Predators are wild animals that hunt, or prey on, other animals. All animals need food to live. Predator animals need the flesh of the animals that they kill to survive. Weasels, hawks, wolves, mountain lions, and grizzly bears are all predators. Predators are carnivores, which means their diet consists of meat. Some predators, such as coyotes and bears, are also scavengers, meaning they will eat the carcasses of animals that they didn't hunt themselves.
Opposite of predator, you have prey — the animals predators hunt and eat. Prey animals can be anything from the smallest insect to a 1400 pound bull moose. Some prey animals are herbivores, meaning they eat plants. Other prey species are omnivores, which means they will eat plants or animals.
Most times, the word predator brings to mind an image of snarling teeth and slashing claws. While many predators fit this image, many others do not. Predators come in many sizes and shapes. They can be as tiny as a bug or as large as a polar bear. What does a ladybug eat? You're right, other animals! What about that beautiful American robin that we welcome spring with? Yes, another predator! Are you getting the idea? Predators are animals that eat other animals. They're not bad guys. They're just creatures trying to feed themselves; they get hungry just like you and me. “Making a living” to them is finding enough food to eat. They don't have the option of going to the grocery store or the drive-in.
The Role of Predators
Predators are part of a food chain, the process of passing energy from one organism to the next. Plants are the first link in the food chain; they use the sun's energy to make food. Plants are called the producers.
Plant eaters, also called herbivores, enter the picture next. Predators such as birds and foxes join the food chain by eating the plant eaters and are known as primary consumers. These predators may become food for the next animal up the chain.
Predators that eat primary consumers are known as secondary consumers, which are also eaten by tertiary consumers or quaternary consumers. All of these are just layers of animals that eat from the lower layers. Finally you have your apex predator. This is the predator at the top of the food chain.
Most natural communities have several food chains that interconnect. This is called a food web. When a food web is drawn, it looks like a pyramid with the apex predator at the top and the plants eaters at the bottom. Plant eaters are the most abundant part of the web.
A food chain or a food web allows a small amount of the sun's energy to be passed along through each animal. When an animal dies, it decomposes, or breaks down, and provides the soil with nutrients that help plants to transform the sun's energy into food once again.
Balance of Nature
The relationship between predators and prey is often described as the balance of nature. A natural ecosystem does have a degree of balance — the number of plants and animals in an ecosystem tends to remain within a certain limit, which is not too great or not too small.
Predators, however, are not the only factor that affects a population. A variety of things cause the abundance of a species, including predators, food availability, the competition with other species, disease, and even the weather.
It is said that the predators in a particular area control the populations of prey species. In this way, the prey species won't overpopulate and destroy the habitat. This seems logical enough, but it is too simple to fully explain what goes on in nature. One thing to remember is that populations of predators and prey do not remain constant. There are many factors which cause their respective numbers to rise and fall.
Where Do Predators Live?
Predators can be found on any continent of the world. Hot desert climates, icy cold polar climates, rainforests, jungles, mountain tops, valleys, oceans, and lakes. Predators are found in nearly every habitat known to us.
Animals with an internal skeleton made of bone are called vertebrates. Vertebrates include mammals, amphibians, reptiles, birds, and fish.
Although vertebrates represent only a very small percentage of all animals, their size and mobility often allow them to dominate their environment.
Animals that do not have a back bone are called invertebrates. Invertebrates are cold-blooded — this means their body temperature depends on the temperature of their environment.
Some major groups of invertebrates include amoebas, sponges, jellyfish, corals, tapeworms, flukes, insects, arachnids, crustaceans, mollusks, and echinoderms. There are more species of invertebrates than any other group on the earth. Learn more about invertebrates and find out about the kinds of animals that fall into this category by visiting The National Wildlife Federation.
Did you know there are even plants that are “meat-eaters”? The Venus fly trap is one you've probably heard of. They are small plants found in North and South Carolina. They grow in nutrient poor soil, so they need insects to provide what they need to survive.
