Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Birds and Mammals Table of Contents Section 1 Characteristics of Birds Section 2 Kinds of Birds Section 3 Characteristics of Mammals Section 4 Placental Mammals Section 5 Monotremes and Marsupials Chapter 17

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Objectives Describe two kinds of feathers. Describe how a bird’s diet, breathing, muscles, and skeleton help it fly. Explain how lift works. Describe how birds raise their young. Chapter 17 Section 1 Characteristics of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Characteristics of Birds Birds share many characteristics with reptiles such as being vertebrates, having scales on parts of their bodies, and laying amniotic eggs with shells. Birds have unique characteristics such as laying eggs with hard shells, and having feathers, wings, and a beak. Birds can also maintain a constant body temperature. Chapter 17 Section 1 Characteristics of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Feathers Feathers help birds stay dry and warm, attract mates, and fly. Preening and Molting Birds take good care of their feathers. They use their beaks to * Molting is the process of *. Chapter 17 Section 1 Characteristics of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Feathers, continued Two Kinds of Feathers Fluffy feathers that lie next to a bird’s body are called * Contour feathers are stiff feathers that cover a bird’s body and wings. Contour feathers help some birds attract mates and fly. Chapter 17 Section 1 Characteristics of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 17 Section 1 Characteristics of Birds The Structure of a Contour Feather

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu High-Energy Animals Fast Metabolisms Birds need a lot of energy to fly. To get this energy, their bodies break down food quickly. Chapter 17 Section 1 Characteristics of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Fast Digestion High-Energy Foods Because birds need a lot of energy, they eat a lot. Most birds eat * Birds have a unique digestive system to help them get energy quickly. Chapter 17 Section 1 Characteristics of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 17 Section 1 Characteristics of Birds The Digestive System of a Bird

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Flying Most birds can fly. Even flightless birds, such as ostriches, have ancestors that could fly. Birds have many adaptations for flight. In addition to wings, birds * Chapter 17 Section 1 Characteristics of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 17 Section 1 Characteristics of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 17 Section 1 Characteristics of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Getting Off the Ground Birds need to overcome gravity to fly. Flapping their wings help birds get up into the air and to push forward through the air. A bird’s wings create lift. Lift is * The shape of the wing affects the air around it. As air flows over and under a bird’s wings, the air’s speed and direction change. This change causes lift. Chapter 17 Section 1 Characteristics of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 17 Section 1 Characteristics of Birds Lift Keeps Birds in the Air

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Raising Baby Birds Like reptiles, birds reproduce sexually by internal fertilization. Birds also lay amniotic eggs. Unlike most reptiles, birds must keep their eggs warm for the embryos to live and grow. Nests Many birds build nests in which they lay their eggs. * is called brooding. Chapter 17 Section 1 Characteristics of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Raising Baby Birds, continued Precocial and Altricial * are called precocial. Precocial chicks, such as chicken and duck chicks, can walk, swim and feed themselves shortly after birth. The mother provides warmth and protection. Altrical chicks, such as hawk and songbird chicks, are born *. Chapter 17 Section 1 Characteristics of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Objectives Identify the differences between flightless birds, water birds, perching birds, and birds of prey. Chapter 17 Section 2 Kinds of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Kinds of Birds Scientist group living birds into 28 different orders. Songbirds make up the largest order. Birds are often grouped into four nonscientific categories: * These categories do not include all birds, but they do show how different birds can be. Chapter 17 Section 2 Kinds of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Flightless Birds Running and Swimming Not all birds fly. Most flightless birds do not have the large keel that anchors birds’ flight muscles. Instead of flying, some flightless birds run quickly to move around. Others are skilled swimmers. Chapter 17 Section 2 Kinds of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Water Birds Many flying birds are also comfortable in the water. These water birds include cranes, ducks, geese, swans, pelicans, and loons. These birds usually have webbed feet for swimming or long legs for wading. Some water birds have a rounded, flat beak for eating plants or small invertebrates. Others have a long, sharp beak for catching fish. Chapter 17 Section 2 Kinds of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Perching Birds Perching birds have special adaptations for resting on branches. Songbirds, such as robins, warblers, and sparrows, make up a large part of this group of birds. When a perching bird lands in a tree, its feet *. Chapter 17 Section 2 Kinds of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Birds of Prey Birds of prey hunt and eat other vertebrates. These birds may eat insects or other invertebrates in addition to mammals, fish, reptiles, and birds. Birds of prey have *. Chapter 17 Section 2 Kinds of Birds

