What is a mesopredator? A mesopredator (pronounced: may-so-predator) is a medium-sized predator located in the middle of a given food chain. A fisher (Pekania pennanti) or American marten (Martes americana) would be perfect examples of mesopredators. While they are quite ravenous hunters themselves, killing rodents, birds, rabbits and more; they still have many other predators of their own. Take a look at video below that shows both species on our nature trails attracted to a small pile of fish