1. Chapter 26
Reptiles and Birds

2. Reptile skin Dry, thick, with scales Prevents water loss
Provides protection

3. Reptile heart / lungs Use lungs for breathing
Most have 3-chambered hearts
Crocodilians – 4-chambered hearts
Completely separates oxygen-rich blood from oxygen-poor blood
Supports higher level of energy use

4. Skeletal changes Leg position (under body) provides better support
Makes running / walking easier
Easier to catch prey / avoid predators
Claws used to get food / protection
Jaws and teeth

5. Reptile reproduction Lay eggs on land No larval stage
Hatchlings resemble adults, only smaller
Amniotic egg nourishes embryo and provides protection
Internal fertilization
No care for hatchlings (except crocodiles)

6. Other reptile characteristics
Ectotherms-body temperatures depend on temperature of environment
Don’t live in cold regions
Prefer warm or hot climates
Become dormant during cold months

7. Reptile adaptations Turtles and tortoises Lizards Snakes
Most hervibores
Predators eat worms, mollusks, fish
Lizards
Eat insects
Snakes
Small mammals

8. Snake sense organs
Heat-sensitive organs allow them to detect variations in air temperature (warm-blooded animals)
Jacobson’s organ-used to smell

9. Turtle adaptations Shells protect Powerful jaws but no teeth
Live in water, (tortoises on land)

10. Crocodiles Don’t migrate Jaws and teeth, used to drown their prey
Lays eggs on land
Guard nests

11. Lizards
Found in all habitats except polar regions
Jaws and teeth

12. Snakes No limbs Found in all regions except polar areas
Kill prey in three ways
Constrictors wrap around and squeeze
Venomous snakes inject toxin with fangs
Most swallow prey whole

13. Birds Class Aves Fossil evidence show evolution from thecodonts
Clawed toes on feet
Internal fertilization
Amniotic eggs with shells

14. Feathers Lightweight, modified scales
Provides insulation and enables flight
Preening with the beak / bill keeps feathers clean and oiled for water-proofing
Feathers molted usually in summer and new ones grow

15. Bird bodies Front limbs modified into wings
Powerful flight muscles attached to sternum and upper bone of each wing (to generate lift)
Requires large amounts of energy; eat large amounts of food
4-chambered heart
Endotherms-control own temperature
Live in all environments

16. Bird adaptations Feathered legs-walk in snow
Wings / feet adapted for swimming
Insulating fat
Large eyes, acute hearing, sharp claws
Shape of beak adapted for specific food

17. Mammals Active, large-brained, endothermic animals
Complex social, feeding and reproductive behaviors
Come in many different shapes and sizes

18. 4 characteristics shared by ALL mammals
Hair
Mammary glands
Middle ear containing 3 bones
Jaw to chew food

19. Hair Most species are covered with it
Used to retain heat by trapping a layer of air close to the skin
Can be used for behavioral displays (puffing up when frightened)
Can be used for camouflage
Specialized hairs (whiskers) help with sensory information

20. Mammary glands Glands that produce milk to feed the newborn young
Milk contains water, sugars, protein, fats, minerals, and antibodies
Found in both sexes of all species but only produce milk in females

21. Middle ear 3 small bones (stapes, malleus, incus)
Vibrations of the eardrum are transferred through the malleus and incus bones to the stapes
Vibrations are converted into nerve impulses in the inner ear and interpreted by the brain
Allows mammals to hear high-pitched sounds

22. Chewing
Begin to break up food in the mouth (rather than starting in the digestive tract)
Secondary palate separates the nasal and oral cavities so mammals can eat and breathe at the same time
Complex muscles control movement of the jaw

23. 3 groups of mammals 1. monotremes Lay eggs
3 species (platypus, 2 types of echidna)
Retain some reptilian features (sprawling posture, single external opening, amniotic eggs with leathery shells)
Some mammal features (hair, mammary glands)

24. 3 groups of mammals
2. marsupials- 282 species including kangaroos, wombats, Opossum, koalas
Give birth to under-developed young that must complete development inside a pouch
Tiny young must attach themselves to a nipple inside the pouch for feeding during development

25. 3 groups of mammals 3. eutherian mammals
Give birth to live young that completed development internally
Often called placental mammals
Parental care is necessary to protect young after birth when they are most susceptible to predators