This is clearly unsustainable, they will all die off in the coming years.   I remember a while back they did this experiment on some island off of Alaska where they put some reindeer on the island with no wolves or any other natural predictors in a few year the reindeer population had grow exponentially and that winter when all of the vegetation on the island had been consumed they all starved just about every single one of them, and in the greater scope of things humans are no different if they do not control their population mother nature will control it for them and it will not be pleasant.  Sounds like an interesting concept. Now if we can only rid ourselves of Oxfam and the UN World Food Programme, we can finally channel the ghost of Charles Darwin and the Angel of Death and let them carry on the good work of mother nature in the turd-world. ;)