Discover 9 Animals That Survive By Eating Meat Only

If you know much about animals, whether wild animals or domestic, you’ve likely heard of the three categories of animals based on their diets. You have herbivores that survive by eating plants. Then, there are omnivores, which eat a healthy mix of both animals and plants. Finally, you have carnivores, which are animals that survive by eating meat.

Or so it was thought. Now, scientists are starting to realize that most animals are some level of omnivore, even if they aren’t classified as such. Deer, for example, will eat mostly plants. Those plants make up a good portion of their diet. However, they will also, on occasion, eat meat and insects.

Wolves are on the opposite end of the spectrum. They are carnivores that get most of their food from meat. However, if they need a little more food, they’ve been known to eat berries and other fruits and vegetables on occasion.

But there are still some animals that are entirely carnivores. They eat almost nothing besides meat or animal products. Some aren’t able to digest plants at all, while others have adjusted to fit a niche that involves picking off prey species.

To learn more about these animals that survive by eating meat, and how they work, you’ll want to keep reading.

What Are Obligate Carnivores?

There are three main types of carnivores. These include thousands of animal species and even some plant species. Every one of these animals and plants falls into one of three groups.

Hypocarnivores

The first is hypocarnivores. These are animals still classified as carnivores, though omnivore is the more common term. They only need 30 percent of their diet to come from meat, on average. Animals classified as hypocarnivores, in addition to eating meat, eat berries, nuts, leaves, and roots.

This isn’t done to supplement their diet, but because they need plant nutrition just as much as they need nutrition from animal meats. Hypocarnivores often have large molars and somewhat small carnassial teeth.

Animals like grizzly bears, black bears, and humans are all examples of hypocarnivores because most of their diet comes from plants, but about 30 percent needs to come from meat or meat-based alternatives. Though you might expect bears to be at least omnivores, they don’t eat enough meat on average to be considered more than hypocarnivores

Mesocarnivores

Mesocarnivores get about half of their nutrients from meat, on average. The eating of plant and fungus materials is done to supplement their diet, rather than a strictly necessary component. They are often slightly smaller animals and tend to thrive around humans.

Some examples of mesocarnivores include foxes, skunks, raccoons, weasels, and coyotes. These animals adapt well to human environments because they aren’t picky at all, and will eat meats, fruits, vegetables, or human trash. Urban environments allow them to access a wide range of food easily.

Hypercarnivores

The last group are hypocarnivores. This is the category also often known as obligate carnivores. These are animals that have to eat meat. They don’t technically only eat meat, but 70 percent of their diet comes from meat. Even the other 30 percent is primarily animal products like dairy or eggs.

Not only does a huge part of their diet come from meat, but they need animal proteins to survive. This is why this group is full of animals that survive by eating meat. They do, out of necessity on occasion, eat plants. However, their bodies are not adjusted to properly digest these foods.

These animals often have strong facial muscles, especially around the jaw, and sharp teeth made for cutting flesh or grinding bones.

Unique Features of Obligate Carnivores

Obligate carnivores are called such because they must have meat. They need the nutrients only provided by other animals for their survival. Because of this, they have adapted to make their lives and the digestion process easier.

The most noticeable are their teeth and claws. Most carnivores, especially obligate carnivores, will mainly have rows of sharp teeth, and not that many teeth made for grinding and chewing. This is because the main purpose of these teeth is to rip and tear apart flesh.

A lot of carnivores don’t chew. Instead, they rip off chunks of meat and swallow them whole. Because of this, they don’t need to develop teeth for grinding. Generally, their jaws must also be powerful. They need to have a good enough grip that they’re able to clench onto prey to rip off flesh, or crack open the shells of some animals. If the animal does have claws, which not all obligate carnivores do, they will also be sharp, and long enough to catch prey.

Most carnivores are comparatively strong as well. They need to be able to take down their prey, whether that be a zebra or some insects. This usually means that in addition to being strong, carnivores need to be fast and have good reflexes.

A more subtle characteristic of carnivores is their digestive system. Plants have nutrients that are hard to break down and extract. Because of this, animals that eat a lot of plants need specialized and complex digestive systems. Cows, for example, have several stomachs to help them extract as much from plants as they can.

