Fossil evidence suggests that reptiles and amphibians each dominated the land at various times in the history of the earth. Today, these creatures appear far smaller than their ancestors looked millions of years ago.
Both amphibians and reptiles are vertebrates. Amphibians spend part of their life in water, while reptiles do not. Amphibians include salamanders, toads and frogs. Reptiles include alligators, lizards and snakes. Both reptiles and amphibians are cold-blooded; they cannot produce their own body heat, so they must seek out the sun's heat to warm them up. Reptiles live in dry habitats where amphibians cannot. Some amphibians, such as the Eastern box turtle, may live more than a century.
Since amphibians and reptiles do not need to burn calories to make body heat, they eat far less food that birds and mammals of the same size. Many amphibians eat insects. Some reptiles eat insects as well as birds and other animals. Anacondas go several months between meals. The emerald tree boa hunts at night, using infrared heat receptors to find birds or small mammals in the dark. Snakes use these receptors, located in pits along their lips, to find prey in their environment that differs in temperature.
Loss of habitat, road mortality and collection of the creatures for use as pets head the list of reasons for the decline of amphibians and reptiles. Pollution and predation also add to the problem. Since reptiles and amphibians do not move as fast as mammals and birds, they often get caught by barriers that stop them from returning to areas they used to live in. Becoming more aware of the habitat requirements of amphibians and reptiles helps humans learn to better live with and help them. Some states regulate the collection and sale of reptiles and amphibians, with strict penalties for violations.
Reptiles and amphibians act as strong indicators of the health of the environment. Studies show that these creatures provide essential functions when it comes to food, soil and wetland ecology as well as recycling systems of forests. Important medical science contributions and life-saving drugs come from amphibians and reptiles as well.
