Reptiles are a diverse group of vertebrates and consequently what reptiles eat differs from species to species. That said, there are some general dietary trends in reptiles that can be noted. Most reptiles are carnivores that feed on small invertebrates, mammals and reptiles. A few reptiles are herbivores that feed on plant material as varied as grasses, fruits, shrubs and marine plants such as algae and kelp.
Dietary trends can also be observed within each of the four subgroups of reptiles (crocodilians, squamates, tuataras and turtles). The diets of each reptile subgroup is discussed in more detail below.
What do crocodilians eat?
Crocodilians are semi-aquatic carnivores that includes crocodiles, alligators, caimen and gharials. Crocodiles, alligators and caimen feed on a variety of small vertebrate prey including birds, small mammals and fish. They also eat the carcases of dead animals. Gharials have long very narrow snouts well suited for snapping prey quickly underwater. They feed primarily on fish.
What do turtles eat?
Most adult turtles are herbivores that feed on grass, leaves, shrubs, fruit; some turtles eat small insects such as caterpillars and grubs that get caught up in the plant material the feed on; most young freshwater turtles eat the larvae of aquatic invertebrates; sea turtles have different diets from species to species, some sea turtle species eat jellyfish and shellfish, while others feed primarily on seagrass and algae.
What do squamates eat?
Squamates are the most numerous of all reptile groups and include snakes, lizards and amphisbaenians. Most squamates are carnivores that feed on small animal prey.
Most lizards are predators that feed primarily on small insects and other terrestrial invertebrates. Larger lizards also eat small vertebrates such as birds, mammals and reptiles. The largest of all lizards, the Komodo dragon is both a predator and a scavenger and feeds on large animals that it kills or carcasses it encounters. Komodo dragons have been know to eat prey as large as water buffaloes. A small number of lizards are hebivores. The marine iguana of the Galapagos Islands, for example, feeds on marine plants such as kelp and algae. Many iguanas eat plant material.
All snakes are carnivores. They feed on a wide variety of prey such as invertebrates, frogs, toads, lizards, birds' eggs and mammals. Since snakes cannot dismember their prey as they have no limbs to help them tackle such a task, they must swallow prey whole.
Amphisbaenians, also known as worm lizards, are burrowing squamates that live their life below ground. Like most other squamates, they too are predators. They have a crushing bite which they use to subdue their prey: arthropods, worms or small vertebrates
What do tuataras eat?
Tuataras, a rare group of reptiles that inhabit a few rocky islands off the coast of New Zealand, feed on small invertebrates such as beetles, crickets and spiders. The also eat frogs, lizards and the eggs and chicks of seabirds occasionally.
Summary of what reptiles eat
Most reptiles are predators which means they eat other animals to survive. But many reptiles are not very large so they limit their prey to animals that are smaller than they are such as invertebrates, amphibians, small mammals and small reptiles. There are a few reptiles though that are herbivores and feed mostly on plant material. Sea turtles, terrestrial turtles, some land iguanas and marine iguanas are examples of plant-eating reptiles.