Lesson 4: Interactions

Focus Questions

• How do the physical structures of predators help them find food?
• How are some prey able to survive?

Concepts to Discover

• Students will understand the importance of physical and behavioral adaptations in predator-prey relationships.

Procedure

1. Students form a wide circle. One student is chosen to be the bat and is blindfolded; 3 to 5 students are chosen to be moths.

2. With the bat and moths in the center of the circle and all the other students quiet, the bat will try to tag the moths. The bat uses its sonar (sound waves) to catch the moths. Every time the bat says “Bat!” the moths must respond by saying “Moth!” Tell the moths that every time the bat calls out “Bat,” it’s his radar signal hitting them. He sends out the signal to see if there’s anything out there. His cry bounces off the moths and returns to him like a radar signal. The return signal is the word “moth” that the moths shout.

3. Play the game for a few rounds, and then discuss which attributes make for a good bat (use sonar often, listen carefully for the moths) and which attributes help the moths (small, fast, low to the ground).

Suggestions

For younger students, use a list of actions to give the moths suggested ways to move (without letting the bat know what they are) so that the behavioral adaptations will be more explicit. See if older students can watch for and name the adaptations that work without giving them suggestions.

Background Information

Birds usually nest where there is available food. During the breeding season, they must have a constant supply of food so their young will survive. Some birds establish territories in order to assure their food supply. Birds that do not compete for the same food can coexist in the same territory.

Although food may be plentiful, providing food for growing young is a stressful time for parent birds. At first, the nestlings require constant protection. One parent remains at the nest while the other searches for food. As the young mature, there is less need for protection but a greater demand for food.

When the young leave the nest, they are not skilled in flight and continue to be fed by their parents. At this time, baby birds may appear to be abandoned, but, in fact, they are closely observed by their parents.

Focus Question

• How do young animals get enough food to survive?

Materials

• Worksheet 4: Birds in the Nest (This activity and the diagram on the Worksheet have been adapted from Bridges to the Natural World: A Natural History Guide for Teachers of Grades Pre-K through 6, by Patricia F. Kane, Dale A. Rosselet, and Karl Anderson, published by the New Jersey Audubon Society, which has granted permission to Mpala Live! for use in its lesson plan on animal interactions.)
• one paper cup (representing a nestling) for each student: 4 per nest
• 4 bowls to hold food supply
• 80 berries (or raisins, popcorn, gummi worms, etc.)
• hoops or string to define each nest site

Pre-Planning

Each nest will be made up of two parents and at least four nestlings. With a class of fewer than 24, reduce the number of nest sites and food sources.

1. Prepare the food supply by placing 20 pieces in each bowl.

2. Set up the activity’s playing area (see Worksheet 4). Place a hoop or circle of string to designate four nest sites. Place a food bowl at each food supply corner.

Procedure

1. Divide the class into teams. Assign two parents and four nestlings to each team. Let the students decide what kind of bird their team will represent.

2. Using the diagram, place the students at “nest sites” and show each team the location of its food source. Each team may take food ONLY from its assigned bowl.

3. Demonstrate the procedure by walking one team through one round before the game begins.

4. At your signal, one parent runs to the assigned food supply, picks up a “berry,” eats it, then carries a berry back to a nestling. When the first parent returns, the second parent leaves the nest to gather food while the first guards the nest. The parents take turns in the gathering and feeding. (With a very large class, the teacher may assign a food monitor to make sure the parent birds take only the prescribed amounts.)

5. The nestlings should invent sounds or motions to attract the attention of the parent with the food supply. The parents should feed the most insistent nestling. Nestlings may not eat the food until the game is over; they must keep it in their cup.

6. After a few rounds, the teacher stops the game and says, “As the nestlings grow, they don’t need as much protection but they need more food. Now both parents may leave the nest to gather food.” The first team to use up their food supply wins the game. At the end of the game, have the nestlings count their food units.

7. Questions for Discussion:

• Which parent supplied the greatest amount of food to the nestlings?
• Which nestlings got the most food? The least?
• Why did some nestlings get more than others?
• How did the parent birds know which young to feed?
• What else did the parents do for the young besides feed them?
• List the tasks of the parent birds (protect young, get food for the young and for themselves, fly back and forth from the nest to the food supply). Arrange the tasks from easiest to hardest. Which caused the most stress?
• At what stage of the nestlings’ development are both parents most active?
• How is bird behavior different from human behavior in caring for young? (Humans care for young equitably. A weak child will receive special care to help make it well and strong.)

Variations

• Put twice as many (40) food units in each bowl.
• Distribute the food unequally. Have students make up a story about how this happened (drought, frost, human development).
• What will happen next year? Explain. (Weather will improve, birds will find a new place to nest, people will develop backyard habitats for wildlife.)
• Move food sources closer to or farther away from the nests.
• Introduce a predator/human intruder into the game, standing between a nest and a food source. The parent may not move if an intruder is blocking the path. The intruder may move to block parents at any of the nests. How does this affect the parents? How did the intruder affect the food supply of the young?

Procedure

1. For parts 2, 3, and 4 of this activity, make copies of Worksheets 1-3 (Eat or Be Eaten: Producers; Eat or Be Eaten: Consumers; Eat or Be Eaten: Decomposers). Have students work in teams and refer to the animal cards created in the Square of Life Investigation in Unit 1, Lesson 1.

2. Identify the producers in each square of life. Producers are the vegetation; they create their own energy from sunlight. They do not need to eat, or consume, other living things in order to survive.

3. Identify the consumers in each square of life. Consumers are animal populations; they eat, or consume, other living things in order to gain the energy they need to survive. Primary consumers feed on vegetation. Secondary consumers feed on the primary consumers. They are called predators because they prey on, or hunt, other animals.

4. Identify the decomposers in each square of life. Decomposers are plants and animals that consume and break down dead plants and animals and return them as organic materials that go back into the soil. This group includes organisms such as bacteria, worms, insects, and fungi.

5. The relationships between these groups create a food chain.

​Play Eco-Connection (see Worksheet 5: The Eco-Connection), which appears in Bridges to the Natural World: A Natural History Guide for Teachers of Grades Pre-K through 6, by Patricia F. Kane, Dale A. Rosseet, and Karl Anderson, published by the New Jersey Audubon Society. The publisher has granted permission to MpalaLive! to reprint this activity to help students recognize the variety of interdependencies within a habitat.