Analyze and Conclude
1. Calculate Suppose there are 1000 units of
energy available at the producer level of the
energy pyramid. Approximately how many units of energy are available to the third-level consumer?
66 Chapter 3 • Lesson 3

An ecologist studied the same species of deer during the summer and the winter. she noticed that during the summer, when there was plenty of food, the deer were energetic and playful. however, during winter when food was scarce, the deer moved more slowly and did not run unless they needed to escape a predator. which scientific fact is best supported by her observations?