1. Birds

2. Class: Aves 29 Orders 8,600 species
Thought to have come from reptiles because they:
1. Lay amniotic eggs
2. Have scales on legs

3. General Characteristics
Endotherms-heat comes from within the body
Feathers help with insulation
4 chambered heart
Must have good senses
Vision: most birds have good eyesight
Visual and motor areas of the brain are well developed

4. What is a bird? Reptile like Maintain a constant body temperature
Have feathers
Have 2 legs that are covered with scales
The majority of birds can fly, but those that can’t move by walking, running, or swimming.
Ratites-birds that don’t fly
keel is subtle or absent and lacks muscles to fly
Carinates-have a keel and can fly

6. Feathers
Made mostly of protein called keratin, and develop from pits in the bird’s skin.
Help with flight and insulation
3 Types of feathers:
Contour
Provide lift and balance needed for flight
Down
Trap air close to body for insulation
Powder down (in birds that are around water)
Powder repels water

7. Vane
Rachis
Barb
Afterfeather
Hollow Shaft

9. Evolution of Birds Thought to have come from extinct reptiles
Archaeopteryx: First birdlike fossil
From Jurassic Period (150 mya)
Looked like a small running dinosaur except it had feathers
Unlike birds, it had teeth in it’s beak, a bony tail, and toes and claws on it’s wings

11. Comparison of Reptiles and Birds
Embryos develop in amniotic eggs
Excrete waste in the form of uric acid
Bones in front and hind limbs are very similar

12. Bodies are Modified for Flight
Bones:
Honeycombed (hollow) inside
Makes the bird lighter
Organs:
Missing some to make bird lighter
Only 1 ovary
No teeth (food is ground up in the gizzard)
Crop (part of the digestive system used to store food)
Beak:
Make of keratin (lighter than bone)
Different shapes for different diets and is also aerodynamic

14. Flying Requires good coordination and lots of energy
Flap wings using large pectoral muscles (breast) anchored to a keel on the sternum
Some have wings adapted for soaring and only have to flap occasionally
Others have to flap continuously to stay in flight (hummingbird)
Wings work using Bernoulli’s principal
Video on Pectoral Muscles

15. Advantages of Flight Hunting and scavenging
Catch insects (good source of nutrition)
Escape predators
Can migrate farther

16. Digestion
Birds don’t have teeth, so they have to break down food using a crop
At the end of the esophagus, it stores and moistens food before it enters the stomach
In some birds, during nesting season, the crop produces a protein rich substance that they regurgitate to their young

17. Beaks Adapted to the food they eat Insect eating: short, fine bills
Seed eating: short, thick bills
Carnivores: strong, sharp, hooked bills
Nectar eating: long, thin bills
Fish eating: large, long bills

18. Digestion Birds that eat insects or seeds have a gizzard
Forms part of the stomach
Birds swallow stones or small pebbles to help grind up the food
Waste leaves through the cloaca

19. Respiration
When birds inhale, the air passes into air sacs in the body cavity and in the bones.
It then passes through the lungs on the way out of the body.
While in the lungs, oxygen is absorbed into the blood stream.
This is a one way flow of oxygen rich blood.
Helps birds fly at high altitudes where air is thin.

20. Circulation Have a 4 chambered heart.
Oxygen rich blood is separate from oxygen poor blood.

21. Response Have well adapted sense organs.
The brain is relatively large for the body size.
Have highly developed eyes that see color very well.
Taste and smell are not as developed.

22. Reproduction
Reproductive tracts open into the cloaca in both male and female birds.
Sex organs sometimes shrink when not mating.
Mating birds press their cloaca together to pass sperm into the female (not all birds have a penis)
Birds incubate their amniotic eggs until they hatch.
Chicks use a small tooth on their bill to crack the egg.
After exiting the egg, it rests and allows the feathers to dry.

23. Groups of Birds Loons and Grebes Loons
There are about 5 species of loons
4 can be found in the US
Gather food by diving and chasing fish
Grebes
27 species worldwide
7 can be found in the US
Food gathering similar to the loon
Found in more diverse habitats than loons

24. Groups of Birds Albatross 14 species worldwide Petrels
The Pelagics
Albatross
14 species worldwide
Petrels
20 species worldwide
Shearwater
70 species worldwide

25. Groups of Birds
Pelicans and relatives (ex. Cormorants, boobies, and frigatebirds)
Found in all aquatic ecosystems
Have 4 toes connected by a web

26. Groups of Birds Parrots (Macaws, lovebirds, and cockatoos)
Colorful and noisy
Use feet to hold food
Most typically mate for life
Beaks can crack open seeds, nuts
Tongues have a bone that can help them tap into fruit
Very social

27. Groups of Birds
Perching Birds (ex. Sparrows, crows, mockingbirds, and cardinals)
Called passerines
Largest order of birds
Many are songbirds
Herons and relatives (ex. Storks, ibises, spoonbills, herons, and cranes)
Adapted to wading in aquatic habitats

28. Groups of Birds
Ostriches and relatives (ex. Emus, rheas, cassowaries, and kiwis)
Flightless
Must move by running or swimming
Cavity Nesting Birds (ex. Barbets, toucans, and woodpeckers)
Multicolored
Live in holes in trees, mounds, or underground tunnels

29. Groups of Birds
Birds of Prey (ex. Condors, hawks, owls, eagles, and falcons)
Also known as raptors
Fierce predators with hooked bills
Large wingspans
Sharp talons

30. Ecology of Birds
Can pollinate flowers (mockingbirds), seed dispersal, and control insect populations.
Migration
Usually seasonal
Some species use stars to navigate others use landmarks or the earth’s magnetic field
Indicators for environmental health
Songbird eggs became very fragile because of the pesticide DDT and their population was nearly extinct

31. Common Birds around here

32. Common Birds around here

33. Common Birds around here

34. Common Birds around here

35. Common Birds around here

36. Common Birds around here

37. Common Birds around here

38. Common Birds around here

39. Common Birds around here

40. Common Birds around here

41. Common Birds around here

42. Common Birds around here