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Objectives Explain how early mammals lived. Describe seven common characteristics of mammals. Chapter 17 Section 3 Characteristics of Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu The First Mammals Fossil evidence indicates that about 280 million years ago, reptiles called therapsids existed. These animals had * True mammals appeared appeared in the fossil record more than 225 million years ago. They were about the size of mice. Since they were endotherms, early mammals could feed at night and avoid dinosaurs. After dinosaurs became extinct, mammals started to spread out and live in different environments. Chapter 17 Section 3 Characteristics of Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Common Characteristics Making Milk * are called Mammary glands. Breathing Air Mammals have a muscle that helps them get air. The diaphragm is a * Endothermic Mammals are endotherms. The ability to stay warm helps them survive in cold areas and stay active when the weather is cool. Chapter 17 Section 3 Characteristics of Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Common Characteristics, continued Hair All mammals—even whales—have hair. Mammals that live in cold climates usually have thick coats of hair. These thick coats are called fur. Most mammals have a layer of fat under their skin to keep warm. Blubber is * Chapter 17 Section 3 Characteristics of Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Common Characteristics, continued Specialized Teeth Another unique mammal characteristic is specialized teeth. Fish and reptiles have teeth, but usually they are all identical. Mammals have incisors, canines, and molars. Incisors are located * Next to the incisors are the canines, which help * In the back of the mouth are the molars, which help * Chapter 17 Section 3 Characteristics of Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Common Characteristics, continued Sexual Reproduction All mammals reproduce sexually. Though there are a few exceptions, most mammals give birth to live young. Newborn mammals stay with at least one parent until they are grown. Large Brains A mammal’s brain is much larger than that of most other animals that are the same size. This large brain allows mammals to learn and think quickly. Chapter 17 Section 3 Characteristics of Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Objectives Explain how placental mammals develop. Give an example of each type of placental mammal. Chapter 17 Section 4 Placental Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Placental Mammals Mammals are divided into groups based on how they develop. A placental mammal is a mammal whose * * called the gestation period. Chapter 17 Section 4 Placental Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Anteaters, Armadillos, and Sloths A few mammals have unique backbones that have special connections between the vertebrae. This group includes anteaters, armadillos, and sloths. Most mammals in this group eat insects they catch with their long, sticky tounges. Chapter 17 Section 4 Placental Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insectivores Mammals that eat insects are known as insectivores. This group includes moles, shrews, and hedgehogs. Most members of this group are small, have long, pointed noses, small brains, and simple teeth. Chapter 17 Section 4 Placental Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Rodents More than one-third of mammal species are rodents. Rodents live on every continent except Antarctica. Squirrels, mice, rats, guinea pigs, porcupines, and chinchillas are all rodents. Rodents have one set of incisors in their upper jaw. Rodents gnaw and chew so much that their teeth wear down. But that doesn’t stop their chewing––their incisors grow continuously! Chapter 17 Section 4 Placental Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Rabbits, Hares, and Pikas Rodents are similar to a group of mammals that includes rabbits, hares, and pikas. Like rodents, they have sharp gnawing teeth. Unlike rodents, this group has two sets of sharp incisors in their upper jaw. Their tails are also shorter than rodent’s tails. Chapter 17 Section 4 Placental Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Flying Mammals Bats are the only mammals that fly. Bats are active at night. They sleep in protected areas during the day. Most bats eat insects or other small animals. But some bats eat fruit or plant nectar. * is called echolocation. Chapter 17 Section 4 Placental Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Carnivores Mammals that have large canine teeth and special molar teeth for slicing meat are called carnivores. Many mammals in this group eat only meat, but other members of this group are omnivores or herbivores that eat plants. Bears, cats, dogs, otters, raccoons and pinnipeds––*– –are all carnivores. Chapter 17 Section 4 Placental Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Trunk-Nosed Mammals Elephants are the only mammals that have a trunk. The trunk is a combination of an upper lip and a nose. An elephant uses its trunk in the same ways we use our hands, lips, and nose. Elephants use their trunks to put food in their mouths and to spray water on their backs to cool off. Chapter 17 Section 4 Placental Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Hoofed Mammals Horses, pigs, deer, and rhinoceroses are some of the many mammals that have thick hoofs. A hoof is a thick, hard pad that covers a mammal’s toe. The hoof is similar to a toenail or a claw, but it covers the entire toe. Hoofed mammals are divided into two orders ––* Chapter 17 Section 4 Placental Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Cetaceans Cetaceans are a group of mammals made up of whales, dolphins, and porpoises. All cetaceans live in the water. While they may look like fish, cetaceans have lungs and nurse their young. Like bats, cetaceans use echolocation to find fish and other animals. Chapter 17 Section 4 Placental Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Manatees and Dugongs The smallest group of mammals that live in the water are manatees and dugongs. This group includes three species of manatees and the dugong. Manatees and dugongs use their front flippers and a tail to swim slowly through the water. They live along coasts and rivers where they eat seaweed and water plants. Like cetaceans, manatees and dugongs surface to breathe air. Chapter 17 Section 4 Placental Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Primates Scientists classify prosimians, monkeys, apes, and humans as primates. These animals have * Primates have a larger brain than most other mammals the same size have. They are considered highly intelligent animals. Chapter 17 Section 4 Placental Mammals

