5. Animal Communication

Question 1

What is communication?

Answer 1

Specially designed signals to modify the behaviour of others

Question 2

What is a cue?

Answer 2

a feature used by the receiver, but did not evolve for that purpose -e.g. leaf rustling of a mouse

Question 3

What is a signal?

Answer 3

acts or structures that alter the behaviour of the receiver

have evolved for that purpose - e.g. bird call or peacock tail

Question 4

What are some common functions of signals?

Answer 4

Recognition
Advertise unpalatability
Advertise quality
Establish and defend territories
Alert others
Give foraging information
Advertise need

Question 5

Why is recognition important?

Answer 5

Species recognition - May help to avoid maladaptive hybridisation
Kin recognition - facilitate outbreeding & allow helpers to recognise kin

Question 6

What kind of colouration advertises unpalatability to predators?

Answer 6

Aposematic

Question 7

Aposematic colouration tells predators what?

Answer 7

That the prey is unpalatable

Question 8

What benefits can advertising quality have?

Answer 8

Attracting mates or detering competitors

Question 9

What type of signals can advertise ownership of territory?

Answer 9

Scent posts, marking, songs

Question 10

Alarm signal can be diverse, which two examples are the best?

Answer 10

Vervet monkeys - vocalisations

Social insects - chemical signals

Question 11

Aside from the honey bee waggle dance, which other animal is known for conveying foraging behaviour? (and reference)

Answer 11

Pied Babbler - ‘purr’ calls to recruit foragers to rich food patch
Radford and Ridley 2006

Question 12

What ways of conveying need do offspring employ?

Answer 12

Gape, Posture, Vocalisations, Tactile Stimulation

Question 13

In order for signals to evolve they must be …

Answer 13

1) Detectable to the receiver

2) Of minimal cost to the signaller

Question 14

What traits make signals more detectable?

Answer 14

Conspicuousness
Alerting components
Redundancy - repetative and predictable
Stereotypical - standardised

Question 15

What factors can affect the efficacy of a signal? (or increase selection pressures)

Answer 15

Physical environment

Audience

Question 16

There are four types of signal, what are they?

Answer 16

Chemical
Tactile
Auditory
Visual

Question 17

Cooperative signalling is what?

Answer 17

When both the signaller and the receiver benefit from the response.

Question 18

What situations may elicit cooperative signalling?

Answer 18

Honey be waggle dance - the colony benefits from having more food available
Species recognition - both benefit from mating with the right species
Calling individuals to your food source - may benefit from feeding in groups

Question 19

When may signals become costly for the receiver?

Answer 19

Offspring - signal that they are hungrier than they are (parent-offspring conflict)
Males - signal that they are of better quality than they are

Question 20

Which signals did Maynard-

Smith 1974 say would quickly become meaningless?

Answer 20

Dis-honest/deceitful

Question 21

How can biological signals maintain honesty?

Answer 21

Physical constraints on deceit

The handicap principle

Question 22

How are signals bound by physical constraints on deceit?

Answer 22

The signals will be very hard to fake if they are functionally tied to the physiological quality of the individual
e.g. body size and croaking

Question 23

What is Zahavi’s 1975 handicap principle?

Answer 23

If signals are costly to produce, they are more likely to be honest.
Only superior individuals will have the capacity to succeed/produce.

Question 24

The handicap principle was proposed by who, when?

Answer 24

Zahavi 1975

Question 25

What does the magnitude of signals indicate?

Answer 25

The receivers do not register signals of low magnitude as they may not be true signals. - Could be a point of conflict.

Question 26

What does parasite resistance have to do with male signalling?

Answer 26

Hamilton & Zuk (1982) suggested that the males with more extravagant displays are more resistant to parasite, and that parasite displays are heritable.
Females may be choosing males due to their parasite resitance

Question 27

How to parasites generate variation in quality?

Answer 27

Parasites evolve 1000x faster than host therefore hosts can never all be high quality - females can constantly select for higher quality males with fewer parasites
Parasites enable the signal to always be honest

Question 28

If signals are not energetically costly, can they be honest?

Answer 28

Yes - they could be socially costly. Others may punish the cheater

Question 29

Can deceitful signals continue?

Answer 29

Yes - they will continue until the cost of being deceived outweighs the benefits of responding.

Question 30

What two things will signal evolution be determined by?

Answer 30

Efficacy based components - selection pressures on the signaller to ensure signals are efficient
Strategic components - selection pressures on the receiver to ensure the possibility of deceit is minimal