior explain individual differences in diet specialization and the consumption of the invasive green porcelain crab by the native mud crab predator Results from bomb calorimetry estimates show that invasive has high caloric value relative to alternative native prey. Laboratory assays indicated that specialization and consumption of invasive was mostly exhibited by large, female , but the presence of a competitor and predator aggressiveness did not influence diet and the consumption of Thus, intrinsic factors (e.g., sex and body size) seem to explain consumption of and dietary specialization in , more generally. Although there are still many predator individuals that do not consume , the proportion of individuals that have begun to specialize on suggests that for some, it has become more profitable relative to alternative native prey. Given the high caloric value of , we suggest that it is likely that differences in the cost of its consumption, including attack, capture, and handling times relative to alternative prey, determine its net profitability to individual predators.