Carnivores, especially those that mainly survive on meat, on the other hand, don’t need as complex of a system. The animals that are specialized in eating meat, and have been so for a long time, often have very simple digestive systems with short intestinal tracts. They are simple but efficient.

Examples of Obligate Carnivores

Many different animals are classified as obligate carnivores. Some are more well-known than others. While they may not eat meat entirely, it does make up a vast majority of their diet, especially in ideal conditions.

1. Domestic Cats

Domestic cats are likely the most talked about obligate carnivores. This is because there is a push for a lot of people to try and turn their cats vegan, to match the owner’s lifestyle. While this can work for dogs if done properly, it’s nearly impossible with cats.

If you insist on feeding them mostly fruits, vegetables, and grains for their diet, you will find your cat to become sick and lethargic. Animals that survive on meat, like cats, aren’t able to make certain vitamins and amino acids like taurine and vitamin A. Though plant-based foods have these nutrients, cats don’t have a way to break down these foods enough to absorb the nutrients.

You may see your cat eat other foods, but it’s not for nutrition. Think about it as humans eating a candy bar. Does it offer any nutritional value? Not really. But it tastes good and makes us happy. That’s what other foods do for cats.

2. Tarsiers

Tarsiers are not only obligate carnivores, they are an animal that primarily eats insects to fill a niche in their environment. They are often known as obligate faunivores. Because they specialize in insects, they are the only primate that is considered to be an obligate carnivore. Most other primates are omnivores.

Though they prefer to have insects, that’s not all they eat. Tarsiers have also been known to prey on birds, lizards, bats, and snakes when the opportunity arises. Some subspecies of tarsiers primarily eat poisonous snakes.

They use their long fingers and toes to act as cages, grabbing animals and insects and trapping them before they can get away. Though they are small animals, they have wide mouths that let them eat foods larger than one might expect.

3. Crocodilians

It’s not just mammals that can be obligate carnivores. Crocodilian species are also animals that survive by eating meat. Most of their food comes from catching unaware animals that come by a river or lake to drink. All crocodilians are considered obligate carnivores, including crocodiles, alligators, caimans, and gharials.

It was thought for a long time that these animals only ate meat, and nothing else unless it was an accident. Then, in 2013, studies on the inside of crocodiles and alligators were done. It was found that they had a lot more fruit in their stomachs than suspected. Most of it was soft-bodied fruits. They also had some vegetables in their stomachs, on occasion.

Now, although crocodiles and related species are still considered obligate carnivores, they are also thought to eat fruits and vegetables for fun. Some scientists hypothesize that they are even important in some cases for seed dispersal.

4. Amphibians

Interestingly, most amphibians are obligate carnivores as they reach their adult phase. For example, axolotls eat mainly worms and insect larvae. However, if they have no other choice, they can eat algae for a few days to survive. Most frog species, once adults, are carnivores as well.

However, tadpoles are primarily herbivorous. As they transform from tadpoles into frogs, they become omnivores. Then, once they are full frogs, they move on to only eat animals, with insects and small rodents being the primary targets for most frogs. Some species are omnivorous, even when they reach the adult stage of their lifecycle, but obligate carnivores are more common.

There are also times when tadpoles can turn into omnivores at an early stage in their life, especially if small animals and insects are abundant in the water. Other amphibians, like salamanders, are also usually obligate carnivores.

5. Walruses

Unlike domestic cats, which can’t really handle fruits and vegetables at all, walruses do eat some foods besides animal meats. However, they have only been observed to eat plant-based foods in captivity, and never in the wild.

It’s unclear if this is because there aren’t that many fruits and vegetables in the wild near where walruses live, or if it’s just not their food of choice. However, it is clear that a walrus couldn’t survive on fruit and vegetables at all. They need plenty of fat to provide them with enough blubber to keep them warm in the water. They also have specialized adaptations that help them eat and locate meats, such as sharp teeth and sensitive whiskers.

Mostly, walruses eat shellfish and mollusks. When they are desperate, however, they will eat fish and even seals. Walruses eat quite a bit every day, up to six percent of their body. This equals up to 6,000 clams twice a day, every day.

