Passage Summary: Tiny birds lay eggs that are quite heavy compared to their own bodies, while huge birds lay eggs that are a very small fraction of their body weight.

Reasoning: Data points show that as the size and weight of an adult bird increase, the weight of its egg becomes a smaller percentage of the adult's total body weight.

Analysis: This stimulus presents a clear inverse relationship: the larger the bird, the smaller the egg-to-body-weight ratio. Since this is a 'Principle' question, we are looking for a general rule that matches this pattern. The ideal answer will generalize that as adult body mass increases, the relative proportion of the egg's weight tends to decrease. Focus on the mathematical relationship between the two variables provided.