Critically Endangered Species (original) (raw)

Updated: February 3, 2021

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Critically endangered species are at a very high risk of becoming extinct in the wild or extinct. For an animal to be added to the category, it must meet any of the following criteria regarding population or habitat decline:

Rapid Population Reduction

A taxon’s population size is reduced by 90 percent or more over 10 years or three generations, whichever is longer, and the reduction causes are understood, reversible, and have stopped. For example, let’s pretend there’s a bird species that traditionally had a population of 2000. Over 10 years, it drops to 200 because a logging company demolished its habitat. If laws are put in place that bar the logging company from continuing to fell trees in the habitat, then the IUCN will list it as “critically endangered” because the reason for the decline is understood and ceased.
A taxon’s population size is reduced by 80 percent or more over 10 years or three generations, whichever is longer, but the reduction cause may not be understood or reversible. For example, let’s say there’s a bird species that traditionally had a population size of 2000. Over 10 years, it drops to 400. However, scientists can’t figure out why they’re dying off. In this case, the IUCN would list it as “critically endangered” because the decimation is evident, but scientists can’t figure out why.
A taxon’s population size is reduced by 80 percent or more over 10 years or three generations, whichever is longer, and the animal is also battling habitat shrinkage or another threat.

Geographic Reduction

The area where a species can live is reduced to 100 square kilometers or less, or the area that the species currently and actually occupies is reduced to 10 square kilometers, and at least two of the following criteria are also met:

The population is known to exist in only one location.
Scientists observe or predict that the habitat will continue to shrink or be degraded, and there’s also a decline in subpopulations or the number of reproducing adults.
Scientists observe extreme fluctuations in the number of locations, subpopulations, or the number of reproducing adults.

Dangerously Low Number of Adults

A taxon’s population only has 250 or fewer adults left, and a 25 percent decline is anticipated within three years or one generation, whichever is longer. If none of the taxon’s subpopulations contain more than 50 adults, or 90 percent of the species’ adults live in one subpopulation, it will qualify as critically endangered.
Scientists observe extreme fluctuations in the number of mature adults in a given population.

Dangerously Low Overall Population Size

Only 50 or fewer individuals of a taxon remain.

Expected Rapid Decline

Research and studies indicate that there’s a 50 percent or greater chance that the taxon will be extinct in the wild within 10 years or three generations, whichever is longer.

How many species are currently critically endangered?

In the latest iteration of the list, 3,947 taxons — aka scientifically accepted units of species — are classified in the critically endangered category.

Critically Endangered Species

Addax

The hooves of the addax are splayed and have flat, springy soles, one of the adaptations that help it walk over sand.

African Elephant

Both male and female African elephants have tusks. In Asian elephants, only the males have tusks.

Agouti

The agouti is one of the only animals that can crack open Brazil nut pods!

Amur Leopard

The Amur leopard may be the rarest big cat on Earth!

Angelshark

The angelshark’s range has contracted by more than 80% in the past century.

Balkan Lynx

The Balkan lynx communicates mostly with its ears

Bass

Prized by sport fishers for their size and strength

Blobfish

One of the ugliest creatures in existence!

Bongo

Long and heavy spiralled horns!

Campine Chicken

Campine chickens were exported from Belgium by Julius Caesar!

Canadian Horse

Canadian horses are believed to generate more power per pound of body weight than any other horse breed in the world.

Chinese Alligator

Unlike other alligators, the Chinese alligator is armored all over, even on its belly.

Coelacanth

The coelacanth first evolved almost 400 million years ago.

Crocodylomorph

Crocodylomorphs include extinct ancient species as well as 26 living species today.

Deer Mouse

Roughly 60 different species of deer mice range from Canada to Central America!

Desert Wolf

These tiny wolves prefer to cohabitate in pairs or groups of three (generally two males and a female).

Douc

When these monkeys want to mate, they wiggle their eyebrows.

Egyptian Tortoise

The Egyptian tortoise is one of the smallest tortoise species in the world.

Finch

Finches have strong, conical bills that help them break open tough seeds that many other birds cannot.

Freshwater Eel

Freshwater eels are actually catadromous, meaning they migrate to saltwater to spawn

Gazelle

Named for the Arabic word for love poems

Gharial

Males can blow bubbles using the bump on their snout!

Golden Mole

The golden mole is so named because of its iridescent coat, which gives it a shining, rainbow-like effect.

Great Hammerhead Shark

Great hammerhead sharks have a 360-degree view because their eyes are situated on the ends of their mallet-like heads.

Grouper

Many grouper can change their sex, and it is always from female to male.

Hornbill

The bird has a massive horn on its bill!

Houdan Chicken

The Houdan chicken has a round, fluffy crest and five toes on each foot!

Kouprey

The kouprey is one of the rarest mammals in the world

Lineback Cattle

The lineback cattle has been an integral part of rural New England society for more than 200 years!

Loris

Like all lorises, slow loris has a cute wide-eyed look, but it also has a venomous sting that can rot human flesh.

Marsican Brown Bear

They do not fall completely asleep during hibernation but wake up from time to time during the winter to walk around.

Myna Bird

Many people believe the hill myna bird is better at mimicking humans than a parrot!

Onagadori Chicken

The Onagadori, the chicken with the world's longest tail, was declared a Natural Monument of Japan in 1952.

Orinoco Crocodile

Orinoco crocodiles are the largest predators in South America; they're also going extinct!

Red-Headed Vulture

Not exclusively carrion eaters, these birds are also opportunistic hunters

Red Wolf

There are only 17-19 in the wild!

Saiga

Large noses help filter out dust

Sandpiper

Some sandpipers can migrate more than 8,000 miles without stopping!

Saola

Only known to science since 1992!

Sawfish

Sawfish teeth keep growing as the fish gets older

Scrotum Frog

The frog's ears are underdeveloped, and if it hears it probably does so through its lungs.

Spider Monkey

Belongs to the only family of primates in the world with full prehensile tails!

Sturgeon

Large species can swallow whole salmon

Sultan Chicken

Sultan chickens were bred for royalty and have more unique and distinctive features than any other breed!

Swallow

swallows have aerodynamic bodies for hunting in flight

Tamarin

These tiny yet intelligent monkeys often give birth to fraternal twins.

Tarantula

More than 1000 species of tarantulas have been identified all around the world!

Vaquita

Smallest cetacean in the ocean

Viper

Vipers are one of the most widespread groups of snakes and inhabit most

Yokohama Chicken

Yokohama chickens have snow white feathers with tails reaching up to 4 feet in length.

List of Critically Endangered Species

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A-Z Animals Staff

AZ Animals is a growing team of animals experts, researchers, farmers, conservationists, writers, editors, and -- of course -- pet owners who have come together to help you better understand the animal kingdom and how we interact.

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