Endothermic vertebrate with hair Warm-blooded Permits high level of activity at night and year-...

MAMMALS

Endothermic vertebrate with hairWarm-bloodedPermits high level of activity at night and

year-round (regardless of outside temperature)

Females have mammary glands Function: make/secrete milk for young

About 5000 species Ex: cats, dogs, humans, dolphins,

elephants, kangaroo, whale, bat, rabbit, beaver, wolf, seal, mouse, platypus, chimpanzee, tiger

GENERAL CHARACTERISTICS

High degree of parental care Body covered by hair

In some, hair is reduced in size – like humans

All have an integument (external covering) Contains: sweat, scent, sebaceous and

mammary glands

GENERAL CHARACTERISTICS

Breathe using lungs Excrete using kidneys Separate sexes Young nourished by milk (made by

the mammary glands) Many have territories

These are areas from which individuals of the same species will reside

Will often resort to violence to protect these territories

GENERAL CHARACTERISTICS

Rodents Ex: mice, squirrels, rats, woodchucksHave two razor sharp incisors for

gnawing Lagomorpha

Ex: rabbits, hares, pikasAll are herbivores

Hominids Ex: humans, gorilla, orangutan, chimps

Insectivora Ex: moles, shrewsDiet consists of insects

CLASSIFICATION

Carnivora Ex: weasels, seals, walruses, dogs,

wolves, cats, bearsHighly predatory animals, Contain teeth for tearing flesh

Proboscidea Ex: elephantsLargest of living land animals

CLASSIFICATION

Perissodactyla Ex: horses, donkeys, zebras, rhinosOften referred to as ungulates or the

hoofed animals Cetacea

Ex: dolphins, whales, porpoisesLimbs are modified into flippersLive in aquatic environments only

CLASSIFICATION

Skeleton Skeletal/bone make-up allows for:

High-speed running Swimming climbing trees Movement of digits (fingers/toes) to help

grasp objectsJoints allow for a greater range of

motion

MOVEMENT AND RESPONSE

Hair:Has become a modified sense

“organ”Purpose of hair:

Spines of porcupines—protectionHair of most animals—insulationVibrissae (whiskers)—provide

tactile sense Slightest movement indicates minimal

space available (cat/dog)

MOVEMENT AND RESPONSE

Moveable eyelids Fleshy external ears Well-developed brain

The largest brain in animal kingdomCerebrum—processes info for thinking

and learningHigh evolved brain allows for highly

developed memory and capacity to learn topics/developmental milestones quicker

MOVEMENT AND RESPONSE

Highly elaborate sensory organsProvide mammals with a high level of

environmental awareness and responsiveness

Senses: taste, smell, hearing, sightMost have great eyesight Many can’t see colorMany will use echolocation to

communicate and/or navigate Ex: Bats, dolphins

MOVEMENT AND RESPONSE

TeethMammalian teeth are both more

complicated and more efficient than in other vertebrates

Mammals are heterodonts (some of our teeth are different)

Specialized for variety of functions: Includes: grind, stab, scissor, dig, chisel,

sieve and lift (elephants tusks)

DIGESTION AND EATING

Teeth, cont.Teeth in mammals come in four different

sorts: Incisors, Canines, Premolars and Molars. Not all mammals have all

Use this variety to eat a wide variety of food

Most placental mammals have between 20 and 40 teeth, while most marsupials have 30 to 50.

As a general rule animals that feed on insects have more teeth than either herbivores or the larger carnivores.

DIGESTION AND EATING

Contain a secondary palateSeparates air passageway from the

food passageway Allows mammals to hold (and

partially break down food) in mouths without interrupting breathing

DIGESTION AND EATING

Have many feeding adaptations Insectivores are often smallHerbivores have two groups

Groups: browsers and grazers Have large molars adapted for grinding

Carnivores have large canines Adapted for ripping/tearing meat

Other adaptations:Ruminants (cattle, bison, goats) have a

four-chambered stomach

DIGESTION AND EATING

Energy and WastesRequire much energy to keep a

constant body tempProduce a variety of waste products

(uric acid, urine, feces, etc) Digestive tract

If mammals eats only plants, longer digestive tract Why? takes longer to digest

plants/celluloseIf eat only meat, shorter digestive tract

DIGESTION AND EATING

Require a large amount of oxygen for respiration

2 organ adaptations for this:Diaphragm:

Muscle that contracts and therefore, allows for more rapid/controlled breathing

Four-chambered heart: Separates blood into

oxygen-rich/oxygen-poor

RESPIRATION

All have internal fertilization All have mammary glands 3 groups of Mammal life cycles:

1. Placental:2. Marsupials:3. Monotremes:

LIFE CYCLE

Placental:Develop inside mother’s body 95% of mammals are thisPlacenta—organ which allows for

nutrients, oxygen, carbon dioxide and wastes to be exchanged

LIFE CYCLE

Placental, cont.:Gestation period—time that

embryo stays in the mother’s body Humans: 9 months, Elephants:

27 months, Mice: 21 daysMammary gland—young continue

to feed by sucklingEx: humans, dolphin, elephant,

most mammals

LIFE CYCLE

Marsupials:Give birth to small, immature young that

develop in a mother’s external sac (kangaroo)

Mothers can move around and look for food while baby develops in the pouch

Ex: kangaroo, koala, panda Monotremes:

Mammals that give birth by laying eggs Incubate using her heatEx: platypus

LIFE CYCLE