6. Dolphins

Another mammal that calls the sea their home and is an obligate carnivore is the dolphin. Dolphins eat primarily fish, squid, krill, and other mollusks. Their habitat determines what animals they eat. No matter where they are found, though, dolphins are found to pass up on grasses and plants in the water in favor of fish and other aquatic animals.

Though they will gladly eat jellyfish, or fight with an octopus to get a meal, dolphins of every species and as a whole, tend to prefer fish. One dolphin will eat up to 40 pounds of food a day.

An interesting fact about dolphins is that they can’t chew. They have teeth, but they’re only to catch their prey. Chewing gives fish and other animals time to escape, even if injured. So by catching an animal and swallowing it whole, they reduce the chances of losing out on a meal they worked hard to catch.

7. Polar Bears

Most bears are omnivores, including the grizzly bear and the black bear commonly found throughout the United States. However, the polar bear is a carnivore. It’s the only obligate carnivore out of all bears, as its diet is entirely made of meat.

This is because they need to put on weight for hibernation. Other bears are offered a lot of choices of food, including berries, fish, and human trash. Polar bears live on the ice and have fewer choices. To get enough calories to survive through the harsh winter, they have to eat fatty animals.

Fatty seals, walruses, and whales (usually already dead) are the primary meals for polar bears. Some they catch on their own, while others they come across that are already dead and frozen. Their absolute favorite prey is ringed seals, but they will eat anything they can.

If given the chance, they might turn into omnivores. As they move closer and closer to civilizations and areas without as much snow, they’ve been found to eat trash like their omnivore cousins.

8. Big Cats

Big cats are the most common wild obligate carnivores. This is because they are the most obligate of all obligate carnivores. Cat species like jaguars and cheetahs have some of the shortest intestinal tracts of any animal. This is the reason why they do so well with meat, and not very well at all with plants.

Every feline out there is an obligate carnivore. This includes the more popular cat species like lions and tigers, but also the more unique animals like lynxes, ocelots, and servals.

Cats have adapted to be the most perfect of meat-eaters. They can break down any meat they eat to get as many nutrients as possible. They are so reliant on animals as their food source that to try and eat something else could make a big cat sick and malnourished.

9. Rainbow Trout

You might not expect fish that you can catch and eat to be on this list, but they are. One such fish is the rainbow trout. Found throughout the world, rainbow trout is said to taste nutty. It has a firm, but flaky texture.

Many people say that rainbow trout tastes better when wild-caught, due to their varied diet. So what do rainbow trout eat in the wild? Rainbow trout eat a ranged diet of insects, fish, eggs, worms, minnows, and even crustaceans. They primarily eat invertebrates like insects, but won’t hesitate to eat anything that swims by them.

Because most of their diet consists of other animals and animal products like eggs, rainbow trout are obligate carnivores. They have to eat meat of some kind to survive, though they aren’t necessarily picky when it comes to the type of meat.

Why Do These Animals Have to Eat Meat?

The main reason that obligate carnivores have to eat so much meat is because that’s what they adapted to. Their stomachs and digestive systems are uniquely adapted to eating meats. What they are not adapted for is eating hard-to-digest plants.

Sometimes, these plants just don’t have the nutrients that carnivores need. Others, even if they have the right nutrients, are unable to extract those nutrients because their digestive systems aren’t developed enough.

For most obligate carnivores, unless they are filling a certain niche, there is no specific kind of meat that works better. This means that, in a way, they are actually less picky than herbivores. There are no plants they will avoid, or can’t eat. Most animals are happy to take what they can get, as meat is meat.

Bigger predators will even eat insects and small animals, though they try not to do this unless there’s no other choice due to the sheer number they have to eat.

Obligate carnivores also get more calories in smaller meals. Most herbivores need to eat a majority of the day to reach their caloric needs. Carnivores, on the other hand, only eat a few times a week, if that much. By eating meat, they don’t have to spend as much time browsing and searching for food as a herbivore would to reach their calorie goal. A carnivore may also need a higher ratio of fat and protein to keep their systems moving as intended.

Meat-eaters also fill a niche. They are generally apex predators. If it wasn’t for these large and intimidating animals, prey species like deer, rabbits, and even bison would quickly reproduce to uncontrollable levels. This in turn would harm the plants in the area. Carnivores help control that population.

Summary of Animals That Are Obligate Carnivores

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