Birds & Mammals - PowerPoint Presentation

Slide1

Birds & Mammals

Chapter 16Slide2

Birds

Birds belong to the class Aves.

Aves comes from the Latin word for bird

.First appeared on Earth 150 million years ago

Section 1Slide3

Bird Characteristics

S

hare some characteristics with reptiles

Thought to be descendent from dinosaursLegs & feet covered by thick, dry scalesThe skin around their beaks

scaly

Have amniotic eggs – with an amniotic sac & a shell

but bird shells are generally harder than reptiles which are usually leatheryBeaks instead of teeth & jawsHave feathers, wings, & many other adaptations for flight

Section 1Slide4

Bird Characteristics: Cont.

Birds of a Feather

Two kinds of feathers

Down Feathers = fluffy, insulating feathers that lie next to a bird’s body.

Contour Feathers

= cover the body & wings of birds to form a streamlined flying surfacePreening = a process where birds use their beaks to spread oil on their feathers (The oil helps make the feathers water repellent & keeps them clean)Section 1Slide5

Bird Characteristics: Cont.

High-Energy Animals

Birds are endothermic – they maintain a constant body temperature

Have a high metabolism which generates a lot of body heatAverage body heat of bird is 40

o

C higher than a humans

Birds can’t sweat if they get too hot so they pant like dogs do.Section 1Slide6

Bird Characteristics: Cont.

Eat Like a Bird?

Most birds eat a high-protein, high-fat diet of insects, nuts, seeds, leaves, or meat.

D

on’t have teeth, so they can’t chew their food.

F

ood goes directly from the mouth to the crop, where it is stored. Birds also have an organ called a gizzard, which often contains small stones. The stones in the gizzard grind up the food so that it can be easily digested by the intestine.

Section 1Slide7

Up, Up, & Away

Birds have a long list of adaptations for flight even those that are flightless.

Most birds have large eyes & excellent eyesight.

This allows them to see objects & food from a distance. The heart

of a bird beats rapidly.

This ensures that the flight muscles get as much oxygen as the blood can carry.

Section 1Slide8

Up, Up, & Away: Cont.

Birds have special organs called

air sacs

attached to their lungs.The air sacs increase the amount of oxygen that a bird can take in & allow air to flow constantly in one direction through the lungs.

The shape of a bird’s wings is related to the kind of flying it does.

Short, rounded wings allow rapid maneuvers. Long narrow wings are best for soaring.

Section 1Slide9

Up, Up, & Away: Cont.

Bird skeletons are compact & strong.

Some of the vertebrae, ribs, & hip bones are fused together. This makes the skeleton of birds more rigid than that of other vertebrates.

Bone is a heavy material, but birds have much lighter skeletons than those of other vertebrates because their bones are hollow.But bird bones are still very strong because they have thin cross-supports that provide strength, much like the trusses of a bridge do.

Section 1Slide10

Up, Up, & Away: Cont.

Birds that fly have powerful flight muscles attached to a large breastbone called a

keel

. These muscles move the wings.All of the previous adaptations make a bird well suited for flight, but how do birds actually overcome gravity & get into the air?

Section 1Slide11

Getting Off the Ground

Lift

= the upward pressure on the wing that keeps a bird in the air.

The air on top has to move farther than the air underneath. As a result, the air on top moves faster

than the air underneath. The faster moving air on top creates low pressure in the air. This is called

Bernoulli effect

. The air pressure under the wing is higher & pushes the wing up.Birds generate extra lift by flapping their wings. Another factor that affects lift is wing size. Section 1Slide12

Fly Away

Birds have

good reasons to

migrate & are able to migrate great distances.They can find better territories with more food. G

reat places for birds to raise their young.

Section 1Slide13

Bring Up Baby

Birds reproduce by internal fertilization & by laying amniotic eggs with the developing embryo inside just like reptiles.

But they must keep their eggs warm for the embryo to develop.

Brooding = birds sit on their eggs until the eggs hatch, using their body heat to keep the eggs warm

Section 1Slide14

Bring Up Baby: Cont.

Ready to Go

Precocial

= birds that hatch fully activeCovered with downy feathers when born

F

ollow their parents as soon as they can stand up

Depend on their mother for warmth & protectionCan walk, swim, & feed themselvesSection 1Slide15

Bring Up Baby: Cont.

Help Wanted

Altrical

= birds hatch weak, naked, & helplessEyes are closed when they are born

Cannot walk or fly

Parents must keep them warm & feed them for several weeks.

When the chicks grow their first flight feathers they begin to learn to flyOften end up walking around on the ground. The parents must work feverishly to distract predators & protect their youngSection 1Slide16

Kinds of Birds

There are almost 9,000 species of birds on the Earth, because of the diversity they are divided into 29 different orders.

This can be confusing so they are usually divided into four nonscientific categories: flightless birds, water birds, birds of prey, & perching birds.

Not all birds are included in these categories but they dhow how different birds can be

Section 1Slide17

Kinds of Birds: Cont.

