each September the Norse had to make the agonizing decision how many of their precious livestock to cull, basing that decision on the amount of fodder available and on their guess as to the length of the coming winter. If they killed too many animals in September, they would end up in May with uneaten hay and just a small herd, and they might kick themselves for not having gambled on being able to feed more animals. But if they killed too few animals in September, they might find themselves running out of hay before May and risk the whole herd starving.
