Camouflage in Insects due to Seasonal Changes in the Color of Ground Cover
Project Idea by: Tyler Halpern
Camouflage is a disguise caused by similarities between the colors and patterns of an animal's body and those found in its environment. Animals with colors that blend in with their background are said to be camouflaged. Camouflage protects animals from predators (animals that kill and eat other animals). For example, a bird that feeds on grasshoppers will have trouble spotting a green grasshopper on green grass. Coloring that helps to camouflage an animal from a predator is called protective coloration.
Earth's temperate zones include most of North America, Europe, Asia, and the southern parts of South America, Africa, and Australia. In the temperate zones, there are four divisions of the year called climatic seasons (divisions of the year based on average temperature and the amount of time that the Sun is in the sky each day): winter, spring, summer, and autumn. Winter has the shortest days, meaning that the Sun is in the sky for the least amount of time each day. Winter also has the coldest days. Generally, there are few green plants in the winter. Most leaves are dead and more brown in color.
Spring follows winter with medium-length cool days. This is the most colorful season. Following spring the days get longer and warmer, leading into summer, with the longest and hottest days. Summer begins with very colorful plants. As summer progresses, the colors remain if the rainfall is good. Without rain many green grasses die and turn yellow or brown. Autumn follows summer. Like spring, autumn has medium-length cool days. Each day of this season gets shorter and colder, leading to winter, when the cycle begins again. During autumn, leaves no longer produce pigment (some substances that provide color to a material). Without chlorophyll, the green pigment that disappears first, the yellow and orange pigments in the leaves can be seen for a time. Low temperatures and bright sunshine encourage the production of a red pigment for a time. A project question might be "How do seasonal color changes in the environment affect camouflage in animals?"
Clues for Your Investigation
Determine how seasonal changes in the color of ground cover affect which insect color is most camouflaged. Use colored bread pieces to represent insects. Ask an adult to prepare the bread pieces by trimming off the crust, then cutting each piece of bread into pieces of equal size. Soak the bread in different-colored water solutions made by mixing 1/4 cup (63 mL) water with 10 drops of food coloring. Use different colors such as red, yellow, and green. White can be the control. Soak the white bread pieces in water with no coloring so that they have the same texture as the colored pieces when dry. Since it can take 3 or more weeks for birds to find a new feeding area, you may wish to offer birdseed for a period of time until the birds start to regularly visit your testing area.
Independent Variable: Seasonal ground color changes
Dependent Variable: Number of each color of bread pieces eaten by birds
Controlled Variables: Same type, size, and number of bread pieces of each color for each testing, equal testing times, same time of day, same testing location
Control: Uncolored bread pieces
Other Questions to Explore
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