Sasquatch,
   Great story, reminds me of "The way things work" with the mammoths.  Anyway, I don't understand how the lowering consumption of sasquatch diet (except for the energy gatherers) changes EROI. If corn ethanol has a different EROI than gas hydrogen or whatever, running it through a prius or a hummer does not change that.  Also if food is low could they not kill the monkeys and eat them also reducin mongo nut competition. Maybe have the space ship import plastic flowers and they would not have to pick those either.  Just kidding.
Matt