Lecture 9

Question 1

What is a signal?

Answer 1

Implies ‘directed’ communication towards a specific receiver. The sender sends info to the receiver in hopes that the receiver’s behaviour is altered (trying to manipulate behaviour)

Question 2

What are some examples of signals and what does this demonstrate about signals?

Answer 2

Examples: Mating signals, territorial displays, foraging calls
–> The behavioural response of the receiver will provide a benefit to the sender = sender directly benefits

Question 3

What is a cue?

Answer 3

Implies ‘reliable indicator’ of some ecologically relevant information. Examples: Alarm cues, prey location, etc. Does not directly benefit cue sender, they will likely die, but the receiver will gain fitness benefits

Question 4

How do we move from cues to signals?

Answer 4

Secondary selection for novel function: Chemical alarm cues and antipathogen function

Question 5

What are ASCs and what do they do?

Answer 5

alarm substance cells (ASC) → produces damage released alarm cue

Question 6

What did Doug Chibber argue about alarm substance cells (ASC) → produces damage released alarm cue?

Answer 6

Maybe the function of an alarm cue was selected after the cells were already formed. Argued that these cells arose as an antipathogen or antiparasite function

Question 7

What were the 2 experiments that demonstrated that club cells arose as an antipathogen or antiparasite function?

Answer 7

1) Experiment: take a group of minnows and expose them to water, another group of minnows exposed to variable predation risk, and looked at the change in number of club cells (ASCs)
2) Experiment: control or give them different external parasites or internal parasites

Question 8

What were the results of the 2 experiments that demonstrated that club cells arose as an antipathogen or antiparasite function?

Answer 8

1) Exposed to predation: no change in # of club-cells. Exposed to various experiments = no change in # of club-cells
2) Given parasites: density of club cells increases

Question 9

How do club-cells develop the function of alarm cue?

Answer 9

Fish is bitten, releases club-cells and fish smells this and realizes something may be there and swim away → fitness benefit

Question 10

What is the evolution of a true ‘signal’ model proposed by Tristan Wyatt (3 phases)?

Answer 10

1) Pre-Adaptation Phase (Passive Release): This initial phase involves individuals passively releasing chemical compounds (often hormones) into the environment. Individuals exposed to these passively released compounds do not necessarily have any reaction or behavioral response.
2) Spying Phase (Receiver Benefits Fixation): The passive compounds begin to provide a significant cue towards the receivers. Individuals that detect this cue and show a response will gain a benefit without prviding direct benefit to sender.
3) Full Communication (Mutual Benefit): Full proper communication arises when the behavioral response of the receiver now confers a benefit back to the sender.

Question 11

What is an example of full comminucation in Tristan Wyatt’s model of the evolution of a true ‘signal’?

Answer 11

For instance, an individual passively releasing mating pheromones benefits because the receiver changes its courtship behavior. This benefit can then lead to the active release of the compound

Question 12

What is sensory complementarity?

Answer 12

This model suggests that if individuals receive the same message from different sensory inputs, they can gain a better transfer of information. Sensory complementarity allows for additive or even synergistic inputs

Question 13

What did John Alcock’s work demonstrate?

Answer 13

Communication between individuals of a population isn’t always based on a single modality since if animals receive the same message from different sensory inputs, then individuals can gain more information which is critical because it allows individuals to make fine-tuned behavioural decisions!!!!

Question 14

What does the selection favouring sensory modalities depend on? Provide an example.

Answer 14

Selection favouring sensory modalities depends on types of information individuals are detecting and responding to. Ex: Personal info says risky, but social info says not risky.

Question 15

What question does Fred Morton’s work, looking at forest and grassland song birds looked at emphasized frequencies of territorial calls, and the proportion of pure tone, ask?

Answer 15

Does environment shape signal?

Question 16

What are the results of Fred Morton’s work on how the environment shapes signals?

