What Is a Food Chain?

Transcription

1 During our ecology theme time, we have been exploring the question, "What is a food chain?" while looking at different habitats. On your recording sheet, you will show your understanding of and ideas about food chains. In the large circle, there are places to draw and label a food chain for each habitat. You will draw one food chain that ends with a herbivore and another food chain that ends with a carnivore. 1 of 12

2 Suggested Grade Span K 2 Task During our ecology theme time, we have been exploring the question, "What is a food chain?" while looking at different habitats. On your recording sheet, you will show your understanding of and ideas about food chains. In the large circle, there are places to draw and label a food chain for each habitat. You will draw one food chain that ends with a herbivore and another food chain that ends with a carnivore. Big Ideas and Unifying Concepts Interdependence Patterns Systems Life Science Concepts Populations and ecosystems Regulation and behavior Structure and function Science in Personal and Societal Perspectives Concept Populations, resources and environments Mathematics Concept Diagrams Time Required for the Task Approximately 60 minutes. Context This task is a culminating assessment of the concepts my first graders have learned related to food chains. They have been investigating a variety of food chains, in different habitats, during our eight-week study of Trees, Ecosystems and Recycling. This enabled them to draw upon 2 of 12

3 their prior knowledge from other units of study during the year ("Habitats in Australia" "The Water Cycle" "Ocean Interdependence" and "Wood, Pond and Field Habitats"). Vermont Native American history and storytelling were also integrated into their environmental studies to provide the children with an understanding of becoming good stewards of the earth. This investigation of food chains (and food webs) helps students form clearer connections to and greater respect for the delicate balance and diversity of plant and animals, and for the Native American perspective with its environmental messages. This unit of study also provides experiences to engage young children in their immediate environments. What the Task Accomplishes This investigation demonstrates how children apply their knowledge of the interdependence of cycles that affect plants and animals. They can see how important the roles of the sun, producers, consumers and decomposers are in keeping nature s balance on our earth. Children can see diversity, understand animal and plant adaptations, and make more accurate connections about different ecosystems by watching videos, sharing literature and having firsthand experiences in woods, fields and ponds near the school. Different inquiry activities allow the children to understand and appreciate patterns of similarity and difference among living organisms, and to become more aware of a hierarchy in food chains and food webs. How the Student Will Investigate Ideally, I want children to have first-hand experience in their investigations. Sometimes, if I can not bring them to the real environment, I try to bring the best examples or experiences to them. I usually integrate our ecosystem theme with the local Audubon Nature Center, which we were not able to visit this year. Instead, I used the schoolyard, neighboring woods, a local stream and a wonderful series of nature videos that demonstrated various real habitats to supplement the children s experiences. I have also been integrating more opportunities using guided imagery and drama to teach science concepts this year. Students had several opportunities to dramatize a variety of food chains in cooperative groups for wood, field, pond, backyard, arctic and desert habitats. I also used pictures of real types of wildlife (to hang on their backs) for a questioning game about animal attributes. The class could see the animal picture, but the individual wearing the picture could not. The child had to ask questions about the secret living thing to discover its food choice, shelter, movement, body characteristics, habits, etc. The class could only answer yes or no to the questions asked. After several weeks, I took the children into our computer lab to illustrate a food cycle of their choice (most chose a pond food chain), by independently using the technology to draw a big circle and organize at least four components necessary to their food chain. Later during the week, I provided a sheet with a large circle and lines spaced out for students to use to organize their food chain pictures. I also gave students a worksheet of black and white pictures of items to cut out and build a food chain for a pond habitat. This allowed more flexibility for those children who were not as comfortable with drawing. On a second circle, I asked each child to draw and label a different habitat with its food chain. 3 of 12