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Objectives Describe the difference between monotremes and marsupials. Name the two kinds of monotremes. Give three examples of marsupials. Explain why many marsupials are endangered or extinct. Chapter 17 Section 5 Monotremes and Marsupials

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Monotremes A monotreme is * A female monotreme lays eggs with thick, leathery shells. She uses her body energy to keep the eggs warm. Monoterms do not have nipples. Their young lick milk from the skin and hair around the mother’s mammory glands. Chapter 17 Section 5 Monotremes and Marsupials

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Monotremes, continued Echidnas Of the two living species of monotremes, two are echidnas. Their large claws and long snouts help them dig ants and termites out of insect nests. The Platypus The other other living monotreme species is the platypus that lives in Australia. Platypuses are swimming mammals that feed and live in rivers and ponds. They us their webbed feet and flat tails to move through the water. Their flat, rubbery bill is used to dig for food and dig tunnels in riverbanks. Chapter 17 Section 5 Monotremes and Marsupials

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Marsupials, continued * is a marsupial. Like all mammals, marsupials have mammary glands, hair, and specialized teeth. They give birth to live young. Marsupials development is unique because newborn marsupials continue their development in a mother’s pouch. Chapter 17 Section 5 Monotremes and Marsupials

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Marsupials, continued The Pouch Marsupials are born at an early stage of development. They are born just days or weeks after fertilization. Newborns drag themselves through their mother’s fur to the pouch on her belly where they continue to develop. Inside the pouch, the newborn latches onto a nipple, and starts drinking milk. Young kangaroos, called joeys, stay in the mother’s pouch for several months. Chapter 17 Section 5 Monotremes and Marsupials

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Marsupials, continued Kinds of Marsupials Familiar marsupials include kangaroos, opossums, and koalas. Most marsupials live in and around Australia. Chapter 17 Section 5 Monotremes and Marsupials

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Marsupials, continued Endangered and Extinct Marsupials The number of living marsupial species is decreasing. Several species of marsupials have gone extinct in Australia, and many more species are in danger. When Europeans came to Australia they brought exotic species such as rabbits, cats, and foxes. These exotic animals * * Chapter 17 Section 5 Monotremes and Marsupials