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Finding Foods

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Mammals use many different strategies to find food. Some mammals are hunters, while others are scavengers and dine on leftovers. some migrate in search of food and others hoard food for winter. Mammals eat almost anything, from plants to other mammals. Vampire bats live on blood, echidnas eat ants and a pack of wolves will eat a moose or other large mammal. The amount of food a mammal eats varies greatly. Very small mammals cannot store much energy and warmth inside their bodies. Because they lose energy quickly, they have to eat a lot of food. A shrew, for example, must eat more than its own body weight every day or it will freeze to death. Strangely enough, the largest mammal-the whale-also eats large amounts of food. This is because it grows quickly (a newborn blue whale gains about 200 lb [90 kg] every day!) and because it has to swim long distances in search of food.  Desert Dining  - Gerenuks feeding on the leaves of prickly bushes -  The gerenuk, ...
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Mammal Beginnings

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The first mammals were small, shrewlike animals that were about 5 inches (12 cm) long. Related to today's monotremes, they first appeared during the Triassic Period, about 220 million years ago. They were descended from reptiles called synapsids , which appeared about 300 million years ago. These primitive mammals evolved into different groups during the Jurassic and Cretaceous periods (208-65 million years ago). Most of these early mammals were carnivores (meat eaters), but some, such as the tree-living multituberculates, which ranged from animals the size of mice to some as big as beavers, ate plants. The ancestors of today's marsupials, insectivores and primates first appeared in the Cretaceous Period (145-65 million years ago). When the dinosaurs died out at the end of the Cretaceous Period, these modern mammals spread to every continent and evolved into thousands of new species. The First Mammal - Megazostrodon - Megazostrodon, which lived in Africa abou...
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Designs for Living

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Mammals are among the most successful animals ever to have lived. Because they are warm-blooded, they can survive in almost any environment. To take advantage of different environments,, mammals have evolved different body shapes. They have adapted to life in the jungles, deserts and high mountains; in the polar regions; in the air and in the trees; beneath the ground and in the oceans. They have also adapted as they moved from one environment to another. The ancestors of today's horses, for example, lived in forests and were small enough to move among trees and undergrowth. When they began to live on the open plains. however, they grew larger and stronger so they could migrate in search of fresh food, and faster so they could escape the fast-moving predators of the plains. Looking alike  Some mammals look similar and live in similar ways even though they are not related to each other and live in different parts of the world. Scientists call this "Convergent evolution...
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Introducing Mammals!

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Most of the animals we keep as pets, such as dogs, cats, and rabbits, and the animals we use for work, such as horses, are mammals. Humans are mammals too. Mammals belong to a group of animals called vertebrates , all of which have backbones. They are warm-blooded, which means they have a constant body temperature, no matter how cold or hot their surroundings may be. There are nearly 4,000 species of mammal, and most of these have hair or fur on their bodies. Except for the platypus and echidna, all mammals give birth to live young. Unlike other animals, they feed their young with milk. Mammals Evolved from reptiles that had several bones in the lower jaw.  Types of Mammals The three main groups of mammal are; monotremes marsupials placental mammals Monotremes (the platypus and echidna) have many features in common with mammals' reptile ancestors. They have a single opening, called a cloaca , for reproduction and body wastes, and they lay eggs.  Female ...
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