L4

Question 1

Hornet clearwing moth example of deceptive communication

Answer 1

• Evolved to look like a wasp
• Puts off a potential predator

Question 2

Sexual Deception in Bluegill sunfish

Answer 2

• Looks like a female fish but is a male
  -Other male thinks male is a female
  -Male therefore copulates with females in the other males territory stealing copulations

Question 3

Bolas spider

Answer 3

• Attracts male moths by mimicking the female moths pheromone
  
  • Male is attracted and then spider attaches bolas to moth
  • Exploits sexual communication in a different specie

Question 4

What species uses sexual deception across species?

Answer 4

Bolas spider

Question 5

Why haven’t moth evolved to avoid this attraction to (Bolas spider)

Answer 5

• Mimics are relatively rare
• Majority of the time pheromone attraction will lead to successful mating
• Unfortunate to be sexually deceived

Question 6

Sexual selection definition

Answer 6

• Female choice selects for male traits that persuade females to mate with them… this leads to a co-evolutionary arms race between the sexes

Question 7

What three ways do animals signal communication is honest/ reliable?

Answer 7

Common interests

Handicap/cost

Index of quality (uncheatable signals)

Question 8

Common interests

Answer 8

• Signaller and receiver both benefit from relayed information

Question 9

Index of quality (uncheatable signals)

Answer 9

• Cannot be falsified
• Larger individuals can produce deeper sounds

Question 10

Honest communication due to common interests: Honeybees

Answer 10

• Helps out relatives and gene flow

Question 11

Raven Yelling, can they be honest if individuals are not related?

Answer 11

• Carcasses are a valuable resource to a raven
  
  • How did the raven inform other ravens of food presence? Why would they reduce a resource like this by sharing?

Question 12

Hypotheses 1 for the adaptive significance of yelling

Answer 12

• They attract a carcass opener eg bear and incidentally more ravens come

Question 13

Against the adaptive yelling hypothesis 1

Answer 13

• Lone ravens finding a carcass often did not yell
  -Ravens at an opened carcass did sometimes yell

Question 14

Hypotheses 2 for the adaptive significance of yelling

Answer 14

Selfish herding: attract more ravens in case of a predator attack

Question 15

Against the adaptive yelling hypothesis 2

Answer 15

-Lone ravens finding a carcass often did not yell
- Yelling continued at carcasses with many ravens

Question 16

Hypotheses 3 for the adaptive significance of yelling

Answer 16

Overwhelm defence of territory holding ravens

Question 17

Hypothesis 3 results

Answer 17

• Correct hypothesis
• Territory holding ravens did not yell when they found a carcass
• Non-resident ravens yelled

Question 18

What is the benefit of raven yelling?

Answer 18

• Non-resident yells to attract and overwhelm resident raven
  
  • Honest communication favoured by common interests

Question 19

Handicap/ cost - Why do chicks beg?

Answer 19

• parents often give more food to chicks that beg more
  
  • Costly for chicks to beg

Question 20

Why feed chicks who beg more?

Answer 20

Hungry chicks get a large increase in survival for a certain amount of food whereas well fed chicks receive a small increase in survival for the same amount of food

Question 21

Why is begging an honest signal?

Answer 21

• There is a cost associated with begging behaviour
• Only hungry chicks will beg, less hungry ones shall not

Question 22

One cost of begging?

Answer 22

Nest predation

• if one begs loudly there is a chance they will eat all bird chicks

Question 23

Black- throated warbler

Answer 23

• Tree nesting species more protected so can beg louder
  
  • Attracts more predators than the begging of ground nesters

Question 24

Tree nesting species on the ground

Answer 24

• High frequencies don’t travel as far
  
  • Ground nesting birds have adapted to beg with calls that don’t travel as far (higher frequencies)

Question 25

Costs to chick from begging more

Answer 25

• Chick begging is linear
  
  • More the chick begs the more food it shall get
  • Optimal begging intensity
  • Point where cost and benefit are furthest apart
  • Optimal begging produced

Question 26

Is begging intensity lower or higher in chicks that have been fed slightly?

Answer 26

Lower

Question 27

Lowering predation risk

Answer 27

• Tree nesting birds have a lower cost
  
  • Reducing cost increases optimal level of begging

Question 28

Begging and relatedness

Answer 28

Eg extra pair parentage and extra pair paternity

Show a positive correlation between these two factors and begging loudness

Question 29

Are chicks closely related more or less likely to beg?

Answer 29

Chicks closely related to each other less likely to beg as don’t want to kill themselves or kin

Question 30

High quality males

Answer 30

• Invests in an elaborate display which is costly
  -Assume this reduces survival

Question 31

Low quality males displaying

Answer 31

• Less resources for display so is more costly than it is to high quality males
  
  • Say a plumage doubles chances of mating
  • Overall benefit

Question 32

Male quality and displaying

Answer 32

High quality males Benefit increases more than it does in low quality males

Low quality males better off not displaying

Question 33

Index of quality (uncheatable signals)

Answer 33

• Honest due to uncheatability: toad calls
• Larger males have a deeper call

Low frequency calls deterred males more than high frequency calls

Question 34

Cheating body size

Answer 34

• Possible up to a point
  
  • Inflating abdomen
  • Puffing out chest
  • Making hair stand on end
    Elongating larynx to make deeper call

Some uncheatable signals are somewhat cheatable