Predator and Prey, (nouns, “PREH-duh-tor” and “PRAY”)
The words “predator” and “prey” describe the roles in a relationship between two species. In this relationship, one species eats the other. The predator is the species that does the eating. The prey is the one that gets eaten. Predator/prey relationships are important links in food webs. These links move energy and nutrients through an ecosystem.
A bear fishing salmon from a river is one example of a predator/prey relationship. The bear is the predator. The salmon is the prey. But salmon must eat too. They snack on plankton, insects and other small critters. So in those cases, the salmon plays the role of predator.
Animals aren’t the only predators and prey. A rabbit chomping on grass is a predator, while the grass is its prey. But plants can also play the role of the predator. For example, a Venus flytrap (Dionaea muscipula) snares flies in its leafy jaws and digests them.
Predators and prey drive each other’s evolution. Over time, predators adapt to better catch prey. For example, the cheetah’s powerful body can out-race its impala prey. But prey have evolved ways to avoid being eaten. The nimble impala can make a hard swerve that leaves behind the cheetah. Many plants have toxins, spines or other defenses that make eating them unpleasant. And millions of years ago, the need to escape marine predators likely helped drive some species from water to land.
In a sentence
Thanks to its predator/prey relationship with ants, the Australian ant-slayer spider (Euryopis umbilicata) evolved a cool somersault technique for capturing prey.
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Power Words
More About Power Wordsdefense: (in biology) A natural protective action taken or chemical response that occurs when a species confronts predators or agents that might harm it. (adj. defensive)
digest: (noun: digestion) To break down food into simple compounds that the body can absorb and use for growth. Some sewage-treatment plants harness microbes to digest — or degrade — wastes so that the breakdown products can be recycled for use elsewhere in the environment.
ecosystem: A group of interacting living organisms — including microorganisms, plants and animals — and their physical environment within a particular climate. Examples include tropical reefs, rainforests, alpine meadows and polar tundra.The term can also be applied to elements that make up some an artificial environment, such as a company, classroom or the internet.
evolution: (v. to evolve) A process by which species undergo changes over time, usually through genetic variation and natural selection. These changes usually result in a new type of organism better suited for its environment than the earlier type. The newer type is not necessarily more “advanced,” just better adapted to the particular conditions in which it developed.
food web: (also known as a food chain) The network of relationships among organisms sharing an ecosystem. Member organisms depend on others within this network as a source of food.
insect: A type of arthropod that as an adult will have six segmented legs and three body parts: a head, thorax and abdomen. There are hundreds of thousands of insects, which include bees, beetles, flies and moths.
link: A connection between two people or things.
marine: Having to do with the ocean world or environment.
nutrient: A vitamin, mineral, fat, carbohydrate or protein that a plant, animal or other organism requires as part of its food in order to survive.
plankton: (sing. plankter) Small organisms that largely drift or float in the sea. Depending on the species, plankton range from microscopic sizes to organisms about the size of a flea. Some are tiny animals. Others are plant-like organisms. Although an individual plankter is very small, these organisms often form massive colonies, numbering in the billions. The largest animal in the world, the blue whale, lives on plankton.
predator: (adjective: predatory) A creature that preys on other animals for most or all of its food.
prey: (n.) Animal species eaten by others. (v.) To attack and eat another species.
salmon: A popular game fish that tends to live most of its life in the ocean, then enters coastal rivers (and freshwater) to breed and lay eggs.
species: A group of similar organisms capable of producing offspring that can survive and reproduce.
toxin: A poison produced by living organisms, such as bacteria, algae and certain plants (such as poison ivy). Bees, spiders, snakes and other animals also produce toxins. These are referred to as venoms.
About Katie Grace Carpenter
Katie Grace Carpenter is a science writer and curriculum developer, with degrees in biology and biogeochemistry. She also writes science fiction and creates science videos. Katie lives in the U.S. but also spends time in Sweden with her husband, who’s a chef.
