Birds

Question 1

Birds evolved from?

Answer 1

predatory dinosaurs

Question 2

Intermediates fron Jurassic (3)

Answer 2

1) Archaeopteryx
2) Aurornis
3) Anchiornis

Question 3

General features of Archaeopteryx, Aurornis, Anchiornis

Answer 3

Clawed digits on forelimb
sharp teeth
long bony tail

Question 4

Specialized derived traits for Archaeopteryx (2)

Answer 4

Flight feathers

Fused clavicles for Furcula (wish bone)

Question 5

Furcula

Answer 5

Wish Bone

Strengthens thorax for flight

Question 6

Which ancestor contained the feathers of modern birds

Answer 6

Archaeopteryx

Question 7

Oviraptorosaurs had comparatively (long/short) forelimbs but (long/short) feathers

Answer 7

Short forelimbs

Long feathers

Question 8

Theropod (Digit length)

Answer 8

small IV and V digits

Digit III the longest

Question 9

Coelophysoids (digit length)

Answer 9

Digit V lost

Digit II and III equal length

Question 10

Allosaurids and Dromeosaurids (digit length)

Answer 10

Digit IV lost

Digit II longer than III

Question 11

Adaptations which gradually lead to flight (5)

Answer 11

1) Loss and fusion of bones (vertebrae and bones of pelvic girdle)
2) Reduction in body size
3) Outer cortex of bones: Thinner but more dense
4) Bones are hollow but have Trabeculae

Question 12

Trabeculae

Answer 12

Cross bridges of bones within long portion for stabilization and allowing bones to be more light weight

Question 13

3 Aspects of bird evolution (besides hollow bones)

Answer 13

1) Sternum became larger
2) Forelimbs became longer than hindlimbs
3) Teeth were lost repeatedly in different lineages

Question 14

Birds are the (#) largest class of vertebrates

Answer 14

Second largest

Question 15

Successful attributes of bird evolution (2)

Answer 15

1) Endothermy

2) Flight

Question 16

Bird Skin

Answer 16

1) Thinner & highly vascularized
2) Thin skin in feathered areas (10 cells thick)
3) Dermis thinner than mammals
4) Comb and wattles thickened and heavily vascularied for increased arterio-venous anastomoses

Question 17

Bird Brood patch

Answer 17

Breast of incubating birds
Thickened and heavily vascularized
Loss of feathers
Heat transfer to eggs

Question 18

Bird Beak

Answer 18

Keratinized structure

Grown continually

Question 19

Bird Spurs

Answer 19

Bony core and keratinized sheath
Especially in make chook and turkey
Develops after 6 months of age

Question 20

Bird Scales

Answer 20

Section of highly keratinized epidermis

Question 21

Bird Uropygial Gland (4)

Answer 21

1) Found at the dorsal surface of tail
2) 2 Lobes that open to single papilla
3) Tuft of feathers
4) Lipoid secretion (waterproofs and moisturizes feather/beak/scales)

Question 22

Pterylae

Answer 22

Feather arranged in well-defined and linear tracts

Question 23

Apteria

Answer 23

Featherless areas exist between the pterylae

Question 24

3 Types of Feathers

Answer 24

1) Contour feathers
2) Flight feathers
3) Down feathers

Question 25

Contour Feathers

Answer 25

Covers most of the body
Aerodynamics
Protection

Question 26

Flight Feathers

Answer 26

Larger and stiffer than contour feathers
Flight feathers on the wings (Remiges)
Flight feathers on the tail (Retrices)

Question 27

Remiges

Answer 27

Flight feathers found on wings
Primary: called “manus”
Secondary: Called “ulna” (antebrachium)

Question 28

Down feathers

Answer 28

Positioned between flight and contour feathers
- insulation
Chicks have natal down feathers

Question 29

Bird Bones

Answer 29

Light but strong (high CaPO4 concent.)

Pneumatic bones

Question 30

Pneumatic bones and examples

Answer 30

Bones with diverticula (invasions) of air sacks

Examples: Vertebrae, pelvis, sternum, costal bones, humerus, femer

Question 31

Bird Skull

Answer 31

Evolved from diapsid reptilian skull

• Enlarged cranium
• Jaws toothless
• Skull prokinetics

Question 32

Skull prokinetics

Answer 32

Premaxilla and nasal bone from hinge with frontal bone

Upper jaw can be raised as lower jaw depressed

Question 33

Bird Lungs

Answer 33

Lung site of gas exchange, not air sacks
Unlobed
1/10th size of humans, just as heavy

Question 34

Bird Air Sacks

Answer 34

Thin walled extensions of bronchi
Blind-ending
Key role in respiration but not gas exchange

Question 35

Bird Heart and Circulatory system

Answer 35

Double circulation system
Heart completely divided 
Higher metabolic rate than humans 
Higher blood pressure
Chook: 350-470bpm
Quail: 1000bpm

Question 36

Double circulation system in birds

Answer 36

1) Pulmonary

2) Systemic

Question 37

Bird: Male Reproduction

Answer 37

Males have Phallus
- tubercle on ventral wall of vent
- Protrusible in ducks and geese
At copulation: Vent everted in both sexes and phallus pressed to females cloaca

Question 38

Bird: Female Reproduction

Answer 38

Left ovary and left oviduct
Right ovary and oviduct regress in embryo
Ovary contains large yolk-filled oocytes
Oviduct is the site of fertilization 
Oviduct has 5 regions

Question 39

Bird Ear

Answer 39

Similar to mammals
External ear covered by covert feathers
Middle ear similar to humans
Contain tympanic membrane 
Inner ear similar to mammals

Question 40

Bird: Brain

Answer 40

Proportionally small (exception corvids)
Cerebellum: relatively large (coordination of muscle and balance during flight)
Optic lobes: Very large

Question 41

Most intelligent birds

Answer 41

Pigeons, Crows, and Parrots