Birds

Question 1

What does ratite mean?

Answer 1

flat sternum with no keel; flightless

Question 2

what does carinate mean?

Answer 2

birds that have a large keel + able to fly (for the most part)

Question 3

what is a pneumatic skeleton?

Answer 3

hollow + reinforced bones to reduce weight to allow for flight

Question 4

what are the general characteristics of birds?

Answer 4

• Feathers
• Forewings modified as wings
• Hollow bones
• Air sacs
• Endothermic
• High metabolism
• Four chambered heart

Question 5

What are the 3 reasons why Archaeopteryx and feathered dinosaurs is not evidence of evolution of birds from reptiles?

Answer 5

• A mosaic animal is not necessarily a transition
• Transitional structures should be seen (feathers)
• New complex structures need to evolve

Question 6

what are the basic parts of a feather?

Answer 6

vane, shaft, quill

Question 7

what is the vane?

Answer 7

flat portion needs to hold together as a flat surface to provide lift in the air

Question 8

what is the shaft of a feather?

Answer 8

where the vane attaches

Question 9

what is the quill?

Answer 9

hollow, bare base to supply nourishment during growth

Question 10

how is the growth of feathers different from mammal hair?

Answer 10

a bird’s feather dies when it is fully grown

Question 11

how do birds change the color of their feathers?

Answer 11

o molting of bird feathers is how some species change color
o one set of feathers is lost and a new set of a different color is grown in their place the next season

Question 12

In what four ways is a bird’s skeleton different than ours to allow flight?

Answer 12

• Pneumatic (hollow, reinforced) bones
• Teeth replaced by light bill
• Vertebrae mostly fused for rigid body to support wings
• Forelimb bones modified and fused for strength and designed to hold feathers to produce lift

Question 13

In what three ways do bird muscles allow flight?

Answer 13

• Large mass -> provide energy
• Low center of gravity
• Muscle that raises wing lies under the wing + attaches to upper wing surface by a rope and pulley tendon

Question 14

How is a bird’s body temperature related to metabolic rate and to conditions necessary for flight?

Answer 14

• Birds lungs: Air sacs give one-way air flow
• In a mammal lung: air sacs give two-way flow

Question 15

How is the bird’s 4 chambered heart different than a mammal heart to allow flight?

Answer 15

the bird lung is larger and more powerful than that of a mammal, and beats faster, to deliver blood more efficiently

Question 16

What kind of excretory waste does a bird have and how does this allow flight?

Answer 16

• it converts its digestive wastes into uric acid
• Uric acid is much less toxic than urea, and so it can be concentrated to save weight without being too toxic

Question 17

How does bird vision differ from ours?

Answer 17

• Larger eyes than mammals
• Abundant cones in eyes for visual acuity (2-3x that of mammals)

Question 18

How do birds navigate during migration?

Answer 18

o Eyes sensitive to ultraviolet light
o Sensitive to magnetic fields
o Brain capable of using both the sun and stars as a compass