Bird Exam Study

Question 1

Thecodont hypothesis:

Answer 1

Birds evolved from thecodont reptiles about 230 million years ago.

Question 2

Theropod hypothesis:

Answer 2

Birds evolved from theropod dinosaurs about 150 million years ago.

Question 3

Respiratory system in birds:

Answer 3

•Air moves from outside bird into posterior air sacs by trachea.
•Air moves from posterior air sacs to lungs.
•Air moves from lungs to anterior air sacs.
•Air moves from anterior air sacs our body by trachea.

Question 4

Reproduction in birds:

Answer 4

•Testes large during reproduction.
•Testes atrophy in non-breeding season.
•Most don’t have a penis.
•Sperm can be stored for weeks between vagina and shell gland for later use.
•Brood patch is a featherless patch that warms egg.

Question 5

Feather characteristics:

Answer 5

Functions:
•Flight.
•Display.
•Camouflage.
•Waterproof.

Color:
•Pigments.
•Structure.

Question 6

Flight in birds:

Answer 6

•Lift is generated by the secondary feathers and breast muscles.
•Thrust is mainly generated on the downstroke by the primary feathers.
•Drag counteracts thrust and is caused by the friction between wing and air. Coverts streamline the wing to reduce drag.
•Weight counteracts lift but birds have adaptations to reduce weight (little fat, hollow bones, single ovary).

Question 7

Different kinds of flight:

Answer 7

•Gliding.
•Thermal soaring.
•Soaring using updrafts.
•Dynamic soaring.
•Powered.
•Bounding.
•Hovering.

Question 8

Fields of vision:

Answer 8

•Peripheral (on sides to spot predators).
•Binocular (in front to spot prey).