midterm 3 reup

Question 1

4 important extraembryonic membranes

Answer 1

1 - amnion - surround embryo and watery amniotic fluid
2- chorioallantois - blood supply, respiration
3 - allantoic sac - holds wastes
4 - vitelline membrane - surrounds yolk

Question 2

What is the chalaza?

Answer 2

thin structure that keeps embryo centered and balanced in the egg

Question 3

What is the purpose of the air cell in eggs?

Answer 3

Gas exchange occurs through the shell, will increase as gas requirements increase

Question 4

3 important egg components?

Answer 4

Yolk - contains lipids proteins and water surrounded by vitelline membrane

Albumen - egg white - 90% water 10% protein - cushion / insulation

Shell - structural support / defense / gas exchange

Question 5

Why might cliff nesting bird eggs be oblong?

Answer 5

To prevent rolling off

Question 6

What does egg size / shape / pattern tell about bird ecology

Answer 6

often birds in the same family have similar eggs
- size is relative to size of bird
- camoflauge relates to environment
- eggs with no camo may be in better nests / better protected - cavity nesters

Question 7

What is interesting about the Common Murres eggs?

Answer 7

will have different camo depending on habitat

Question 8

How do birds keep their eggs cool?

Answer 8

will shade them or use damp breast feathers
- turn eggs to prevent adhesion and redistribute heat

Question 9

What is the relationship between incubation period and egg weight in birds?

Answer 9

more incubation time means more weight - linear

Question 10

What is piping ?

Answer 10

active hatching using egg tooth to break outer shell

Question 11

What is the hatching muscle?

Answer 11

strong muscles on back of bird necks for upwards reflex to break shell w egg tooth

Question 12

Why might hatching be synchronized in some precocial species

Answer 12

babies will run when born
- reduce time that chicks are waiting for parents / siblings to hatch

Question 13

Is altricial and precocial a gradient?

Answer 13

yes

Question 14

What is nidifugous and nidicolous?

Answer 14

nidifugous - young leave nest
nidicolous - young stay in nest

Question 15

What is imprinting?

Answer 15

within hours after hatching will follow largest object

Question 16

Costs and benefits of altricial v precocial

Answer 16

Altricial
Costs - high parental care, high energy requirement, high predation risk and potential loss of whole brood
Benefits - high growth rate, multiple broods and less investment / individual

Precocial
Costs - slow growth rate, harder to raise more than one brood
Benefits - less predation risk, less risk of losiong whole brood, low parental care, low energy

Question 17

What is the optimal breeding time?

Answer 17

variable, food and temperature limited
- often early is better for more development before migration but owls will start in winter to be old enough to hunt young birds in spring

Question 18

What is the role of hormones and photoperiod in breeding?

Answer 18

environmental light via neural receptors and the endogenous clock via pineal gland
- optimal time for reproduction
- synchronize pairs
- terminate reproduction

Question 19

Ultimate and proximate cues for breeding season?

Answer 19

ultimate - determined by nat sec
- food
- nest sites
- climate
- predation risk

proximate
- temperature
- habitat
- social interaction

Question 20

What is the role of hormones in reproduction>

Answer 20

to stimulate reproductiuon and induce ovulation

Question 21

What is prolactin?

Answer 21

hormone secreted by pituitary - signals switch from breeding to brooding behaviour
- rise during egg laying and incubation

Question 22

When do birds terminate breeding?

Answer 22

when no longer feasable to produce more young energetically

Question 23

How does breeding relate to moulting

Answer 23

molting stage is nonbreeding - will go breed if food is good and mate is present, will leave when food is bad, mate is gone or young have grown

Question 24

What birds may breed / molt in a non annual cycle?

Answer 24

tropical birds and seabirds

Question 25

When does colonial nesting occur?

Answer 25

many seabirds, when food and nest sites are not uniformly distributed

Question 26

Benefits of colonial nesting?

Answer 26

predator avoidance synchronized breeding will overwhelm predators - fraser darling effect

Question 27

Costs of colonial nesting?

Answer 27

Fighting disease parasite load confidence in paternity and maternity attract predators lost young infanticide limited by food supply and literal space for nests

Question 28

What is the optimal colony size?

Answer 28

somewhere in the middle bell curve, more individuals for group protection benefits but less parasite / disease

Question 29

Difference between song and call?

