No Regrets, Page 27

  The number of lions that can be living on Earth at any time is linked to the number of lycans that are alive. If that number plummets precipitously, there is a sudden die off. Lion powers depend on the number of lycans alive (the 'power pool'), but there are also some lion abilities that depend on the number of lions alive. These abilities are inversely proportional to population, i.e. fewer lions, more abilities.