Topics:

• ecology • evolution • natural selection • predator/prey • camouflage • adaptations

Concepts:

• Oragnisms are interdependent and are influenced by abiotic factors in their environment as well as biotic factors.

• Organisms change over time to adapt to changing conditions in their environment.

• Organisms survive by acquiring resources, mating, and not being preyed upon.

Skills:

• determining cause and effect • analyzing data • identifying relationships and patterns • predicting

Objectives:

Students will • simulate how predators use senses (sight, in this case) to find prey, • describe how a population can change over time by natural selection, • apply a simulated activity to real life

Materials:

• an area outdoors with grass • student activity sheets • a portable dry-erase or chalk board

Levels:

basic activity for 1 - 4 grades

activity with extensions for 5 - 12 grades

Time Considerations:

setup: 20 minutes

explanation: 15 minutes

activity: 20 minutes

discussion and activity analysis: 30 - 50 minutes

Overview:

Camouflage is an adaptation that enables species to survive. The students will experience being predators (flocks of birds) as they prey on colored macaronis (bugs). As predation and generations of time pass, they witness natural selection as the population of macaroni bugs change color composition.

Getting Ready:

• Assemble a zip-lock bag of 50 yellow, 50 green and 50 orange noodles per class group. Eight to ten pounds of tri-colored, spiral macaroni noodles is an adequate amount for 5 class periods.

If you are unable to find tri-colored macaronis, dried beans will work also. A modification can be to have navy, black and kidney beans on an asphalt surface. One of the beans must be the color of the ground played upon. Black beans would be the camouflaged bean because they are the color of the asphalt playing surface.

• One empty bag is needed per team (flock of birds) and for the three noodle collectors.

• Draw a table on the dry-erase or chalk board to keep data. Shown here.

Doing the Activity:

• Review the ecological concepts targeted. Grade school and middle-aged students enjoy the book How to Hide a Butterfly and Other Insects by Ruth Heller to warm up to the concept of camouflage. Discuss camouflage as a group and name some other animals that have these adaptations. What are the advantages of being camouflaged? How do animals get these adaptations?(genetic mutation and natural selection)

• Explain the "insect" found in the school lawn called a macaroni bug. It is a species of insect which resembles macaroni noodles. The macaroni bugs eat grass. Birds eat the macaroni bugs. A food chain to demonstrate this is grass › macaroni bugs › birds. The niche of the macaroni bugs is to reduce the amount of grass and provide birds with energy and nutrients. Macaroni bugs have three colors. Their body colors are yellow, green, and orange. When macaroni bugs have offspring they have twice as many of their same color variation. The color they are is dependent on their genes or DNA which is passed down to their offspring.

• For the younger age group, simply divide the class up into four different flocks of birds and have them observe the effects of their hunting on the population. Talk about camouflage as the overall concept.

• For the older age group, involve more of the ecological concepts and vocabulary by keeping data for multiple generations and evaluating the outcomes on the student activity sheet.

• Select three students to be the counters. They can be given the cards as descriptions of their job. They are to collect and count the number of their colored macaroni (yellow, green or orange) after each round of timed hunting. Select one student to keep the data. He/she will subtract the number of a specific color of macaroni originally in the lawn from the total eaten (collected). Then he/she will multiply the number by 3 and record this new colored population total on the board as the next generation.

• The other students will become birds. Divide them into three flocks with a leader for each. Explain that animals who use their sense to hunt the most survive. They will have two rounds of predating on the macaroni bugs and each time they must gather 25 bugs for their group in the 4 minutes. One bird will fly from the nest at a time, being careful not to step on any bugs or they are not edible. The one bird finds one bug and returns to the nest, dropping the bug into the bag to be counted. They need to rush and pick up the first bug they see.

• The students should be given the student activity sheets to review and complete the problem through materials and methods before they do the activity.

• Outside, arrange the teams in lines for a relay race and spread the noodles out in an area 10 meters from them. At "GO" the first birds will fly to get a bug. And "STOP" after 4 minutes. Seat the students in their lines, have the collectors of their specific colors count the numbers of macaronis. Calculate and record the population of the next generation.

• Return to the classroom and share the data for their student activity sheets. They will graph the data in a triple line graph and draw conclusions.