A Factor of EvolutionMutual Aid: A Factor of Evolution Peter Kropotkin 1902 Chapter 2: MUTUAL AID AMONG ANIMALS (continued) Migrations of birds.-- Breeding associations. -- Autumn societies. -- Mammals: small number of unsociable species. -- Hunting associations of wolves, lions, etc. -- Societies of rodents; of ruminants; of monkeys. -- Mutual Aid in the struggle for life. -- Darwin's arguments to prove the struggle for life within the species. -- Natural checks to over-multiplication. -- Supposed extermination of intermediate links. -- Elimination of competition in Nature. As soon as spring comes back to the temperate zone, myriads and myriads of birds which are scattered over the warmer regions of the South come together in numberless bands, and, full of vigor and joy, hasten northwards to rear their offspring. Each of our hedges, each grove, each ocean cliff, and each of the lakes and ponds with which Northern America, Northern...