4 Interdisciplinary Links and Extensions Science There are wonderful and numerous resources that I like to use with these units. Some of the ones that I found useful included: Nature with Children of All Ages, by Edith A. Sisson; Keepers of the Earth, by Michael Caduto and Joseph Bruchac; Kids & Science: Woods, Ponds, & Fields, by Ellen Doris; The Food Chain, by Malcolm Penny; and any of the many Miss Frizzle books about habitats. Art The children made an environmental scrapbook about their activities. These included the technology food chain; leaf rubbings; A Tree is an Apartment outdoor investigation; birch-bark outlines of canoes with written information about the Abenaki (Indians native to Vermont) on local rivers and Lake Champlain; a tree haiku; My Favorite Tree song; a painting to represent Robert Frost s Swinger of Birches poem; and a sheet with three circles to sketch at least three different types of wildlife like the naturalist Jim Arnosky from a Reading Rainbow video, Raccoons In The Corn. Social Studies The environmental theme integrates very nicely with Native American cultures. Keepers of the Earth and Keepers of the Animals, by Michael Caduto and Joseph Bruchac, provides many storytelling activities that can be done in the classroom or outdoors. Thirteen Moons on Turtle s Back, by Joseph Bruchac and Jonathan London, is a beautiful book that integrates poetic form and art for projects about how Native American cultures kept track of the seasons. The book illustrates how to care for fragile Mother Earth. Recycling is another important concept that fits with these investigations. The children have a center that has objects that can decompose, as well as objects that are not healthy for the earth. They have a booklet to sketch the object found, label it, and record whether it will decompose or need to be recycled. Language Arts Using Tomie Depola s new book, Water, I had the children make a booklet of their own using watercolors to illustrate different forms of water. Start with a sentence such as, Water is... a bubbling stream.. Ask students to use that sentence as a pattern to write other sentences such as "Water is... a clear, cool waterfall. ; Water is... dewdrops on blades of grass. Writing haiku is another easy way for children to connect with environmental themes. We also used our big partners (fifth graders) to practice using the five senses to write poetry in free verse. The children made watercolors, on large circles of what they would do with their favorite tree. Turtle In July, by Marilyn Singer, illustrates for each month of the year different wildlife that are typically found in Vermont. This is another example of the excellent literature that can be integrated into science. 4 of 12

5 Movement Children can use their bodies to tell the story of the life cycle of a frog, the life cycle of seeds, seed dispersal, the water cycle, food chains, weather and other concepts. Reading a guided imagery as a narration for the movement activity is another option. Mathematics Partners or teams can investigate a particular tree in the schoolyard, using a recording sheet and measuring tapes to collect the following data: the height of a small tree, the circumference of a tree at different heights and the length of the shortest and longest branches. Students could also describe the leaves (deciduous) or needles (coniferous) on the tree, count the needles on a stem, or find a team whose tree is bigger or smaller than their team's tree. Children can also locate and count how many trees seem similar to their particular tree. Mapping skills can even be integrated by identifying where certain species of trees are located. Music There are many environmental songs that can be integrated into the classroom activities, including Raffi s Evergreen, Everblue and Piggyback Planet, and Tracy Wolters' Vermont Songs For Kids. Children like to write their own raps for environmental concerns and create songs about recycling, trees, the water cycle, worms and other related topics, using familiar nursery rhyme tunes. Teaching Tips and Guiding Questions Some questions that can be asked during the food chain investigations or environmental theme might be: What characteristics do herbivores, carnivores and omnivores have that are similar? different? Describe the role of producers. Where are they in the food chain? Describe the role of consumers. Where are they in the food chain? What role does the sun play in food chains? If you dig up healthy soil, what population of worms would you find and why? Does this material you have dug up decompose or need to be recycled? Why do you think so? How did Native Americas gather from the earth? What did they hunt in our state? How did they make use of the environment for traveling and tools? How did they keep from wasting what was hunted? Do all food chains end with a carnivore? Give an example of one that does not. How does a food chain in Australia compare to one where we live? Why is a tree considered an apartment for its inhabitants? Can you see any patterns in food chains? How would you describe them? 5 of 12