Flightless Birds

– ostriches, kiwis, emus, ostriches, & other flightless birds do not have a large keel for flight. Though they cannot fly, many flightless birds are fast runners.

Water Birds – sometimes called

waterfowl

. These include cranes, ducks, geese, swans, pelicans, loons, & other species. These birds usually have webbed feet for swimming, but they are also strong flyers.

Section 1Slide18

Kinds of Birds: Cont.

Birds of Prey

– eagles, hawks, falcons, & other birds of prey are meat eaters

. The sharp claws on their feet & their sharp, curved beaks help these birds catch & eat their prey. They also have very good vision. Most birds of prey hunt during the day.

Perching Birds

– songbirds, like robins, wrens, warblers, & sparrows, are perching birds. These birds have special adaptations for perching on a branch. When a perching bird lands on a branch, its feet automatically close around the branch. So even if the bird falls asleep, it will not fall off.

Section 1Slide19

Birds Review

List three ways birds are similar to reptiles & three ways they are different

Explain the difference between precocial chicks & altricial chicks

Name some of the adaptations that make bird bodies lightweight.Would an airplane wing that is not curved on top generate lift?

How did perching birds get their name?

Birds of prey have extremely good eyesight. Why is good vision important for these birds

?Section 1Slide20

Mammals

4,500 species of mammals

Live in the coldest oceans to the hottest desert & every climate in between

The origin of MammalsTherapsides

= the early ancestor of mammals (they lived about 280 million years ago)

200 million years ago mammals were about the size of mice, because they were endotherms they could hunt at night & avoid their dinosaur predators.

Section 2Slide21

Characteristics of Mammals

Mamma!

All mammals have

mammary glands. Mammary Glands = secrete a nutritious fluid called milk.

O

nly

mature female mammals make milk, male mammals have small inactive mammary glandsFemale mammals usually bear live young & care for their offspringAll milk is made of water, protein, fat, & sugar.

Section 2Slide22

Characteristics of Mammals: Cont.

Cozy & Warm

All mammals are endotherms

Body temperature kept constant except when hibernating, estivating, or running a fever.Staying Warm

All mammals have hair somewhere on their body.

Most mammals have a layer of fat under their skin that acts as insulation.

Section 2Slide23

Characteristics of Mammals: Cont.

Crunch!

Have specialized teeth

Canines – stabbing teeth, shaped like spears

Incisors

– cutting teeth, in front of your mouth

Molars – flat teeth, that help grind up foodThe kinds of teeth a mammal have reflect its dietHave two sets of teethMilk teeth – a mammal’s first set of teeth

Permanent adult teeth – begins eating solid food & its jaw grows larger

Section 2Slide24

Characteristics of Mammals: Cont.

Getting Oxygen

Mammals need oxygen to efficiently break down the food they eat.

Mammals use lungs to get oxygen from the airDiaphragm

= a large muscle that lies at the bottom of the rib cage which helps bring air into the lungs.

Have a four chambered heart – keeps blood with oxygen separate from blood without oxygen.Section 2Slide25

Characteristics of Mammals: Cont.

Large Brains

Allows them to learn, move, & think quickly

Keep track of what is going on & to respond quicklyMost coordinated of all animals

Depend on five major senses to gather information about their environment: vision, hearing, smell, touch, & taste.

The importance of each sense for any give mammal depends on the mammals environment

Section 2Slide26

Characteristics of Mammals: Cont.

Mammal Parents

Reproduce by internal fertilization

Most mammals give birth to live youngAll mammals nurse their young

Born helpless & they require a lot of care

Mammal parents are very protective, with one or both parents caring for their young until they are grown.

Section 2Slide27

Kinds of Mammals

Mammals are divided into three groups based on the way their young develop

Monotremes

Monotremes = mammals that lay eggsOnly found in Australia & New Guinea

Only three species today: two are echidnas, the third is the duckbilled platypus

Lays one or two eggs with thick, leathery shells

Keep eggs warm like birds doCan’t nurse like other mammals, no nipple, instead the kind of sweat out the milk

Section 2Slide28

Kinds of Mammals: Cont.

Marsupials

Marsupials

= mammals with pouchesGive birth to live young that are not fully developed, they then travel to the pouch where they continue to develop, there are mammary glands in the pouch.

280 species which include opossum, koalas, Tasmanian devils, & wallabies

Found in Australia, New Guinea, & South America

Section 2Slide29

Kinds of Mammals: Cont.

Placental Mammals

Most mammals are placental mammals

Placental Mammals

= embryos stay inside the mother’s body & develop in a

uterus

Placenta = a special attachment from the embryo to the uterus of their mother. It supplies food & oxygen from the mother’s blood to the growing embryo & it removes wastes from the embryoGestation period = the time during which an embryo develops within the mother

Section 2Slide30

Kinds of Placental Mammals

90% or all mammals on Earth are placental mammals

They are classified into 18 orders

Toothless Mammals – anteaters, armadillos, aardvarks, pangolins, & sloths

Although

these mammals are called “toothless,” only the anteaters are completely toothless. The others have small teeth. Most toothless mammals feed on insects they catch with their long sticky tongues.

