I was not using the fisherman to explain what capitalism is, you did.

Marmots for sure accumulate nuts. No doubt about it. Would that accumulation enhance productivity? Well yes cause they have food that they can use in periods where there is not much around. So yes. They are capitalists in your definition.

Accumulation of capital to enhance productivity.

Also this is a super vague definition which is not exclusive to capitalism. Managing capital is banned in communism. Is just the way that the leading class uses the force class which is sort of enslaving.

Are you not part of the working class?

Are you a capital owner and earn your capital on the job other people do?