Students will be able to:
- Explain the basic concepts of food chains and interdependency.
- Communicate the impact of the extinction of a species on other species.
Students learn about the food chain and use blocks to build a food chain pyramid. Students discuss the extinction of species and the effect this has on other living things in the pyramid.
Change, communities/ecosystems, critical thinking, cycles, diversity, interdependence, and energy.
Science, creative arts, and language arts.
Food chain, species, endangered, extinct, interdependence, predator, prey, herbivore, carnivore, omnivore, producer, and consumer.
Animals and plants are becoming extinct at the average rate of one species per day on earth. We do not know what the effects of this mass endangerment and extinction might have on the earth over time. When we lose any species, there is a direct impact on the food chain. The interdependence of living things is very complex. Organisms that do not feed or directly rely on the endangered or extinct organism can still be impacted by the change. For example, if all of the mountain lions are lost in one area, we may also lose a species of butterfly as a result. Humans may also someday be threatened by extinction due to this complex interaction between species.
One block per student, paper cut to fit the size of one side of each block, tape, and markers or crayons.
- Begin by making sure each child is familiar with the vocabulary above. Choose one particular habitat such as forest, river, or ocean. Each student chooses one plant or animal that lives there. Magazines and other publications can provide ideas and stimulate interest in a variety of species. Make sure that students choose plants and animals including producers, consumers, herbivores, carnivores, omnivores, predators, and prey. Be sure to include our own species as well – Homo sapiens. Each student researches their organism and determines which category or categories that his or her organism belongs to.
- Each student writes the name of his or her organism and/or sketches it on the piece of paper and tapes it to one of the blocks.
- Build a "food pyramid" with the blocks, beginning at the bottom with the plants or producers and working up through the consumers – herbivores, omnivores, carnivores/predators, and scavengers. (You may choose to include or leave out the decomposers for simplicity.) Organisms are placed above the organism they eat. It should look something like this:
/ ––– Scavengers ––– \
/ –––– Carnivores –––– \
/ ––––– Herbivores ––––– \
/ –––- Plants/Producers –––-\
- Ask one student to remove a block, stating that this animal has become extinct and no longer is part of the food chain. At times, no blocks will fall; other times, a few blocks may fall. Continue to remove blocks observing what happens each time one species is removed. Using this visual activity, you can generate a class discussion on what the implications are for this in the natural world. Why do other blocks fall when one is removed? Can any one species exist alone in the world?
Adapted with permission from: Environmental Education Curriculum Packet: Ideas and Activities. Didier Gincig, 1991.
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