Lecture 20: Birds

Question 1

Shared characteristics between bird and theropod dinosaur

Answer 1

• 3 hinged tow
• bipedal
• 4 chambered
• similar lungs
• feathered

Question 2

Archaeopteryx

Answer 2

• crow sized
• had feather & wings
• had teeth & bony tail (like non-avians)

Question 3

Darwins Finches

Answer 3

• had diversity of beaks depending on what they eat

Question 4

Thermoregulation

Answer 4

• allows them to occupy extreme environments

Question 5

Ectoderm

Answer 5

absorbs external heat

Question 6

Endoderm

Answer 6

generates own heat through metabolic processes

Question 7

Behavioural thermoregulation

Answer 7

changing orientation relative to heat source

ex. moving locations throughout the day
ex. putting on a sweater

Question 8

Physiological Thermoregulation

Answer 8

too hot - sweat
too cold- shiver
- using hypothalamus to regulate hormones and responses in order to maintain temperature

Question 9

Physical Thermoregulation

Answer 9

• insulation
• colour
• Surface area

Question 10

Ventilation in birds

Answer 10

breath 1:
- air is drawn into posterior air sacs
- air is propelled thru the lung
breath 2:
- same air drawn into anterior air sacs
- same air propelled out through nares

Question 11

Adaptations for flight

Answer 11

• hollow bones
• sternum enlarged and kneeled (allowed for increased SA for attachment of large flight muscles
• feathers (originally evolved for insulation)

Question 12

Feathers

Answer 12

Function: 
insulation
flight
sensory structures
lining nests
Made of: keratin (derived from scales)
Birds have reptile like legs

Question 13

How do wings enable flight?

Answer 13

• object changes air flow pattern and creates a lift

- particles must move faster to get over bump