Stories by David Crews

Animals have evolved a range of mechanisms to determine whether an individual takes on masculine or feminine traits. Cross-species comparisons offer some surprising insights into the nature of sexuality

An all-female species of whiptail lizards presents a unique opportunity to test hypotheses regarding the nature and the evolution of sexual behavior

In order to survive in the harsh environment of western Canada the red-sided garter snake has evolved a precisely timed cycle of physiology and behavior with several spectacular features

The green anole, often mistakenly called a chameleon, is a good subject for examining how the sex glands and the brain interact in orchestrating the sexual behavior of both males and females