Species die out naturally, but it's happening faster than ever before.

Species today are vanishing at a rate a thousand times higher than before humans existed.
(National Geographic)

We are currently losing between 24 and 150 species a day.

These estimates are based on computer modeling by researchers.
(Yale School of Forestry & Environmental Studies)

Scientists are calling this "biological annihilation" the "sixth mass extinction."

The current mass extinction stands apart from previous ones because it's largely caused by humans.
(CBS News, citing PNAS research) 

Sec. 1

Which human activity is the #1 cause of species extinction?

Our dietary choices have a vast effect on the habitats of animals, plants and other organisms.”
— Prof. Ron Milo at the Weizmann Institute of Science

Farming animals for food is the number one cause of species extinction, as confirmed by researchers year after year. 

  • 2006 - World Conservation Union’s Red List of Threatened Species reports that most of the world’s threatened species are experiencing habitat loss as a result of livestock production.*

  • 2015 - Biodiversity conservation: The key is reducing meat consumption published in Science of the Total Environment finds: "Livestock production is the single largest driver of habitat loss." Researchers tell the media livestock production’s impact on land use is “likely the leading cause of modern species extinctions.”

  • 2017 - Appetite for Destruction summary report by WWF finds that excessive animal product consumption is responsible for 60% of all biodiversity loss, citing animal feed production as the largest culprit.

  • 2018 - The biomass distribution on Earth, published in PNAS, finds that animal agriculture has dramatically transformed the Earth's mammalian biomass into 60% "livestock," 36% humans, and just 4% wild. Birds are now 70% "livestock" and just 30% wild. The lead researcher told the media he is moving to a more plant-rich diet as a result of his findings. (The featured quote above is his.)

*This report doesn't appear to be online, but the above is mentioned as early as 2006 in the UN FAO report "Livestock's Long Shadow."


Earth's Current Biomass: Mammals

Earth's Current Biomass: Birds

Hover on pie chart segments for percentages. Data source: The biomass distribution on Earth / Yinon M. Bar-On, Rob Phillips & Ron Milo / PNAS / May 21, 2018

The consumption of animal-sourced food products by humans is one of the most powerful negative forces affecting the conservation of terrestrial ecosystems and biological diversity.
— "Biodiversity conservation: The key is reducing meat consumption" in Science of The Total Environment Volume 536, 1 December 2015
Producing livestock, including cattle, goats and sheep, for human consumption is the single largest driver of habitat loss and deforestation worldwide.
— Evelyn Perez, Florida International University, summarizing published research study "Biodiversity conservation: The key is reducing meat consumption"

Sec. 2

How exactly does animal agriculture kill wild animals & cause species to go extinct?

The introduction of so-called livestock to areas where there were none previously (often starting with colonization) causes a cascade of ongoing impacts on native species.

  • Land conversion - Converting land for animal farming (both grazing and/or growing their feed) depletes the ranks of numerous native wild plant and animal species who were there first.

  • Fences - The countless fences that keep "livestock" under human confinement and control dramatically interfere with and harm wildlife, such as sage grouse.

  • Disease spreading - The introduction of "livestock" brings new animal diseases that devastate some native animals.

  • Ongoing wildlife "culling" - Purposeful efforts (including by government agencies) are made to eliminate wild animals that prey on "livestock" and/or compete with them for resources. Just a few examples include:

    • Wild horses: May compete with "livestock" for resources and so are torn from their lands and families by the Bureau of Land Management, with many slaughtered.

    • Bison: Ranchers perceived bison as a high-level competitor with cattle, even despite evidence to the contrary, so they are "controlled" with "sport hunting."

    • Buffalo: In the Maasai Mara National Reserve, the buffalo population was nearly 13,000 in 1992, but has since sharply decreased. "During the drought, they were pushed out of feeding areas by [farmed] sheep and other cattle, and the buffalo population crashed by 76% in one year. They've never recovered."

    • Elk: Ranchers claim that native tule elk, nearly wiped out in California before being reintroduced, should be removed as an “invasive” species” to leave grasslands for cattle ranching and dairy operations.

    • Grey wolves: May prey on "livestock" – especially when their regular prey have been killed by ranchers/targeted by hunters – but ironically, killing them may cause even more unplanned "livestock" deaths.

    • Kangaroos: In Australia, the vast majority are culled "as part of a commercial meat-hunting industry tied to the entrenched notion that kangaroos are pests that compete with livestock for grass."

    • Cougars: As of 2018 cougars were officially declared extinct in Eastern U.S. and removed from endangered species list, as reported by the Yale School of Forestry & Environmental Studies who name "livestock" farming as a cause. These animals are targeted by farmer and ranchers throughout North America.

    • Badgers: An unscientific massive ongoing badger cull in the UK is intended to curb tuberculosis in cattle to "protect the future of our dairy and beef industries."

    • Warthogs, antelope, zebra & more: The populations of wild animals in Kenya fell by 68% between 1977 and 2016. The affected species included warthogs, many species of antelope and the rare Grevy's zebra. During the same period, farmed sheep numbers increased by 76.3%.

