Most Populated Animals In The World

1. India's Tiger Population Rises, Madhya Pradesh Has Most Big Cats
2. The Threat To The World's Largest Wild Animals Is Much Greater Than We Thought
   1. Of The World's Most Endangered Animals
3. Pangolin Facts And Information
   1. World's Most Dangerous Animals
4. Along With Humans, Who Else Is In The 7 Billion Club?
5. The Big Wildlife Census: How Many Animals Are In The World?
6. The World's 10 Favorite & Most Popular Animals In 2024
7. Animal Populations Experience Average Decline Of Almost 70% Since 1970, Report Reveals
8. This Heartbreaking Map Shows Where The Most Endangered Animals In The World Are

Originally published on April 5, 2023, this article has been updated on October 7, 2023 to reflect the latest research and statistics. Our editorial team has ensured you’re viewing the most current data on this topic. Need help or have a question? Email us.

I love nature. There is something amazing about being outside and seeing how many different animals, insects, birds, fish, and more are actually present in our world.

Sadly, some existing species are also annihilated from the animal kingdom by evolutionary pressures and the human impact on the earth. But back to my question: Just how many animals are in the world?

India's Tiger Population Rises, Madhya Pradesh Has Most Big Cats

There are many diverse opinions about just how many animals are in the world, especially if the idea of “animals” includes fish, insects, birds, and more.

The Estimated Number of Animal Species in the World Is 2.16 Million, From the Total Species Population of 8.7 Million (IUCN, Plos.org)

Of the 8.7 million species that exist on earth, we would probably consider 2.16 million species to be animals; however, the other 0.3 million species are made up of living animals, too—such as amphibians, corals, and crustaceans.

The Most Dangerous Animals In The World

Of the animal species that have a spine (also known as vertebrates), there are 62, 000 species that have been identified as having existed or currently existing. (source)

The largest chunk of the 2.16 million species that exist across our planet belongs to the invertebrates, or species that have no spinal column.

In fact, 97% of all animals are invertebrates—so think twice before you smash that spider crawling across your desk; they outnumber you and me! (source)

The Threat To The World's Largest Wild Animals Is Much Greater Than We Thought

I’m not a fan of bugs. I mean, I love all animals, but I tend to avoid the “creepy crawlies.” Yet, a massive 140, 000 invertebrate species exist in the US alone. (source)

Sadly, many people don’t appreciate the “bug” part of our biodiversity, so they may choose to exterminate insects and other critters instead of first finding out how helpful or harmful that invertebrate is. Because of this, over 200 species of invertebrates in the US have become endangered.

Imagine bugs to a total of 10, 000, 000, 000, 000, 000, 000. Even the zeros make my skin crawl! But hey, live and let live (after all, the bugs outnumber us by quintillions).

Of The World's Most Endangered Animals

Back to the warm and loving mammals, there are more than 6, 400 species of mammals that have been officially identified on Earth. If you can’t remember your high school biology, mammals are animals that nurse their young, such as cows, pigs, and human beings (we’re animals, too). (source)

If you have jumped on the reptile bandwagon and have a beardie looking at you from its vivarium, you probably wonder how many species of reptiles have been identified on Earth. The answer is an impressive 10, 000 species and 2, 700 subspecies (source)

Perhaps you have a great big bullfrog glaring at you through the sides of your terrarium? Well, satisfy your curiosity, as there are 8, 698 species of amphibians.

Most Populous Animals On Earth

The US has an ARMI approach to amphibians, that is, the Amphibian Research and Monitoring Initiative (ARMI), to track just what has been happening in the amphibian kingdoms. (source)

We do have a responsibility to keep an eye on all living animals, including slippery amphibians, as 300 of the 8, 698 species exist in the US.

Not forgetting your goldfish in its nice tank, the answer to how many fishes are in the world’s waterways and oceans is estimated at 3.5 trillion. (source)

How Many Animals Are Killed For Food Every Day?

While that may seem like a lot of fish, we are fast depleting the world’s fish population as fish is a major source of protein for most of the world’s humans.

I can’t leave out my beloved chickens in this headcount of animal species, and there are 11, 000 species of living birds in the world.

I say living birds because so many bird species have been driven to extinction by human activities like deforestation and because of the use of agricultural poisons and herbicides.

The Rarest & Most Endangered Animals In The World

Okay, so I now had a fair indication of how many animals are on Earth, but I wanted to know just how many species of animals are living on this crazy rock spinning around the sun with me.