6 Concepts to be Assessed (Unifying concepts/big ideas and science concepts to be assessed using the Exemplars Science Rubric under the criterion: Science Concepts and Related Content) Life Science Structure and Function; Regulation and Behavior: Students identify characteristics of organisms and categorize living things as plant eaters or meat eaters, producers or consumers. Students use the terms producer, consumer, meat eater, and plant eater appropriately. Life Science Populations and Ecosystems: Students describe the interdependence of plants and animals in food chains and determine some patterns of plant eaters, meat eaters and decomposers in the food chain. Science in Personal and Societal Perspectives Populations, Resources and Environments: Students recognize that human activities have an impact on natural systems and that changing human behaviors can lessen the impact on ecosystems. Mathematics: Students use diagrams appropriately. Skills to be Developed (Science process skills to be assessed using the Exemplars Science Rubric under the criteria: Scientific Procedures and Reasoning Strategies, and Scientific Communication Using Data) Scientific Method: Observing, predicting, recording data, manipulating tools, drawing conclusions, measuring, communicating findings, challenging misconceptions and raising new questions. Other Science Standards and Concets Addressed Scientific Theory: Students look for evidence that explains why things happen and modify explanations when new observations are made. Life Science Structure and Function; Regulation and Behavior; Evolution, Diversity and Adaptations: Students describe and group animals by what they eat and where they live. Students understand that living things are found almost everywhere in the world and are interdependent. Science in Personal and Societal Perspectives Populations, Resources and Environments: Students recognize that human activities have an impact on natural systems; changing human behaviors can lessen the impact on ecosystems. 6 of 12

7 Suggested Materials I provide a wide variety of large pictures showing wildlife in different habitats (pond, field, lake, river, ocean, desert, tundra, forest, etc.), use high-quality videos that represent familiar habitats if field trips are not available, and take students on walks around the school neighborhood to observe plant and animal life. We also take a field trip to nearby streams, woods and ponds to get first-hand experiences of food chains. We simulate food chains with small plastic plant and animal toys on paper plates. For the actual assessment task, students need a recording sheet and pencil or drawing materials. Possible Solutions Each child should be able to illustrate two different food chains. (I asked the students not to use the pond, because we had already done a lot of activities and assessment around this habitat.) I was also looking for connections to prior units of study as well. I asked the students to begin their drawings with the sun (which provides energy for the plants to grow), with the last drawing indicating the top of the food chain. Task-Specific Assessment Notes Novice This student is clearly confused in his or her understanding of food chains, although the animals depicted could live in the same habitat. (For example, the sun, plants and ants can be considered to be in the correct sequence, but the tree is eating the ants and the bear is eating the tree, which is scientifically incorrect.) The second example is also incomplete and confused, (i.e., The sun provides energy for the bear, the fish eats the bear, and the ants eat the fish.) We had talked about decomposing, but when this student is interviewed, s/he demonstrates no understanding of this concept. Apprentice This student starts out with an appropriate strategy but does not illustrate a successful sequence with the pictures that are chosen. (For example, the sun and cattails, which represent plants, are correct. The use of frogs and fish eating the plants skips the role of insects. The hawk could eat a frog or a fish, and a hawk could be a predator of the fish. Raccoons would not be a predator of hawks in the food chain, nor would the ocean crabs be at the top of this food chain.) This student has only a partial understanding of food chains and habitats. The second example shows a better understanding of food chains, but both examples are not supposed to represent ponds, which demonstrates a lack of successful connections in the assessment. The second food chain of a pond is accurate, using a person at the top of the food chain based on his or her personal experience. Practitioner This student has a clearer understanding about food chains. There are two different examples which have complete solutions. The first food chain illustrates a correct sequence (e.g., sun, seeds, chipmunk and owl), an effective use of pictures, and a connection to an earlier study of 7 of 12

8 owls during the year. The second food chain is correct with the bear at the top of the food chain. (We talked about a variety of bears and their food preference.) When asked about the use of a caterpillar as opposed to other insects, the response was, It is floating on the stream on a leaf and the fish jumped to eat it. Expert Using a carnivore and an herbivore, this student provides two clear examples to represent a food chain. One food chain representes an accurate sequence from the sun to plants, nuts and berries, to the chipmunk, to the fox at the top of the food chain. When asked if one could go further the student replies, Only with people that used to have fox hunts that were kind of cruel or maybe rabies could be a factor. This demonstrates sophisticated thinking, vocabulary, and extending ideas for a first-grade student. The second food chain represents the deer at the top of the food chain with a successful sequence. When this student is interviewed further, s/he indicates that, A wolf or coyote pack would hunt a young or sick deer, if you were to go further up the food chain. 8 of 12

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