Lecture 14

Question 1

Drivers of sexual selection:

Answer 1

male-male competition and female choice

Question 2

why does bright red, orange and yellow plumage signal good health?

Answer 2

carotenoid pigments are vitmain precursors and must be obtained from the diet. Must be good foragers

Question 3

what does the comb size of a chicken tell you?

Answer 3

comb size is reduced in chickens with nematode parasites and large combs also are associated with more testosterone.

Question 4

what does it tell you if long ornamental feathers are frayed or shortened?

Answer 4

probably done so by feather parasites or not grow as long f the brd is not in good health.

Question 5

what does the bobolink do to display its health?

Answer 5

does a costly flight display

Question 6

How do bowerbirds attract mates?

Answer 6

build complex display structures instead of using their plumage. Shows male quality as they still have to compete for objects

Question 7

are birds predominantly promiscuous or socially monogamous making pair bonds?

Answer 7

90% are mongamous

Question 8

how do bonds end?

Answer 8

death or divorce

Question 9

Frequency of divorce depends on what?

Answer 9

life history! costs and benefits of pair fidelity

Question 10

what are 3 reasons why a pair might divorce?

Answer 10

1. trying to find them after migration 2. Costs of mainting the bond year round, just give up. 3. Assess partners performance and decide whether to change mates

Question 11

what are 3 hypotheses for divorce?

Answer 11

1. Improve reproductive success: incompatibility, better option, cuckoldry (CHEATER) 2. CHOICE OF TERRITORY: not the prtner but his house 3. Salvage strategy: accidental loss after migration. 4. forced divorce.

Question 12

Blue tits divorced 59% of the time because of what?

Answer 12

to get a better habitat

Question 13

female black capped chickadee left their partners because?

Answer 13

for a male of higher social rank.

Question 14

species with higher mortality rates have ——– divorce rates

Answer 14

higher

Question 15

High variance in territory or mate quality in the populations leads to ——– divorce rates

Answer 15

higher

Question 16

High quality individuals are —— likely to divorce a bad partner but are —— likely to be divorced.

Answer 16

more/less

Question 17

———– ——– impact divorce rates a lot because it impacts the chance of finding a replacement

Answer 17

environmental factors

Question 18

Black tailed Godwit has migration strategy to arrive when?

Answer 18

when their partner does!

Question 19

Divorce and extra pair copulations allows for what?

Answer 19

Both involve intra-sexual competition for mates and both allow birds to improve their mating status

Question 20

Only –% of socially monogamous species to date are genetically monogamous

Answer 20

14%

Question 21

copulations with individuals other than a mate or social partner is ———

Answer 21

common. 75% of birds

Question 22

why do woodpeckers have no EPC’s in their nests?

Answer 22

the males do most of the incubation and brood pair. She doesnt want to risk the contribution of the male by cheating on him

Question 23

what are the benefits to EPCs?

Answer 23

1. Males increase females 2. Females may gain better genes or gain access to more territory 3. Insurance against infertile sperm from husband

Question 24

wht are the costs to EPCs?

Answer 24

1. Risk of losing care from social mate 2. Risks of parasites and STDs.

Question 25

Monogamy:

Answer 25

an exclusive association with a single member of the opposite sex.

Question 26

Polygamy:

Answer 26

pair bonds with multiple mates of the opposite sex

Question 27

Polygyny:

Answer 27

many females. only 2%

Question 28

Polyandry:

Answer 28

many males. less than 1%

Question 29

Polygynandry:

Answer 29

several females and several males form a communcal breeding unit. <1%

Question 30

Promiscuity:

Answer 30

indiscriminate sexual encounters, usually brief, where both males and females mater with several individuals. 6%

Question 31

Monogamy occurs when:

Answer 31

1. Males cannot monopolize resources necessary for supporting extra mates 2. Male participation increases offspring fitness. Obligate or falcuative

Question 32

Polygyny can evolve when what is abundant?

Answer 32

food, because male care is not needed

Question 33

resource defense polygyny:

Answer 33

males defend resources that females need and females choose males based on male quality and the quality of the resources he defeneds

Question 34

what is the dilemma for females?

Answer 34

be polygynous with a male on a good territory versus by monogamous with a male on a poor territory

Question 35

The difference between territory quality that is sufficient to favour polygyny is known as the what?

Answer 35

polygyny threshold model

Question 36

Can you explain this graph

Answer 36

Polygamy theshold is PT, the minimum difference in quality to favor polygamy. c represent the cost of sharing the resources with other females. Overall female is going to do better by being monogamous

Question 37

what is the mating system of the Lark Buntings?

Answer 37

A male will mate with more than 1 female but assist only the first female to settle on their territory. Some females accept secondary female role on good territories because they still obtain a really good nesting site.

Question 38

what is the mating system of spotted sandpiper?

Answer 38

female spotted sandpipers are 25% larger than males. Female will lay clutches for a primary male and then 1-3 secondary males and only help assist with the last secondary male.

Question 39

what is facultative polyandry:

Answer 39

females become polyandrous if the situation presents itself. Triggered by a biased sex ratio and unpaired males. up to 5% of flickr females are polyandrous and they have greater reproductive success than monogamous

Question 40

some species have multple mating systems that can change depending on ———- ———- and ———- availability

Answer 40

environemtal circumstance/ resource

Question 41

Polygynandry is differet than promiscuity because…

Answer 41

they stick together and help raise them together. Where you have social pair bonds between group members.

Question 42

Acornd woodpeckers have what kind of mating system?

Answer 42

polygynandry