In Idaho, we have two carnivorous plants, sundews and bladderworts. They can be found in bogs near wetlands. Each plant has unique ways to catch and eat food. To learn more about carnivorous plants, visit botany.org.
The way a predator hunts, catches and kills food is determined by many factors such as the adaptations of the predator and the prey, and the type of habitat they live in. The strategies commonly used by predators are:
Hawks are among the many predators that catch their prey by chasing it. Chasing takes both time and effort to make a successful capture. To be successful, predators that chase their prey must concentrate on species that will provide enough nutrition to offset the energy burned while chasing. This is one reason why the hawk tends to eat more rodents and birds than grasshoppers. Grasshoppers just don't provide enough food value to justify the effort it takes to catch them.
Herons use a different technique, the stalk. Standing motionless in shallow water or wading slowly along the shore, the heron patiently searches for prey. When a heron sees its prey it captures it with a quick lunge of its long, sharp beak. This method does not require much energy. The downfall is the amount of time it takes to search for food. A stalking predator can afford to choose smaller prey and still meet its energy requirements.
The alligator prefers to lie still and wait. This method of hunting requires little effort, but chances of getting food are low. The cold-blooded alligator has minimal energy requirements. It can get by with infrequent meals. Most ambush hunters are fairly small because a successful ambush depends on the predator avoiding detection until it strikes.
Some animals hunt in teams. Wolves, lions, hyenas, coyotes and killer whales will usually live and hunt in family teams. Not only can they pursue larger and sometimes faster prey, but family groups can protect their little ones from other large predators. There's even a tropical insect that hunts as part of a team. South American army ants travel in the tens of thousands and devour every living thing in their path — insects, snakes, livestock, rats and mice. There aren't many creatures that can withstand marching army ants!
Tools of the Predators and Prey
Adaptations are physical characteristics or behaviors that help a plant or animal survive. Adaptations may help an animal move, reproduce, secure its food, or defend itself against its enemies. Brought together by a common need — to locate, subdue, and consume their prey — many predators display similar adaptations.
Vision is often the most important sense for a predator. A predator's eyes are usually located in front of its head. The forward location of the eyes gives an animal binocular-type vision. The area that each eye sees overlaps, so the brain receives two slightly different messages about the same scene. This helps a predator determine how far away prey is. It also tells the predator how fast its prey is moving.
Birds and insects must have the ability to catch prey in the air. A bird of prey's telescope-like vision can be eight times stronger than ours. Some predators rely on more sets of eyes than just one! Spiders and scorpions have clusters of six to eight eyes. Some of the eyes form the image. Others estimate distance, and still others detect motion. It's amazing though, even with eight eyes, a spider can only see about 1 foot in front of its face.
Predators which hunt at night (nocturnal predators) have special mirror-like structures in the back of their eyes. These structures help the animal to see in the dark. Deep sea animals have the same structures.
Most predators have a very good sense of hearing. In mammals, external ear flaps can be swiveled forward or backward in order to pinpoint the direction of a sound. The ears of bats are often highly specialized, with strange shapes that help catch the echoes of the calls they make as they fly. Birds can hear very well, too. Owls are thought to have the most outstanding hearing of any animal. Their ears are offset, which means one is higher than the other.
Some animals don't need ears to hear. Instead, they rely on vibrations they feel in their bodies. This is another way of pinpointing the source of sounds.
Ground vibrations from moving prey animals are transmitted through the bones of salamanders and snakes to the nerves near their ears. Sharks can monitor vibrations in the water with a lateral-line system. Fluid-filled canals lie just beneath the shark's skin along the sides of its head and body. The canals are filled with small pores open to the water. Underwater noises or motion cause a vibration that strikes these open pores. A shark tunes into the vibration and looks for its next meal.
Some predators can smell a meal from a mile away! Foxes are even able to smell food which is buried under two feet of soil. Some use their sense of smell to follow the footsteps or tracks of an animal.
A shark has outstanding smelling ability, but it works a bit differently. Their nostrils are not for breathing, but are used for sensing odor. Water flows in and out of the nostrils. A shark is able to identify the different smells found in the water from 2 miles away!
