Hawks fly at very high altitudes, sometimes over water, and thus their flight behavior and migration patterns are extremely difficult to study. Now, based on nearly ten years of research, this book provides the most complete analysis to date of how hawks migrate. Paul Kerlinger has employed both direct observations and radar techniques to obtain a much more accurate understanding of the migratory behavior of hawks and the "decisions" they make in flight. And, he has integrated data on the flight behavior of raptors in general with information about their ecology, physiology, evolution, and nonmigratory behavior.

Kerlinger begins with an overview, discussing ecology and geography, research methods, natural history, and evolution, and atmospheric structure. He then addresses specific aspects of flight behavior: aerodynamics, morphology, mechanics, direction, altitude, flocking, water crossing, speed selection, daily distance traveled, and flight strategies. Kerlinger describes each aspect of behavior quantitatively, testing mechanistic hypotheses. In conclusion, he examines how migrants integrate these behavioral components. Throughout the text he draws comparisons between the migratory flight behavior of hawks and that of other taxa. By means of such comparisons, researchers can gain insight into the selective pressures that shape the behavior of migrant species.