Animals of the World

The variety of animal life is organized by scientists into a system of groups based on shared features and common ancestry. At the broadest level animals are split into vertebrates, with a backbone, and invertebrates, without one. Within the vertebrates, reptiles such as iguanas and other lizards form a group of cold-blooded animals with scaly skin, while mammals such as the big cats and wild dogs are warm-blooded and usually bear live young.

Reptiles display a wide range of forms and habits. Lizards like the iguana are mostly plant-eaters that bask in the sun to warm their bodies, while many snakes are hunters that subdue prey by venom or constriction. Mammalian predators, by contrast, rely on speed, teeth, and claws; the jaguar is a powerful big cat of the Americas, and jackals are adaptable wild relatives of the dog that often scavenge as well as hunt.

Beyond these groups, the animal kingdom includes birds, amphibians, fish, and the enormous number of invertebrates such as insects and arachnids. Each occupies a place in its ecosystem, and the interactions among them maintain a balance that can be disrupted when habitats change. Conservation programs and protected reserves aim to keep endangered species from disappearing.

Frequently asked questions

What kind of animal is an iguana?

An iguana is a large lizard, a cold-blooded reptile with scaly skin. Many iguanas are mainly plant-eaters that bask in the sun to warm up.

Where do jaguars live?

The jaguar is a large cat native to the Americas, especially forested regions of Central and South America, where it is a top predator.

Are jackals related to dogs?

Yes. Jackals belong to the dog family and are adaptable animals that both hunt small prey and scavenge for food.