Answer:
Brown and black European rats have higher adaptive fitness.
Step-by-step explanation:
According to evolutionary theory, the adaptive fitness of an organism is the ability to successfully survive and reproduce in specific environmental conditions. In this case, the invasive species may show to have higher adaptive fitness and better performance compared to a local one because their individuals have, for example, a higher ability to avoid predators, to find food, to reproduce, etc., thereby these individuals will be selected by natural selection in order to occupy this ecological niche.