Endangered Species

An endangered species is a species in serious danger of going extinct: numbers have fallen so low, or threats are so severe, that the species may disappear in the near future without help. Around 1 million species are currently threatened with extinction, mostly because of human activity (habitat loss, climate change, pollution, hunting). Conservation work, when properly resourced, can and does bring species back from the brink. This page introduces what endangered means, which animals are most at risk, and what is being done.

  • Species at riskapprox. 1 millionIn coming decades
  • Tiger populationapprox. 4,500 in the wildDown from 100,000 a century ago
  • Black rhinosapprox. 6,500Down from 65,000 in the 1970s
  • Mountain gorillasapprox. 1,000Slowly recovering after years near zero
  • Northern white rhinos2 leftBoth female, can no longer breed naturally
  • Extinct in recent centuries900+ speciesIncluding dodo, passenger pigeon, thylacine

The IUCN Red List

The most authoritative ranking of how endangered different species are is the Red List, published and updated by the International Union for Conservation of Nature (IUCN). The Red List has nine categories:

  • Extinct: no living individuals known.
  • Extinct in the Wild: only survives in captivity.
  • Critically Endangered: extremely high risk of extinction.
  • Endangered: very high risk of extinction.
  • Vulnerable: high risk of extinction.
  • Near Threatened: likely to become threatened soon.
  • Least Concern: not currently at risk.
  • Data Deficient: not enough information to judge.
  • Not Evaluated: has not yet been assessed.

The Red List currently lists over 44,000 species in the threatened categories (Vulnerable, Endangered or Critically Endangered). The total list of species reviewed is over 160,000.

Famous endangered animals

Some of the world's most famous endangered species:

  • Tigers: down to around 4,500 in the wild. Threatened by habitat loss and poaching.
  • Black and white rhinos: hunted near extinction for their horns. Just 2 northern white rhinos left (both female).
  • Mountain gorillas: around 1,000 remaining in the mountains of central Africa.
  • Sumatran orangutans: under 14,000 left, hit hard by palm oil plantation expansion.
  • Vaquita: a tiny porpoise in Mexico's Gulf of California. Under 10 individuals left; almost certainly heading for extinction.
  • Snow leopards: around 4,000 to 7,000 left in central Asia's mountains.
  • African forest elephants: declined by over 86% in the last 30 years due to poaching for ivory.
  • Hawksbill sea turtles: hunted for their beautiful shells; now critically endangered.

What threatens species

Almost every endangered species is threatened by one or more of these human-caused problems.

  • Habitat loss: forests cleared for farms and cities, wetlands drained, coral reefs destroyed.
  • Climate change: rising temperatures shift habitats faster than many species can adapt.
  • Hunting and over-fishing: too much pressure from food, sport or trade in body parts (ivory, rhino horn).
  • Pollution: pesticides, plastic, oil spills, chemical runoff.
  • Invasive species: rats, cats and other species introduced to islands often eat the local wildlife to extinction.
  • Disease: amphibians worldwide are being decimated by a fungal disease called chytrid.

Some conservation success stories

The picture is not all bad. Many endangered species have been brought back from the edge of extinction thanks to careful conservation.

  • Bald eagle: down to 417 nesting pairs in the US in the 1960s. Now over 300,000. The pesticide DDT (which thinned their eggshells) was banned in 1972.
  • Giant panda: numbers grew from under 1,000 in the 1970s to nearly 2,000 today thanks to habitat protection in China. In 2016, downgraded from "Endangered" to "Vulnerable".
  • Humpback whale: hunted to near-extinction in the 20th century. Now recovering well thanks to bans on commercial whaling.
  • California condor: down to just 22 birds in 1987. Captive-breeding has brought numbers to over 500 today.
  • European bison: extinct in the wild in 1927. Brought back from zoo populations, now numbering over 6,000 wild bison.
  • Iberian lynx: was the world's most endangered cat with under 100 left in 2002. Now over 1,500 thanks to extensive conservation.
Fact The passenger pigeon used to be the most numerous bird on Earth. Flocks of over a billion birds would darken the skies of North America in the 1800s. By 1914, the last passenger pigeon (a female called Martha) died alone in the Cincinnati Zoo. Massive hunting (millions were shot or trapped each year for food) combined with deforestation brought the bird from a population of perhaps 5 billion to extinction in less than 100 years. It is one of the starkest reminders that no species is safe if humans choose to wipe it out.

What can be done

Conservation works through a mix of approaches.

  • Protected areas: national parks, nature reserves, marine protected areas where species are safe from hunting and habitat destruction.
  • Laws and treaties: international agreements like CITES regulate trade in endangered species and ban hunting of the most threatened.
  • Captive breeding: zoos and breeding programmes maintain populations of the most endangered species and reintroduce them to the wild.
  • Habitat restoration: replanting forests, restoring wetlands, removing invasive species.
  • Local community engagement: protection works best when local people benefit from looking after wildlife (eco-tourism, sustainable harvesting).
  • Anti-poaching enforcement: park rangers, sniffer dogs and tracking technology fight illegal hunting.
  • Climate action: cutting greenhouse gas emissions is increasingly essential to long-term conservation.
Did you know? Even small individual actions can help. Avoiding palm oil that comes from cleared rainforests, choosing certified sustainable seafood, supporting wildlife charities, not buying souvenirs made from endangered species, and creating wildlife-friendly habitats in your garden all add up. There are around 22 million private gardens in the UK, and together they cover an area bigger than all the country's nature reserves combined. What you do in your back garden matters.
Deeper dive: when is a species really "extinct"?

Declaring a species extinct is harder than it sounds. The official IUCN definition of extinct is: "when there is no reasonable doubt that the last individual has died". But how do you prove a negative? Maybe there are still a few survivors, hidden somewhere remote, just waiting to be rediscovered?

Several species have been declared extinct, only to turn up alive years or decades later. These are known as Lazarus species (after the man in the Bible who came back from the dead). Famous examples include:

  • Coelacanth: a deep-sea fish thought extinct for 66 million years, rediscovered alive off South Africa in 1938.
  • Takahe: a flightless bird from New Zealand, thought extinct since 1898, rediscovered in 1948 by a small team in remote mountains.
  • Black-footed ferret: thought extinct in 1979. A small population was found in Wyoming in 1981 after a dog brought a dead one home.
  • Lord Howe stick insect: thought extinct since 1920 after rats killed them all on Lord Howe Island. Rediscovered in 2001 on a single isolated rock stack 23 km away, 24 individuals surviving on a tiny patch of tea-tree shrubs.

Because of these surprises, the IUCN is now cautious about declaring species extinct. They usually wait several decades after the last confirmed sighting before making the call. There is also an in-between category, Critically Endangered (Possibly Extinct), for species that probably are extinct but where surveys have not yet been thorough enough to be sure. Some species have stayed in this limbo for many years.

The flip side is that genuine extinctions are often not noticed in real time. A species can become extinct without anyone realising it for years, especially small, obscure or poorly-studied creatures in remote habitats. So the actual number of recent extinctions is probably much higher than the official count, which makes the urgency of conservation that much greater.

For the big picture, see extinction and biodiversity. For specific animal groups, see mammals, birds and others.