basic characteristics

Question 1

strutted bones

Answer 1

create a lot of airspace to reduce weight for flight

Question 2

testes

Answer 2

change in size from breeding to nonbreeding seasons to reduce weight

Question 3

feathers

Answer 3

a diagnostic characteristic of birds, keratin based

Question 4

feather structure

Answer 4

a central rachis with extended barbs, barbules extend from barbs, and barbicels extend from barbules and interlock to maintain structure

Question 5

contour feathers

Answer 5

used for insulation and flight can be symmetrical or asymmetrical

Question 6

semiplumes

Answer 6

feathers with shorter barbs making up the body volume above the downy feathers

Question 7

down feathers

Answer 7

short rachis and longer barbs for insulation

Question 8

powder down

Answer 8

some downy feathers break down leaving a dusty coating helping the contour feathers last longer, providing waterproofing, and discouraging mites

Question 9

bristle feathers

Answer 9

have little or no vane

Question 10

filoplume

Answer 10

long vanes to stand up for display purposes

Question 11

pterylae

Answer 11

feather tracts, allow for muscular control for display and insulation purposes

Question 12

primaries

Answer 12

main flight feathers, most species have 9-12, with flightless birds on both the extremes

Question 13

apteria

Answer 13

featherless patches to allow for foot or head tucking, heat release, and some display purposes

Question 14

uropygial gland

Answer 14

produces oils used to coat feathers

Question 15

preening

Answer 15

smooths feathers, spreads oils, and removes molting feathers

Question 16

anting

Answer 16

allowing ants to bite leaving behind formic acid which can be spread to repel mites

Question 17

bathing or dusting

Answer 17

rolling in water dust or sand to clean feathers and remove mites

Question 18

molting

Answer 18

replacing old feathers in seasoned cycles to replace worn out or broken feathers or for breeding plumage; most birds cannot control this cycle

Question 19

incubating patch

Answer 19

a spot where females remove feathers on the belly to create skin contact with the egg

Question 20

Bernoulli effect

Answer 20

pressure is inversely related to the number of particles moving in a certain direction

Question 21

Newton’s 3rd law

Answer 21

for every reaction there is an equal and opposite reaction

Question 22

lift generation

Answer 22

air moves faster above the wing than below creating lower pressure above the wing and higher pressure above

Question 23

angle of attack

Answer 23

runs from highest part of the wing to the tip, a higher angle creates less pressure below allowing for more lift but too big of an angle prevents lift and causes stalling

Question 24

alula

Answer 24

a finger projection over the primary feathers smooths the airflow over the wing during low speed flight and a high angle of attack

Question 25

aspect ratio

Answer 25

length/width; indicates what environment a bird lives in, high aspect ratios have lower wing loading

Question 26

wing loading

Answer 26

body mass/wing area; heavy birds have higher wing loading,

Question 27

modes of flight

Answer 27

gliding, soaring, flapping, hovering, and formation flying

Question 28

formation flight

Answer 28

allows the air generated by the leading bird to reduce the energy required of the followers

Question 29

flapping flight

Answer 29

downstroke is the power stroke and the upstroke is recovery and attempts to minimize drag, aided by wing slotting