Major Funding The Laura Moore Cunningham Foundation

Food Web: Top 10 Questions

March 2015

Thanks to Adare Evans, Wildlife Educator, Idaho Department of Fish and Game; and Dr. Holly Holman, Veterinarian, Zoo Boise for the answers.

1: What is the purpose of the food chain?

A food chain is when animal A eats animal B, then animal B eats animal C, which eats another animal and so on until you reach the top animal in the chain. The food chain gives us an idea of how energy and nutrients flow through the environment. It helps us because if one animal is discovered to have a strange chemical in it, we can determine where the chemical originated. What food did they consume that was contaminated with something they should not have had. For example, the peregrine falcon, which was declining in population, was detected with DDT. DDT was used to help control the insect population in order to help plants grow. Birds were eating insects, and the insects were eating plants that had been sprayed with DDT. Without looking at the animal’s food chain, we never would have known that. The food chain helps us see how everything is connected (From Jonah at Basin Elementary School in Idaho City)

2: Why is it called the food web?

It is called the food web because when you interconnect the food chains, they make a spider-like pattern (From Helena at Basin Elementary School in Idaho City)

3: What are decomposers?

Decomposers are usually small animals or organisms that eat the dead stuff left behind. They are things like bacteria, fungi and mold. For instance, they may eat a dead fish that is decomposing and turn what they eat into micronutrients that go into the soil. This makes energy that plants use so they can grow. Without decomposing, there wouldn’t be all the micronutrients that plants use to help them grow (From Samuel at Dalton Elementary School in Dalton Gardens)

4: How are food chains and food webs different?

Food chains are a linear model showing how energy transfers within one organism to the next. The food web shows how the energy is transferred among many different organisms, showing the web-like pattern. Food webs show how different organisms are connected with one another. Look at a salamander and a wolf. It may not seem like they are connected, but a salamander is in the water and eats aquatic insects. The insect it eats may have eaten a cattail. The wolf eats moose, and the moose may have eaten cattails (From Jaden at Galileo Stem Academy in Eagle)

5: What is at the top of the food chain for the whole world?

There is not one particular animal that is at the top of the chain. However, there are several large predators that we think of when thinking about the top like lions, tigers and bears. Humans are also at the top. Ultimately, there are a wide variety of animals that are at or near the top of their food chain (From Benjamin at Cynthia Mann Elementary School in Boise)

6: Is water part of a food web?

Water is found in living things. If you consider it that way, then the answer is yes (From Charles at Galileo Stem Academy in Eagle)

7: Is the grizzly bear on the top of the food chain?

The grizzly bear is one of the animals on the top of the food chain. They are omnivores, meaning they eat both animals and plants (From CJ at Basin Elementary School in Idaho City)

8: When plants and animals die, which organisms help to return nutrients to the food chain?

The animals that return nutrients to the food chain are the decomposers. You also have to look at scavengers, which are animals that may eat a magpie or a worm. They are also returning, through their poop, all those nutrients. So it’s the scavengers and the decomposers together that help to break down a dead animal and return nutrients to the food chain (From Aliany at Rochester NY School #25 in Rochester, New York)

9: Do animals eat lots of different kinds of animals?

Yes. Animals eat all different kinds of animals. This leads to proteins, minerals and vitamins that are broken down into their bodies, as well as ours. They get everything they need to live the different things that they eat (From Audrey at Galileo Stem Academy in Eagle)

10: Are there keystone animals in the food web?

A keystone animal is one that is so important because it holds the whole environment together. A salmon is a keystone animal for Idaho. Salmon are important because they travel. Idaho’s salmon go to the Pacific Ocean and there, they eat tons of plankton. They fill up on krill and come back to Idaho, bringing back all of those nutrients. Salmon feed so many animals. They feed people, otters, muskrats, bears, raccoons and more. Believe it or not, we can see it in the growth rings of trees when there has been a good salmon year. Salmon, for Idaho, is a keystone species because they are a part of so many food chains (From Harrison via the Internet)

March 2010

Thanks to Evin Oneale, Conservation Educator, Idaho Department of Fish and Game; and Adare Evans, Wildlife Educator, Idaho Department of Fish and Game for the answers.

1: If a predator stalks poisonous prey, would the predator be poisoned?

It depends on the predator/prey relationship. Some predators build up immunity to their prey even though the prey may be poisonous to other animals. Predators learn pretty quickly what is edible and what they should stay away from. (From Jordan in Mrs. Hudson's class at Dalton Elementary School in Dalton Gardens.)

2: Are there any living things, besides green plants, that make their own food?

Some of you wanted to know if it all starts from the sun, but there are bacteria in the ocean that use minerals from hot deep sea vents. They start the food chain there in the pitch black and start energy from minerals. It's amazing! (From Abbey in Mrs. Hudson's class at Dalton Elementary School in Dalton Gardens.)

3: What is photosynthesis?

In very simple terms, it's a process whereby plants take the energy from the sun and convert it into food. (From Mrs. Woodall's class at Dalton Elementary School in Dalton Gardens.)

4: Is poop considered part of the food chain?

Yes, there are animals that eat poop. Some take it and use it for their own energy. (From Mrs. Woodall's class at Dalton Elementary School in Dalton Gardens.)

5: Have typical food chains been altered drastically over the last few decades? If so, why?

Yes, there have been alterations to food chains, particularly in the last 100 years and mostly related to human impact. Certain habitats have become extinct or greatly reduced. There's probably not a food chain out there that hasn't been altered somehow by people. (From Mrs. Hunt's class at Cynthia Mann Elementary School in Boise.)

6: Does the food chain have arrows?

Arrows are used to show food webs, but the arrow is not really part of the food chain. It's a graphic and shows the direction of energy flow. If you see a diagram and there are all these different plants and animals there, the arrows show which way the energy flows. In other words, who will eat what and what that will eat. (From Isaiah in Mrs. Brando's class at the Northwest Children's Home Education Center in Lewiston.)

7: Are insects a big part of the food chain?

Absolutely! There are more insects (about a million different species of insects) living on this planet than there is anything else. Insects eat plants, are eaten by things and pollinate flowers. This helps bring us fruits and vegetables and makes them a big part of the food chain. (From Gabriel in Mrs. Nicolescu's class at Riverside Elementary School in Boise.)

8: Where do fungi (mold, mushrooms, etc.) fit in the food chain?

Fungi are decomposers. They feed off dead rotting material and use it for themselves. It's interesting as you can look at decomposing as the beginning of the food chain or the end of it. Fungi are very important because they break down the nutrients for the plants to reabsorb and start all over again. (From Colton in Mrs. Bramlet's class at Pathways Middle School in Meridian.)

9: Why does the food chain start with the sun?

The sun is that initial source of energy that allows things to produce. They couldn't do it by themselves. Without that first source of energy, energy can't be passed along. (From Conner in Mrs. Woodall's class at Dalton Elementary School in Dalton Gardens.)

10: What animal is at the bottom of the food chain?

We start with a source of energy, either the sun or the really hot deep sea vents. Then we have plants that use that energy. Animals eat those plants and those animals may be eaten along the chain and they die and decompose. You can look at those decomposers as the end or the beginning. It all depends. The chain is really a web that's all interconnected. (From Michael in Mr. Wing's class at Marsing Middle School in Marsing.)

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