Human carnivory as a major driver of vertebrate extinction

Abstract

Although a considerable part of the anthropogenic impacts on other species has been caused by our habit of eating other animals, little attention has been given to understanding and quantifying how human carnivory threatens biodiversity globally. Herein we review the anthropogenic threats to 1000 species randomly selected among more than 46,000 vertebrate entries in the IUCN Red List database. We identified the following mechanisms by which human carnivory (i.e., our habit of feeding on other animals and related products) negatively affects the world's vertebrates: two mechanisms related to predation (predation and bycatch), two to competition (prey depletion and persecution), one to biohazards (any negative impacts caused by livestock or alien species whose introduction is linked to human carnivory), four to environmental changes (destructive harvesting practices, livestock, agriculture, and climate change), and a miscellaneous category for processes more indirectly connected with our high trophic position. Our conservative estimate, which does not include livestock impacts via agriculture and climate change, reveals that about one-quarter of the world's vertebrates are threatened by at least one mechanism related to human carnivory, and that this proportion is higher than that attributable to other leading causes of biodiversity decline including agriculture, forestry, infrastructure, pollution, invasive species, energy production and mining, fire regime and water systems modifications, and climate change. Our results suggest that human carnivory is the major driver of the current biodiversity crisis, and we hope our findings may contribute to raise awareness about this fundamental yet overlooked aspect of human ecology.

Keywords

• Biodiversity crisis
• Bycatch
• Human ecology
• Livestock
• Predation
• Trophic ecology