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Flashcards in Zoology Final c Deck (34):
1

unique characteristic of birds

- feathers
- evolved from reptilian scales
- makes possible their greatest adaptation - flight

2

structure of feathers

- barbs arise from main feather shaft
- each barb has its own shaft from which the barbules arise

3

which feathers are responsible for birds ability to fly?

- remiges
- primaries
- secondaries

4

remiges feathers

feathers on the wings

5

primary feathers

provide forward propulsion to move the bird through the air
- asymmetrical vanes: the leading vane is relatively narrower than the trailing vane, so that the primary twists as it is pulled downward, acting like propeller

6

secondary feathers

provide lift to keep the bird in the air
- wing is curved in cross-section so that air travels relatively faster over the top of the wing
- the faster air travels, the less pressure it exerts on a service
- Bernoulli effect

7

high speed wings

- longer than wide, taper
- no wing slots

8

broad, rounded wings

- good maneuverability
- low speed flight

9

soaring and gliding wings

- much longer than wide
- high speed

10

long, slotted wings

- terrestrial soaring birds
- can carry heavy loads

11

characteristics of tail feathers

- rectrices
- symmetrical
- responsible for braking, maneuverability and also provide lift

12

characteristics of down feathers

- have barbules that do not interlock
- evolved for purpose of insulation; preceded flight feather, since warm-blooded animals need to be insulated to keep heat in

13

what muscle is responsible for downstroke of birds wing and where does it attach

- pectoralis and attaches on the ventral humerus from the keel

14

what muscle is responsible for the upstroke of birds wing and where does it attach

- supracoracoideus and attaches on the dorsal humerus from the keel

15

what adaptations are found in feet of perching birds

mechanism by which toes auto magically tighten around perch when they land on it, enabling them to perch with minimum of muscular effort

16

respiratory system in birds

one way flow of sir through lung increase efficiency

17

one-way flow of air

- air from trachea bypasses lungs and enters the posterior air sacs
- air passes from posterior air sacs through lungs to anterior air sacs
- air passes from anterior air sacs back out of trachea

18

flight adaptations

- air sac system reduces eight of bird which increase power/weight ratio
- reduced weigh tof skeleton without reducing its power by extending air sacs through hollow, pneumatic bones reinforced by struts
- birds have relatively large heart
- sexual organs atrophy during non-breeding season, and only left ovary develops during breeding season
- homiothermic which allows for higher metabolic rate

19

homiothermic

warm-blooded

20

brain of the bird

- cerebral cortex
- hyperstriatum
- cerebellum

21

cerebral cortex

poorly developed, and is not associated with higher behavioral processes as it is in mammal

22

hyperstriatum

higher behavioral processes are centered here
- not found in mammals

23

cerebellum

relatively large in birds, need for extreme muscular coordination
- smarter behavior

24

bird vision

- extremely good visual acuity, due to much greater density of cone cells in fovea of retina
- fovea is region of keenest vision
- some birds have two fovea to focus in two places simultaneously

25

hawks and eagle vision

- have telescopic eyes to magnify objects
- visual acuity of hawk is 8 times that of human, enabling it to see food more than a mile away

26

reproduction in birds

- an extremely efficient digestive system allows nestlings to leave nest as soon as possible
- two types of young: altricial and precocial

27

altricial young

- born blind, naked and helpless

28

precocial young

- born fully-feathered and mobile

29

bird migration

- experimental evidence has shown that the sun, stars and earth's magnetic field are all involved, depending on the species
- undertake very long migrations

30

neotropical migrants

- 170000 sq km of tropical rainfoest is lost a year
- tropical rainforest is home to neotropical birds
- includes those of songbirds
- forest fragmentation

31

how many birds are killed my cats a year

19 million

32

forest fragmentation

- split forests into sections
- causes increased predation because predators hunt on the borders and when split into different sections that results in more borders

33

cowbird parasitism

- brown-headed cowbird lay eggs in other birds nest, since cowbirds are bigger, they get fed over songbirds which causes the songbirds to die

34

what very important fossil is very strong evidence of relationship between birds and reptiles?

- Archeopteryx
- reptilian skeleton, but with true feathers