SCIENCE 7 TOPIC 13

WARM-BLOODED VERTEBATES INCLUDES THE BIRDS AND…

…WARM-BLOODED VERTEBRATES ALSO INCLUDES THE MAMMALS

Warm-blooded vertebrates maintain a constant body temperature

Warm-blooded vertebrates have very complex body systems such as…

…and digestive system to name just two

THE MAIN BIRD TRAIT IS FEATHERS

CONTOUR FEATHERS

THE MAIN BIRD TRAIT IS FEATHERS DOWN FEATHERS CONTOUR FEATHERS

WHY ARE BIRDS CAPABLE OF FLIGHT?

Lightweight but strong skeletal structure

Air sacs

Crop

Complex 4-chambered heart

Streamlined shape

WHY DO BIRDS MIGRATE?

WHY DO BIRDS MIGRATE? Too cold and/or …

WHY DO BIRDS MIGRATE? Too cold and/or the food supply becomes scarce

HOW DO BIRDS MIGRATE?

Its not fully understood, but…

HOW DO BIRDS MIGRATE?

Birds reproduce via internal fertilization  Embryo

Short incubation time - organism is more dependent at birth (sparrow)

Longer incubation – less dependent at birth (ducks)

Traits of Mammals Mammals are the most successful group of animals.

Mammals have hair or fur to insulate their bodies except for… Whales (blubber) and elephants (thick skin)

Mammals have mammary glands to produce milk for their young

Mammals have internal fertilization and development of their young

Mammals have a four chambered heart

Mammals have a very complex nervous system

Mammals have three main types of teeth: incisors, canines, and premolars and molars

There are three classes of mammals. The first are the monotremes. These lay eggs and their body temperatures vary much more than other mammals. The spiny anteater and duckbilled platypus are two monotremes

The second group of mammals is the marsupials. These bare their young in an undeveloped state with final development taking place in a pouch. Examples include the kangaroo, koala, and opossum.

The third group of mammals is the placentals. Young are completely developed at birth having received nourishment from the placenta. These include: 1. the insect eaters-shrews and moles

2. bats which fly and use sonar…

3. rodents-the largest group including beavers and hamsters whose incisors grow constantly

4. rodent-like with strong hind legs like the rabbit and the prairie dogs

5. aquatic mammals with fins, flippers, and streamlined bodies like the whales and dolphin

6. toothless mammals like the anteater and armadillo

7. meat-eating mammals like the dog, cat, and seal

8. hoofed plant eating mammals like the horse and deer

9. the elephants with trunks-males have tusks

10. primates with opposable thumbs and most complex brains

11. The seventh graders with their goofy behavior