Final answer:
New Caledonian crows have the potential to survive in Europe due to their high adaptability and problem-solving abilities, but their impact on the ecosystem and survival would be influenced by various ecological factors.
Step-by-step explanation:
Considering the adaptive nature of New Caledonian crows and the successful establishment of other non-native birds in new environments, it's plausible that New Caledonian crows could potentially survive on their own in Europe. Factors that could weigh on their survival include their extraordinary problem-solving skills and ability to use tools, which might help them in exploiting new food sources. However, their survival would also depend on various ecological factors, such as the availability of suitable habitat, presence of competitors and predators, and the climate's similarity to their native habitat.
Previous studies on avian introductions by humans, like those discussed by Carrete and Tella (2008), suggest that bird species with particular life-history traits and higher adaptability have historically managed to establish populations outside their native ranges. Yet, this is not without potential ecological impacts, such as competition with native species and the spread of diseases, among others.
Overall, while New Caledonian crows may possess the intrinsic abilities to survive, the broader ecological implications on the native fauna and flora in Europe must be carefully considered before any such introduction could take place.