"As human populations expand they necessarily appropriate ecological space required by other species. Human ‘competitive displacement’ of non-human organisms from their habitats and food sources is now the greatest contributing factor to . Consider that with only 0.01 % of total Earthly , H. sapiens’ expansion has eliminated 83 % of wild animal and 50 % of natural plant biomass. From a fraction of 1 % ten millennia ago, humans now constitute 36 %, and our domestic livestock another 60 %, of the planet’s much expanded mammalian biomass compared to only 4 % for all wild species combined. Similarly, domestic poultry now comprise 70 % of Earth’s remaining avian biomass. Meanwhile, commercial fishing depletes the oceans at the expense of rapidly declining marine mammals and birds. Seabirds are the most threatened bird group, with a 70 % community-level population decline between 1950 and 2010."