Pidgins and creoles develop where languages are in contact. They offer fantastic insights into questions such as language genesis and development when studied by participant observers in their field work. This chapter looks at pidgins and creoles from the ecological point of view and asks questions like the following: How do pidgins and creoles adapt to new environments? What is the impact of pidgins and creoles on language ecologies? Are pidgins and creoles a stabilizing or a destructive factor for existing linguistic diversity? Using many examples from his own field work, the author tries to answer these and other questions. One of his conclusions is that plausible answers can be given if (in contrast to the title) one explores what creolistics and ecolinguistics can learn from each other.