Snakes use their tongues to smell. You might see a snake flicking its tongue around. The snake is not getting ready to bite, it is smelling the air by picking up dust particles. These particles are carried to taste detectors in the snake's mouth. The taste tells snakes what animals are near.
How Predators Prey
Predators have different weapons that are used to kill and eat prey. The specific “weapons” they have are also considered adaptations. Three of a predator's main weapons are sharp teeth, claws and jaws.
The teeth are used to help kill the prey and are used as “knives and forks” while eating the prey. Most animals have three kinds of teeth.
In the front, you'll find incisors. These are used to cut food. On the sides, you'll see longer teeth, called canines, which are used for tearing chunks of flesh off of the prey. Canine teeth can also be used to kill the prey by piercing the neck or throat. Molars are found towards the back of the mouth. They are flat and strong and used to chew or grind. Some animals, such as crocodiles and sharks, have long, cone shaped teeth. These are used for grasping the prey and pulling it underwater. When underwater, the prey will drown enabling the predator to eat it.
Jaws, as well as teeth are important adaptations to seize and subdue their prey. Powerful muscles provide leverage and gripping power at the front part of the jaws. Some snakes are able to unhinge their jaws. This allows them to swallow a meal which is much larger than the snake's own head!
In some cases, beaks take the place of teeth. Each beak tells a story about its owner. Long beaks are used for probing, hooked beaks are for tearing, thick ones are for crunching seeds, thin ones are for picking insects. Beaks provide birds with a lightweight alternative to a mouthful of teeth. Like hollow bones, they are an adaptation for flying.
Sharp claws are also powerful weapons. Birds of prey have powerful claws, called talons, which help the raptor to grab its prey. Most big cats have claws that they use to grip and tear. They are able to pull in these claws when walking or running. This keeps them sharp. Moles and hedgehogs use their claws to dig up insects. In the same manner, grizzly bears dig up roots and burrowing rodents. Of course, on the grizzly, the claws are on the “tip of the weapon.” A grizzly's powerful paw can bring an animal down with one swipe.
Some predators use their tongues as effective weapons. A chameleon has one of the fastest tongues. It shoots its sticky tongue, which is coated with a glue-like substance, out towards the prey to capture it for swallowing. Did you know anteaters have tongues as long as a person's arm? This adaptation helps an anteater to reach areas where he or she needs to reach.
Another hunting weapon is poison. Snakes use their poison, which comes from their fangs, to paralyze or kill their prey. A spider releases strong digestive enzymes that turn their prey's insides to liquid. A straw-like mouth enables the spider to suck up the liquid. Wasps and scorpions paralyze their prey by using powerful stingers. A jellyfish uses its deadly tentacles to inject venom into its prey.
Camouflage is an adaptation that is used both by predators and by prey. Nature provides many ways for animals to make themselves hard to see. Both predators and prey use camouflage. Prey use it to hide themselves from predators, and predators use it to keep their prey from knowing they're coming after them! See how camouflage works at The Exploratorium.
One type of camouflage is when an animal's coloring is similar to its surroundings. Now you know why desert animals are often brown and jungle animals are often green.
Another type is called counter-shading. A counter-shaded animal is darkest on the top of its body and lightest on the bottom. From a distance these animals seem to turn into one color and look flat.
A third type of camouflage is called disruptive coloration — this is patterns of strongly contrasting, non-repeating markings such as spots or stripes. A zebra has this type. Its stripes help it to hide when it is grazing near trees and bushes. Does a tiger have disruptive coloration? Why?
Here are some more camouflage stategies:
Some animals change color with the season. This helps them to blend in with their surroundings when their surroundings change.
Imitation, or mimicry, is another form of camouflage. This is when an animal looks like a member of another species or like an object in its environment, such as when a grasshopper mimics a dry leaf.
Bright coloration, which seems the opposite of camouflage, is another form of self-defense when used to warn animals to stay away. Brightly colored animals are often poisonous or have an unpleasant taste.