Focus: Trees that provide habitat requirements for plants and animals.

Objective: To investigate the interrelationships between trees and the animals that inhabit them.

Materials: Hand lenses, paper, pencils. clipboards.

Procedures:

Locate several different types and sizes of trees. Ask the students to observe the trees for evidence of animal inhabitants: insects, birds, and small mammals. Look for evidence of animal homes. Insect homes include willow galls, oak balls, borings in the bark tent caterpillars, bag worms, leaf rollers, carpenter ants. Try to investigate each tree with as much detail as possible. Use a hand lens to note the smallest details. Have the students record their observations with drawings and notes. Ask the students to make two columns on a piece of paper, one for drawing the animals they see and the other for recording the number of each kind (species) of animal they observe. Discuss the role the tree plays in each of the animals' lives. Discuss how the animals and plants contribute to changes in the tree. Which changes may be beneficial or detrimental to the tree? Repeat the process above, but use a tree snag instead. Then discuss:

• Are live trees used by different animals than those which use dead trees?
• Which animals prefer live trees to dead trees?
• What value might dead trees have in a forest?
• How are dead trees similar to live ones? How do they differ?

Activity Extension:

Have the students mark off two square areas of equal size with string, one in the shade of a tree they have just investigated and the second nearby in the sunshine. Ask the students to count as many insects as they can find within each area. Hand lenses may be helpful. Compare the total number found in the shade with the total found in the sun. Math terms such as "equal to," 'greater than," and 'less than" may be introduced. Discuss:

• What influence does the shade have on the number of insects found?
• Do insects appear to prefer to work in the shade or the sun?
• What influence does the shade have on the activity of insects observed?
• Are they more active, less active, or about the same in the sun?
• Is there a difference between the species present in the shade and those in the sun?