Answer 16

1) High vs low frequency calls: Trends show higher frequencies in grasslands versus forested communities because in forested communities, where predators are hidden, birds don’t want to have high frequency calls that are easily localized. So birds use lower frequencies that will provide information to conspecifics but less directional information to predators.
2) Directionality/Pure Tones: They compensate for the lack of directionality by increasing the proportional pure tones which provides directionality to a conspecific, but also potentially to a predator.

Question 17

Provide a summary of Fred Morton’s work on environment shaping signals?

Answer 17

1) Grassland communities: They use higher frequencies, they utilize fewer pure tones, and the range of frequencies is much greater in grasslands.
2) Forested communities: They use lower frequencies to limit eavesdropping of predators, and to compensate for the lack of directionality provided by these low frequency calls, the birds increase the proportion of pure tones to provide directionality for conspecifics, but possibly for predators as well. Additionally, the range of frequencies is really constrained.

Question 18

How do signals differ in primates due to the environment? (in 2 ways)

Answer 18

1) Spacing Between Troops: Calls used for spacing between troops can be detected at great distances. These calls have a relatively low frequency, which is critical because lower frequencies travel greater distances.
2) Spacing Within Groups and Aggressive Calls: Calls related to spacing within groups and aggressive calls within the group have a much higher frequency. The reasoning is that if an individual is emitting aggressive calls (e.g., “stop it”), they do not necessarily want that sound to travel far

Question 19

What does Lopez Anolis look at?

Answer 19

Does the environment shape the signal of lizard mating pheromones

Question 20

In Lopez’s Anolis lizard mating pheromone experiment, how does the molecular weight of territorial scent marks differ in different environments?

Answer 20

1) Grasslands: smaller chemicals (don’t last as long)
2) Tropical rainforests: larger chemicals (last longer)

Question 21

Why does environment shape the size of chemical compounds as seen in Lopez’s Anolis lizard mating pheromone experiment?

Answer 21

Because grasslands are relatively dry such that chemicals can persist. Compared to the tropical which are extremely damp such that signals will not last long

Question 22

Is there a fitness cost of producing larger vs smaller chemical compounds as seen in Lopez’s Anolis lizard mating pheromone experiment?

Answer 22

YES: greater fitness costs for larger chemicals

Question 23

What are the results of John Kreb’s review on same species in grasslands vs in forests and their calls?

Answer 23

1) Grasslands: They use less of that pure tone, so directionality, and more short punctuated trills. This is because the habitat is open, echoes are minimal, so signals don’t get distorted.
2) Forests: Use longer, more pure-tone, whistled notes with slow frequency modulation. Because forests create echoes and reverberation, rapidly changing or broadband sounds get distorted and pure tones transmit more cleanly through dense vegetation

Question 24

What is a disturbance cue?

Answer 24

Generalized metabolic product likely associated with protein metabolism that is released as a pulse of urine. It is released early-on in the predation sequence (LITERALLY SCARING THE PISS OUT OF FISH).

Question 25

How does the disturbance cue relate to the lima model discussed previously?

Answer 25

Lima model: prey detecting predator first → benefit is that they can release disturbance cues which can lead to altered behaviour

Question 26

How do you collect a disturbance cue or early warning 'signal' as shown in Brian Wisenden's work?

Answer 26

Put a bunch of tadpoles or fish in a tank, then collect (control), then scare them and collect the water (stimulus).

Question 27

What experiment on cichlids's and trouts demonstrates that the Disturbance cue is a Generalized cue?

Answer 27

- Cichlids & trout: collect disturbance cues from both phylogenetically distant species - Cichlids and trout: Cichlids showed a significant response to their own cichlid disturbance cue, but cichlids also responded to rainbow trout disturbance cues. Similarly, rainbow trout respond to cichlid disturbance cues as well as their own.

Question 28

What experiment on guppies and amphibians demonstrates that the Disturbance cue is a Generalized cue?