      Other casualties of the natural world include:

    • Insects: "Intensively farmed wheat and cornfields [used mostly as animal feed] support virtually no insect life, and this means that as intensive agriculture spreads there are fewer and fewer islands of natural habitat left to support them."

    • Plants: "There are dozens of local native plants that are jeopardized by cattle grazing and at least 21 of our endangered and threatened wildlife species in the Bay Area are harmed by cattle grazing."

    • Wildfires: Heavy livestock grazing suppresses protective soil crusts and native grasses like sagebrush while simultaneously spreading a highly flammable invasive weed called cheatgrass, setting the stage for more frequent and intense wildfires.

Despite being the largest cause of species extinctions, both grazing/pasturing animals & feed production are massively subsidized. Plus, "cowboys" yield cultural power as well as political influence through lobbyists. 

(See Overview for more on both topics.)

  • Ranching/grazing

    • Grazing takes up 26% of Earth’s ice-free terrestrial surface (UN FAO).

    • Ranching is promoted, protected and subsidized on 270 million acres of US public lands in 11 western states, imperiling more than 175 threatened or endangered species. (Center for Biological Diversity)

  • Feed production

    • Growing feed crops takes up one third of global arable land. (UN FAO)

    • The recent report "Appetite for Destruction" found that growing animal feed is the largest cause of global biodiversity loss. (WWF)

From a conservation viewpoint, cattle grazing is simply incompatible with maintaining and restoring wildlife, native plants and natural resources.
— Karen Klitz and Jeff Miller for Bay Nature

Use of agricultural land worldwide

Livestock is the world's largest user of land resources, with grazing land and cropland dedicated to the production of feed representing almost 80% of all agricultural land. Source: UN FAO, Animal Production, www.fao.org/animal-production/en/
Grazing livestock are a fully automated system for ecological destruction: you need only release them on to the land and they do the rest, browsing out tree seedlings, simplifying complex ecosystems. Their keepers augment this assault by slaughtering large predators... The damage caused is out of all proportion to the meat produced.
— George Monboit (Guardian journalist & UN Global 500 Award winner for outstanding environmental achievement)
In a world where more and more people adopt a Western diet – one
that’s high in meat, dairy and processed food – producing crops to feed
our livestock is putting an enormous strain on our natural resources and
is a driving force behind wide-scale biodiversity loss.
— WWF Summary Report "Appetite for Destruction," November 2017

Note: We debunk the idea that hunting is an effective means of conservation here.

Sec. 3

So what really conserves species?

Setting aside and re-wilding more land is logically the most effective way to truly stop the sixth mass extinction.

Esteemed biologist and National Geographic Hubbard Award winner E.O. Wilson, has outlined a bold new plan to set aside half the planet for conservation, which he says would conserve 80 to 90 percent of all species on Earth. He says this can only happen "if people eat significantly less meat and livestock products, a trend that is currently going in the opposite direction globally."

Remember, animal agriculture currently occupies nearly half the global surface area (ILRI). Setting aside and re-wilding land cannot be done on a large scale without a collective shift to plant-based diets, due to their much lower land use and material cost.

“Setting land aside in the public domain in perpetuity is probably the most substantive thing we do for wildlife conservation.”
— Thomas Serfass, a professor at Frostburg State University in Maryland and chairman of its department of biology and natural resources
Abandonment of meat-eating would undoubtedly free vast areas of ecological land” for “forestry and wildlife conservation.
— The Ecologist chairman Edward Goldsmith, a meat-eater himself, in a 1976 debate (detailed in the book “Meat: A Benign Extravagance")
...we can accomplish magnitudes of recovery more if conservation biologists introduce native species in tandem with the end of animal agriculture... Livestock were never needed as replacements to benefit ecosystems.
— Will Anderson, environmental activist and author who co-founded the Maine Animal Coalition and Greenpeace Alaska

Further reading:

How Eating Meat Hurts Wildlife and the Planet (Center for Biological Diversity)
Appetite for Destruction (WWF)
Biodiversity conservation: The key is reducing meat consumption (Science of the Total Environment)
Extinction and Endangered Species (Encyclopedia.com)
The Ecological Costs of Public Lands Ranching (Western Watersheds Project)
Waste of the West: Public Lands Ranching (Lynn Jacobs)
Welfare Ranching: The Subsidized Destruction of the American West (Public Lands Ranching)
Save the Animals, Save the Earth
Extreme Wildlife Declines and Concurrent Increase in Livestock Numbers in Kenya: What Are the Causes? (PLOS One)
If you want to save the tiger, first save the cow – this is how veganism protects the jewels of our natural world (The Independent)


Scientists are predicting the "sixth mass extinction" and animal agriculture is its number one cause. "Livestock" farming has ongoing impacts on native plant and animal species due to land conversation for grazing and growing feed, diseases, and the routine culling of competing/threatening prey and predator animals. Hunting is not a legitamate conservation solution. The most effective way to actually conserve species is to set aside and re-wild far more land than we currently are, which requires a shift to plant-based diets.