I’m also not alone in wanting to know this, and the International Union for Conservation of Nature’s (IUCN) Red List for animals nearing extinction keeps track of all the animal species on earth and releases updated counts each year.

According to the IUCN Red List, there are 1.053 million species of insects on earth. Of this number of species, only 1.2% of all insect species recorded have been evaluated for their status as critical or endangered for the Red List.(source)

Pangolin Facts And Information

The vast diversity of our planet’s wildlife is exemplified by the astonishing numbers of described bird and reptile species. According to the IUCN Red List, a staggering 11, 188 bird species grace our skies, while 11, 733 reptile species slither, bask, and swim across various terrains.

My fellow mammals and I make up 6, 596 species, of which 91% have been evaluated for the Red List according to the IUCN Red List.

Yeah, you read that statistic correctly. A staggering thought: Most of all land species (86%) and even more (91%) of sea species haven’t even been discovered yet, according to a study published by PLOS Biology.

World's Most Dangerous Animals

That means that we only know 14% of all land animal species and a mere 9% of all species that live in the oceans of our planet.

There are many different types of animals in the world, and these species can be divided into categories of mammals, reptiles, amphibians, fish, invertebrates, and birds.

Mammals are any animal that gives live birth to their offspring, such as humans, cows, pigs, antelope, dolphins, and more. Animals that birth their young also suckle their offspring, which is why they are called mammals (as in having mammary glands).

Along With Humans, Who Else Is In The 7 Billion Club?

Since mammals are also vertebrates—they have a spine as part of their bone structure. But, interestingly, not all vertebrates are mammals as a vertebrate, like a crocodile, is a reptile, not a mammal, since it lays eggs (even though it may look after those young, it doesn’t nurse them).

Mammals are also warm-blooded and usually have fur, though dolphins and whales are the oddballs here as they are both cold-blooded and have skin and not fur.

Reptiles are vertebrates, and they have a skeleton, including a spinal column. Yip, even a slithery snake has a spine, making it a vertebrate.

The Big Wildlife Census: How Many Animals Are In The World?

A reptile is coldblooded, meaning it has to gather heat from its environment (which is why you see lizards sunning themselves in the morning), and reptiles usually don’t give birth to live offspring but lay eggs instead.

Some snakes, like boas and pythons, may give birth to live offspring, though these offspring are immediately independent and don’t require any nursing or care from their parents.

When you hold a reptile, it’s not a warm body you can cuddle, though reptiles are intelligent and can make great pets. Reptiles have hardened skin or scales like a snake. Some reptiles, like turtles, also have a shell to protect their bodies.

The World's 10 Favorite & Most Popular Animals In 2024

All reptiles are vertebrates, but, as I mentioned above, some vertebrates are mammals, not reptiles, while other vertebrates may be birds or fish.

When I say amphibian, most people will immediately think: Frog. And you’d be correct, but frogs aren’t the only species of amphibians known to us.

Amphibians are also vertebrates, and while they may seem fish-like, amphibians have a unique skeletal structure that includes four limbs. Amphibians are also native to aquatic environments, meaning they need water to survive, even though they usually breathe air too.

Animal Populations Experience Average Decline Of Almost 70% Since 1970, Report Reveals

There are several species of amphibians that live in trees, while others live in pools, rivers, lakes, or even on land. Usually, amphibians lay eggs and have little to no parental care for their young.

When the offspring have hatched, they may go through transformative stages to reach maturity, such as tadpoles that become full-grown frogs after starting in a fish-like shape, then growing a set of forelimbs followed by the back limbs until they resemble their parents.

I like eating fish as much as the next person, but I hate the bones. They have bones because, you guessed it, fish are vertebrates too. Fish have scales, and they are coldblooded, but they may or may not give live birth to their offspring.

Astounding: The German Animal World

Some fish may raise their young, such as the seahorse, while others simply spawn eggs like salmon and then move on with life.

Fish have evolved over centuries, and since they have the largest habitats on earth—our lakes, rivers, and oceans—there are a huge number of species of fish.

Keep in mind that the number of fish species is more than 34, 000 species, as only 91% of all ocean life has been cataloged or identified.

This Heartbreaking Map Shows Where The Most Endangered Animals In The World Are

While vertebrates have bones, invertebrates have no bones or no spinal column. Invertebrates are usually cold-blooded animals with soft bodies that are not rigid unless they have an outer shell or exoskeleton.

There are more invertebrates than vertebrate species, and there is also a much greater diversity within the classified species. From tiny micro-organisms that are invertebrates to large animals like the