Being cold-blooded, crocodiles can maintain their body temperatures through the environment (such as basking in sun and bathing in rivers). Their basal metabolic rate is so low that at rest, they could stay a long time without food. This way they can survive with only a few meals a year.
Crocodiles have an indiscriminate taste for prey. Therefore their digestive systems have adapted to digest and consume a high variety of ingested food. This allows the crocodiles to survive in any environment with any type of prey.