Answer 29

song - males during breeding call - both sexes yearround

Question 30

Difference between information calls and alarm calls?

Answer 30

Information calls - short and broad freq Alarm - faint long and narrow freq - hard to locate caller

Question 31

What season are most songs produced

Answer 31

late spring cuz breeding

Question 32

Why do birds sing

Answer 32

- different songs for different parts of territory - mate acquisition - individual recognition -dialect matches habitat

Question 33

What is repertoire correlated with?

Answer 33

condition of male

Question 34

How do birds learn what to sing?

Answer 34

some are soley genetic some are learned - usually have a critical learning period - usually in first 50 days but not always - go through a silent period -then subsong period where they practice what they remember - then song crystalization where the genetic auditory template is modified and they will be able to sing the song even if deafened later in life

Question 35

What is vocal mimicry?

Answer 35

used to intimidate other birds or impress females

Question 36

Why have courtship displays? 4

Answer 36

pair bonding synchronize sexual readiness stimulate hormonal cycles species recognition

Question 37

Define displays?

Answer 37

specialized acts that transmit information between sender and reciever

Question 38

What is the bet hedging strategy for egg laying?

Answer 38

if the optimal clutch size varies from year to year then you should always go for a larger than average clutch in a good year you can raise them all, if its a bad year you can sacrifice some eggs

Question 39

Why do nest parasites have an advantage?

Answer 39

usually have a lower incubation time to hatch early and give competitive advantage in the nest - sometimes will try to throw out other eggs - recieive more food

Question 40

Three models for mating systems

Answer 40

Social systems - old approach, includes pair and group bonding Mating systems - include actual genetic investment in offspring plus social interactions Cooperative breeding systems - usually seperate topic but a social option with both breeding and nonbreeding group members

Question 41

5 mating organizationa

Answer 41

Monogamy - 1m 1f Polygamy - multiple mates of one sex, could be either sex Polygyny - 1m multiple f Polyandry - multiple m 1f Promiscuity - little organization , males win

Question 42

5 terms for alternative mating strategies

Answer 42

EPC - extra pair copulation - mating outside a social pair bond EPF - extra pair fertilization - outside of pair bond Mate guarding - male watches female closely Mating tactics - strategies used by birds EPY - extra pair young - result of all the messing around

Question 43

What is the environmental potential for polygamy?

Answer 43

recognizes need for resouce abundance to make up for less parental care

Question 44

What is the result of high polygamy in terms of sexual selection?

Answer 44

crazy sexual selection

Question 45

Types of polygyny depending on external factors

Answer 45

rich territories = resource defence polygamy easy food / nests that are hard to defend = male dominancy ppolygny- leks females in groups = female defence polygyny - harems Mutualisms with fruit - male dominance polyygyny seen in tropics often leks

Question 46

Why might helpers exist in some social systems?

Answer 46

many species have excess populations with nowhere to go - will choose to help couple to pay rent

Question 47

Costs and benefits of helping in mating

Answer 47

benefits - helper stays alive hopefully to become dominant - gets inclusive fitness - learns - increase overall young raised costs - no breeding success - no guarantees of getting old parental site - may die before breeding - no effect on individual fitness (no reproduction)

Question 48

Illustrate the relationship between brood size and survival of young for an optimal clutch size of 6 eggs?

Answer 48

If the optimal size is 6 eggs, then anything above that number would decrease the survival of individual young as there are too many mouths to feed, survival decreases as brood size increases above the optimal - probably less effect on having fewer than six eggs, but would decrease number of offspring survived as there are fewer offspring

Question 49

Describe the spectrum of courtship displays and mate attraction in birds

Answer 49

Depends on how you define spectrum - less elaborate - calls and songs - more elaborate - bright color changes - can increase predation risk - very elaborate - courtship dances - can be risky for predator attraction - time and energy consuming - super elaborate - sexually selected structures ie peacock tails that pose great risk to own bird survivability

Question 50

Compare hatching synchrony and asynchrony, when is one preferred over the other?

Answer 50

Depends on species specific ecology - generally synchrony is preferred in precocial species to prevent chaos - asynchrony is preferred in altricial species for more managable feeding

Question 51

When does egg development begin?

Answer 51

Only at the start of incubation

Question 52

Which hormones are involved in reproduction?

Answer 52

FSH - stimulates gamete growth - sperm and eggs LH - induces ovulation