Bird Wings

Question 1

Describe feather structure

Answer 1

Vane composed of barbs
Barbules protrude form barbs with hooks called barbicels
Barbicels hook adjacent barbicels = strong and flexible vane

Question 2

Vane

Answer 2

Surface of feather

Question 3

Describe feather care

Answer 3

Preening
- Run feather through bill = linking barbules
- Dip beak into preen gland = oily waterproofing substance
dip beak into powder down
- feather will fragment = fine powder
- increases waterproofing and feather care
Dust baths
- smooth imperfections
Remove parasites

Question 4

Parasite removal e.g. ants

Answer 4

• spread wings and touch belly to ants nest
• Ants get onto skin and remove parasites = mutualism
• Birds preen ants away

Question 5

Moulting

Answer 5

• Flight feathers fray and get replaced
• normally after breeding period
• reduces flight efficiency so some birds lose one feather at a time = can take whole annual cycle to completely moult

Question 6

Evolutionary and current feather function

Answer 6

Epidexipteryx = earliest e.g. ornamental feathers
Today:
- mating displays
- against predation e.g. startle strategies
- predation

Question 7

Pigments in colour production

Answer 7

Carotenoids 
Quinones
Verdins
Porphyrins (iron, mg, copper)
Melanin

Question 8

Carotenoids

Answer 8

Yellow, red

E.g. flamingoes get from shrimp

Question 9

Quinones

Answer 9

Yellow
Red
Orange

Question 10

Porphyrins

Answer 10

Iron = red
Mg = green
Copper = red, violet, green

Question 11

Melanin

Answer 11

Dark brown
Black
Can indicate testosterone levels e.g. sparrows black badge indicates males quality

Question 12

How does scattering occur on bird patterning: blue

Answer 12

• Particles scattered into keratin structure of feather = transparent with dense particles sections
• some light absorbed by melanin below
• light hits = red light absorbed and blue light reflected
• striking blue. Also UV element birds see but we dont

Question 13

Scattering on bird patterning: multilayer interference

Answer 13

Different bands at different depths depending on feather density
- some light reflects off and some goes into deeper bands
Colour intensity depends on
- light angle
- density/width of bands
- pigments
Sometimes angle on incidence and wavelength can cause destruction of colour and sometimes enchanted eachother = constructive

Question 14

Bird internal temp

Answer 14

40C

Question 15

Giganothermy

Answer 15

Dinosaurs so large = low metabolic rate

Larger thermal inertia: heat more likely to spread round body than be lost

Question 16

Bird thermoregulation.

Answer 16

Little thermal inertia and high metabolic rate
Need to trap heat via insulation and waterproofing
Water would remove heat
Tuck head under wing when roosting to prevent heat loss form eyes and bill

Question 17

How can birds regulate their temperature

Answer 17

Completed homiothermy
Strategic hypothermia
Torpor
Hibernation

Question 18

Complete homiothermy

Answer 18

Constant temp rate of 40C

E.g. red jungle fowl

Question 19

Strategic hypothermia

Answer 19

Down regulate temp by 0-10C temporarily

E.g. great tits at night to conserve energy whilst sleeping

Question 20

Torpor

Answer 20

Reducing temp by more than 10C for less than a day
Become unresponsive
Often during harsh weather conditions
E.g. hummingbirds

Question 21

Hibernation

Answer 21

Reducing temp by more than 10C for over a day

E.g. common poorwill over the winter period

Question 22

Why do birds fly

Answer 22

Escape predation 
Catch prey 
Safe nest sites 
Extending home range 
Display flights

Question 23

What are the differnt theories of flight evolution

Answer 23

Trees down model
Wing assisted pouncing model
Ground up model
Wing assisted incline running 
Wing assisted water walking

Question 24

Trees down model of flight evolution

Answer 24

Jumping off a high point
Seen in other animals e.g. flying squirrels = dont need wings to achieve
Foot morphology shows birds wouldn’t have been able to climb trees however doesnt rule out cliffs etc.

Question 25

Wing assisted pouncing model of flight evolution

Answer 25

Catching prey from vantage point and swooping down on them

Could explain archaeopteryx poorly adapted for flapping yet advanced asymmetrical aerodynamic feathers

Question 26

Ground up model for flight evolution

Answer 26

Birds run along ground and flapped wings to go faster

Eventually turned into lift

Question 27

Wing assisted incline running model for flight evolution

Answer 27

Up stroking the wings to increase feet grip

But archaeopteryx had weak upstroke

Question 28

Wing assisted water walking

Answer 28

Flapping wings helped the birds to walk across water

However reptiles can do this without wings

Question 29

How are wings adapted to fly?

Answer 29

Aerofoil shape
- air travels further on upper surface than lower = faster velocity, lower pressure
Increasing angle under wings increases lift but reduces forward momentum
Flapping
- downstroke increases pressure on underside = lift
- wing partly folded and flexed on upstroke

Question 30

E.g. how diff bird wings adapted to diff priorities

Answer 30

E.g. penguin for underwater
E.g. magpie for stable flight
E.g. vulture for soaring flight

Question 31

Asymmetrical feathers

Answer 31

= pennaceous
Aerodynamic
Smaller on one side

Question 32

Specialisation of feathers around the head

Answer 32

Around beak = bristle feathers
- widens area bird can catch prey (insects)
Under he outer contour feathers there is dense down layer = insulation