Section 2Slide31

Kinds of Placental Mammals: Cont.

Insect

Eaters –

moles, shrews, & hedgehogs.Insect eaters, or insectivores, live on every continent except Australia. Most insectivores are small, & most have long pointed noses to dig into the soil for food. Compared with other mammals, they have a very small brain & few specialized teeth.

The first mammals on Earth looked much like today’s insectivores

.

Section 2Slide32

Kinds of Placental Mammals: Cont.

Rodents –

squirrels, mice, rats, guides pigs, porcupines, &

chinchillasMore than one-third of all mammalian species are rodents, & they can be found on every continent except Antarctica.

Most

rodents are small animals with long, sensitive whiskers. Rodents are chewers & gnawers. All rodents have sharp front teeth for gnawing. Because rodents chew so much, their teeth wear down. So a rodent’s incisors grow continuously, just like your fingernails do.

Section 2Slide33

Kinds of Placental Mammals: Cont.

Lagomorphs –

Rabbits, hares, & pikas

Like rodents, they have sharp gnawing teeth. But unlike rodents, they have two sets of incisors in their upper jaw & short tails. Rabbits & hares have long, powerful hind legs for jumping. To detect their many predators, they have sensitive nose & large ears & eyes.

Section 2Slide34

Kinds of Placental Mammals: Cont.

Flying

Mammals –

Bats are the only mammals that can flyThese

mammals have wings made of long finger bones connected by webs of skin. Bats are active at night & sleep in sheltered areas during the day. When they rest, they hang upside down. Most bats eat insects. But some bats eat fruit, & three species of vampire bats drink the blood of other animals. The largest bats are the fruit bats, with a mass of up to 1 kg & wingspans up to 2 m. But most bats have a mass of only a few grams.

Section 2Slide35

Kinds of Placental Mammals: Cont.

Carnivores –

“meat eater”

– lions, wolves, weasels, otters, bears, raccoons, & hyenas

Carnivores are a group of mammals that have large canines & special teeth for slicing meat.

Carnivores

also include a group of fish-eating marine mammals called pinnipeds. The pinnipeds include seals, sea lions, & walruses. Some carnivores also eat plants. For example, black bears eat grass, nuts & berries & only rarely eat meat. But many carnivores eat nothing but other animals.

Section 2Slide36

Kinds of Placental Mammals: Cont.

Hoofed

Mammals –

horses, zebras,

pigs, cows, deer, hippopotamuses, & giraffes

Most hoofed mammals are adapted for swift running. Because they are plant eaters, they have large, flat molars to help them grind plant material. Some also have modified digestive system that can handle large amounts of cellulose. Hoofed mammals are divided into groups based on the number of toes they have. Odd-toed hoofed mammals have one or three toes. Even-toed hoofed mammals have two or four toes.

Section 2Slide37

Kinds of Placental Mammals: Cont.

Trunk-Nosed

Mammals –

Elephants are the only mammals with a trunk

The

trunk is an elongated & muscular combination of the upper lip & nose. Elephants use their trunk the same way we use our hands, lips, & nose. The trunk is powerful enough to lift a tree yet agile enough to pick small fruits one at a time. Elephants use their trunks to place food in their mouth & to spray their back with water to cool off

.Elephants are the largest land animals. Section 2Slide38

Kinds of Placental Mammals: Cont.

Cetaceans

–

Whales, dolphins, & porpoises make up a group of water-dwelling mammals.At first glance whales & their relatives may look more like fish than mammals. But like all mammals, cetaceans are endotherms, they have lungs, & they nurse their young. Most of the largest wales are toothless whales that strain tiny, shrimplike animals form sea water. But dolphins, porpoises, sperm whales, & killer whales have teeth, which they use to eat fish & other animals.

Section 2Slide39

Kinds of Placental Mammals: Cont.

Sirenia

– three kinds of manatees & the dugong

The smallest group of water-dwelling mammals. These mammals are completely aquatic; they live along coasts & in large rivers. They are quiet animals that eat seaweed & water plants.

Section 2Slide40

Kinds of Placental Mammals: Cont.

Primates

– prosimians, monkeys, apes, & humans

There are about 160 species of primates. All primates have the eyes facing forward, enabling both eyes to focus on a single point. Most have five fingers on each hand & five toes on each foot, with flat fingernails instead of claws. Their fingers & opposable thumbs are able to make complicated movements, like grasping objects. They have a large brain in proportion to their body size & are considered some of the most intelligent mammals.

Section 2Slide41

Mammals Review

Name three characteristics that are unique to mammals

What is the purpose of a diaphragm?

Suppose you found a mammal skull on an archaeological dig. How would the teeth give you clues about the mammal’s diet?

How are

monotremes

different form all other mammals? How are the similar?Section 2