Final answer:
Elephants in the wild are an example of a common resource since their existence in the ecosystem translates into economic benefits from eco-tourism and they are threatened by issues like poaching and habitat loss.
Step-by-step explanation:
A common resource is a type of public good that is characterized by being non-excludable but rivalrous, meaning individuals cannot be effectively excluded from its use, and one person’s use diminishes another person's ability to use it.
Elephants in the wild are an example of a common resource because they inhabit ecosystems that provide significant income from eco-tourism and are subject to issues such as poaching. This scenario corresponds to the 'tragedy of the commons', where individuals deplete a resource due to their immediate self-interest, undermining the long-term availability of that resource.
National parks and game preserves offer protection for elephants from poaching and habitat loss. However, even within these protected areas, poaching is a significant problem, and human population growth continues to stress the habitats of these and other animals like gorillas and chimpanzees.