Anatomical Differences – Carnivores
A carnivore is an animal or plant that eats the flesh of animals. Most, but not all, carnivorous animals are members of the Carnivora order; but, not all members of the Carnivora order are carnivorous.
A carnivore is simply any species that eats meat, and this can range from carnivorous plants and insects to what we typically think of when we hear the word carnivore, like tigers or wolves. There are three different categories of carnivores based on the level of meat consumption: hyper-carnivores, meso-carnivores and hypo-carnivores.
Anatomical features common to carnivores confirm their adaptation for a primary meat-based diet.
- Short, Simple and Acidic Digestive Tracts. Protein and fat from animal sources are quickly and easily digested, hence the short digestive systems;
- Hydrochloric acid secretion is exceptional. To facilitate protein breakdown and kill the bacteria found in decaying meats, carnivores are able to keep their gastric pH around 1 to 2;
- Sharp Teeth, designed for slicing meat, not grinding plants. Carnivores have elongated teeth designed for tearing and killing prey, their molars are triangular (and not flat) with jagged edges that function like serrated-edged blades that give a smooth cutting motion;
- Jaws move vertically, unlike herbivores that grind their food side to side chewing, the jaws of carnivores operate vertically to provide a smooth cutting motion, and open widely to swallow large chunks of meat;
- No amylase in saliva. Amylase in saliva is something omnivorous and herbivorous animals possess, but not carnivorous. As amylase is not present in saliva, the burden is entirely on the pancreas to produce the amylase need to digest carbohydrates.
Carnivores generally have large eyes, placed so that the eyes look forward and the areas of vision of the two eyes overlap. This means that they have binocular vision and they see objects with both eyes at the same time. This provides them with good depth perception. On the other hand, herbivores have eyes that face to the side, giving them monocular vision; an object is seen with only one eye at a time. While herbivores lack depth perception, they can watch for approaching predators in all directions. Some speedy herbivores, like deer, have eyes that overlap slightly. This provides limited depth perception so they don’t run into trees as they flee from danger. Omnivores generally have eyes facing mainly to the front. This gives them partly binocular vision and helps them in their search for a wide variety of food.
While some carnivores eat only meat, other carnivores also supplement their diets with vegetation on occasion. For example, most bears are omnivores, which means they eat both plants and meat.
Hyper-carnivores creatures are considered obligate carnivores because they cannot properly digest vegetation and have a diet that consists of at least 70 percent meat, according to National Geographic. The cat family, including lions, tigers and small cats like our fur kids, for example, are obligate carnivores, as are snakes, lizards and most amphibians.
Many hyper-carnivores, including some members of the Carnivora order, have heavy skulls with strong facial musculature to aid in holding prey, cutting flesh or grinding bones. Many also have a special fourth upper molar and first lower molar. They close together in a shearing action, like scissors, which allows the carnivore to slice meat from their prey. These two teeth together are called the carnassial teeth.
Meso-carnivores are animals that depend on meat for at least 50 percent of their diet. Along with meat, these animals will also eat fruits, vegetables and fungi. Meso-carnivores are typically small to mid-size species and often live close to human populations. Raccoons, foxes and coyotes are “accepted” examples of meso-carnivores. Perhaps the species “dog” should have been labeled a “meso-carnivore”?
Hypo-carnivores are carnivores that eat the least amount of meat — less than 30 percent of their diet, according to National Geographic. These animals, which can also be considered omnivores, eat fish, berries, nuts and roots, as well as meat.
Though carnivores come in many shapes and sizes, they do share a few similarities. Most carnivores have relatively large brains and high levels of intelligence. They also have less complicated digestive systems than herbivores. As discussed, many herbivores have multiple stomachs, while carnivores only have one, according to Encyclopedia Britannica.
For the purposes of our hypothesis, our species “dog” anatomy and physiology correctly tells the story. Their teeth, jaw structure, large stomach, relatively short and simple small intestine and a very short large intestine identifies them as a carnivore.
Though all carnivores eat meat at some level, the frequency of their feeding can vary. Warm-blooded carnivores tend to burn a lot of calories (energy). Because of this, they have to hunt and eat often to keep to keep up their energy levels. Cold-blooded carnivores, on the other hand, use fewer calories and can rest days or even months between meals.
Carnivores sit at the third trophic level in the food web, along with omnivores. Carnivores eat other carnivores, as well as herbivores and omnivores, depending on their species, according to National Geographic.
As the top tier of the food web, carnivores keep the populations of other animals in check. If a carnivore population is wiped out by disease, natural disasters, human intervention or other factors, an area can experience an overpopulation of other creatures lower in the food chain.
Many carnivores are scavengers, creatures that eat the meat of dead animals, or carrion. Unlike other types of carnivores, scavengers usually do not hunt the animals they eat. Some, such as vultures, consume animals that have died from natural causes. Others, such as hyenas, will snatch meat hunted by other carnivores. Many insects, such as flies and beetles, are scavengers.