Ancient predators in a modern world.

• Position: Crocodilians

An exhibition exploring the complex lives of crocodilians--the group including crocodiles, alligators, caimans, and gharials--their evolutionary history, biology, behavior, and precarious relationships with human societies is on view at New York's American Museum of Natural History.

Crocs have flourished for more than 200,000,000 years, once including a rich diversity of specialized forms from galloping land predators and jumping insect-eaters to pug-nosed herbivores and dolphin-like pelagic hunters. Modern crocodilians mostly are built for the water's edge. These stealthy aquatic predators have rugged bodies, keen senses, and incredible strength. They also lead intricate social lives: communicating with a range of pips, grunts, hisses, bellows, and subtle changes in body posture; battling over territories; engaging in lengthy courtship rituals; and providing their young with parental care.

Living crocodilians range from diminutive forest dwellers to behemoths that eat wildebeests, bison, and, occasionally, people. In a human-dominated world, the future of crocodilians depends upon our willingness to share space with these large predators.

Live creatures visitors will encounter in this exhibition are the Siamese crocodile (among the most endangered crocodilian species); the American alligator (females of this species are serious about motherhood, standing guard for two months...