Vertebrates 12 - Flight

Question 1

Parachuting

Answer 1

More or less falling a little slower than normal. Light body, some surface area. Generally small animals like tree frogs

Question 2

Gliding

Answer 2

Longer horizontal movement. Some lizards, flying squirrel, flying fish

Question 3

Flying fish

Answer 3

Can glide up to 200m! Disadvantage because the fins are big. Once out of water it undulates the tail to shake out the fins, then relaxes and glides

Question 4

Flying snake

Answer 4

Able to flex their ribs so their ventral surface is quite flat, provides surface area.

Question 5

True fliers

Answer 5

Pterosaurs, birds and bats. Able to fly long distances, take off from flat surfaces. Convergent evolution

Question 6

Shape of wing

Answer 6

The Airfoil. Fusiform so little drag. Asymmetric, flat on bottom, bump on top. Air moves faster across the top, creates lower pressure on top, which creates lift.

Question 7

Formula for Lift.

Answer 7

L = 1/2 p(V^2)SC1 . p is density of air, V is speed, S is surface area, C is the angle of the wing (angle of attack)

Question 8

Slow flying birds

Answer 8

Slow speed, so they need higher surface area to compensate. Ex. vultures

Question 9

Fast flying birds

Answer 9

Heavier birds. Wings aren’t that big. The only way to stay in the air is to fly rapidly. Need to build up speed before lift is created Ex. Loons, ducks.

Question 10

Wingloading

Answer 10

Weight of bird/surface area of wings. (vulture is .3, loon is 1.4). Indicates how fast bird must fly

Question 11

What is the minimum amount of lift needed to fly?

Answer 11

Needs to be at least equal to the weight of the bird

Question 12

Misconception with flight

Answer 12

That flapping causes flight. False! It is air moving over the airfoil. Flapping causes forward thrust, which makes more lift.

Question 13

Downstroke and muscle needed

Answer 13

Pushes air backwards, creating forward thrust. Pectoralis muscle.

Question 14

Upstroke

Answer 14

Want to minimize friction. Sometimes feathers turn (due to asymmetrical structure) and allow easier raising. Also called recovery

Question 15

Flapping in bat

Answer 15

Heavier membrane, more flapping is required. Shape etc. causes more pressure drag, which slows it down and requires energy, but also increases maneuverability.

Question 16

Hummingbirds flapping

Answer 16

Normal flight: pretty similar to other birds. But it can also hover! Lift created on forward stroke, moves in figure 8. Flaps 15-80/s, other birds 12-70/min

Question 17

Soaring

Answer 17

Two types: static and dynamic. Conserve energy.

Question 18

Static soarers

Answer 18

Live in hot environments. Use thermals to gain lift: areas with hot air rising helps raise them. Vultures, condors. Wing loading is low, large SA

Question 19

Dynamic soarers

Answer 19

Live near water, use coastal winds to create lift. Long wings give high SA. Albatross.

Question 20

Video: How do birds adjust their bodies to prevent excess energy loss?

Answer 20

Fast: makes itself more streamline, horizontal, retract feet, open mouth to fill air sacs and get O2. Muscle expenditure doesn’t increase. Slow: flexes out tail to increase lift surface. (more difficult, more energy). Head is stable

Question 21

Video: How are fixed wings (in planes) better than flapping wings?

Answer 21

Fixed are more stable, especially with falling, but they are less maneuverable. (intense new fighter planes are less stable but more agile)

Question 22

Summary: Bird adaptations

Answer 22

Light skeleton (no teeth, spongy bone, feathers); large sternum and keel for muscle; rib spurs to support thoracic cavity from collapsing; breathing adaptations; reproductive (only one ovary); nutritional (high energy food)

Question 23

Evolution of bird flight

Answer 23

1. Arboreal theory. 2. Running flight. 3. WAIR.

Question 24

Arboreal theory of flight

Answer 24

Many dinos lived in forests, many probably climbed. Might have developed enough feathers to glide, then fly.

Question 25

Running flight theory

Answer 25

Therapods weren’t climbers since they had weak forelimbs. Could run and jump, feathers could help them jump farther.

Question 26

W.A.I.R theory

Answer 26

Wing-assisted inclined running. Wings help climb steep surfaces (to escape predators). Seen in young birds who can’t fly yet, but can climb.

Question 27

Graph: Most energy costly locomotion

Answer 27

Burrowing most: dense. Runners next. Fliers and swimmers least, buoyancy.