Answer 28

Guppies and Amphibians: Guppies will respond to the disturbance of tree frog tadpoles. This demonstrates cross-group detection between two dramatically different biologic distant groups

Question 29

What is the Metabolic byproduct hypothesis?

Answer 29

- Joe Kecker's work shows that amphibians are releasing pulses of ammonia as a nitrogenous waste product - In the teleost fishes (bony ray fishes), it is not ammonia (they don't respond to ammonia) but they are releasing pulses of urea as a nitrogenous waste product --> Suggests that we have this cue and it’s released in pulses which can change the behaviour of different individuals

Question 30

Who looked at how diet effects disturbance cues, but only among high risk recievers?

Answer 30

Jack Goldman

Question 31

What was Jack Goldman's experiment looking at the diet effect on disturbance cues?

Answer 31

Take guppies and expose them to high or low background risk and are fed different diets

Question 32

What are the results of Jack Goldman's experiment looking at the diet effect on disturbance cues?

Answer 32

High risk fed with high protein diet, low protein diet, or food deprived: Receivers exposed to high protein cue show greater response

Question 33

What do the results of Jack Goldman's experiment suggest?

Answer 33

This suggests that if you feed them a high protein diet then elicit a disturbance cue, you get a stronger response in comparison to fish fed a lower protein diet. So if you're well fed and you have lots of protein on board, you're producing more of the active component of these disturbance cues.

Question 34

Who looked at how high-risk environments promote chemical disturbance signalling among socially familiar Trinidadian guppies?

Answer 34

Adam L. Crane et al.

Question 35

What was Adam L. Crane et al.'s experiment looking at how high-risk environments promote chemical disturbance signalling among socially familiar Trinidadian guppies?

Answer 35

Trinidadian guppies held in unfamiliar group and familiar group then do a standardized disturbance to collect the disturbance cue to use as a stimulus. LOOKING AT DONOR FAMILIARITY EFFECT!!

Question 36

What were the results of Adam L. Crane et al.'s experiment looking at how high-risk environments promote chemical disturbance signalling among socially familiar Trinidadian guppies?

Answer 36

1) High background risk familiar: increase shoaling 2) High background risk unfamiliar: no change in response (same as control) 3) Low background risk familiar and unfamiliar: Both familiar and unfamiliar individuals produce a disturbance cue

Question 37

Why should unfamiliar individuals be releasing no disturbance cue in high risk conditions, compared to low risk conditions where both release a disturbance cue?

Answer 37

There's a relatively low cost of releasing the disturbance cue in low predation sites

Question 38

Why under high-risk conditions are they not releasing a disturbance cue if they're unfamiliar with those members?

Answer 38

If individuals are in a familiar social group, they are familiar with the response of other individuals and can exert a coordinated response. Previous experiments showed that familiar groups shoal more tightly and more rapidly. However, if the individuals are unfamiliar with each other, they do not know how others are going to respond so releasing the cue to an unfamiliar group is less beneficial because the resulting behavior may not be coordinated, jeopardizing the sender.

Question 39

Who looked at A novel alarm signal in aquatic prey; Familiar minnows coordinate group defences against predators through chemical disturbances cues?

Answer 39

Kevin R. Bairos-Novak et al.

Question 40

What was the experiment performed by Kevin R. Bairos-Novak et al. that looked at how familiar minnows coordinate group defences against predators through chemical disturbances cues?

Answer 40

In fathead minnows, sender can see unfamiliar vs familiar individual and is then the sender is disturbed

Question 41

What are the results of the experiment performed by Kevin R. Bairos-Novak et al. that looked at how familiar minnows coordinate group defences against predators through chemical disturbances cues?

Answer 41

1) Sender sees unfamiliar audience: releases a disturbance cue to likely get them to coordinate behaviour and join the shoal 2) Sender sees familiar audience: releases more disturbance cue

Question 42

What do the results of Kevin R. Bairos-Novak et al.'s paper suggest?

Answer 42

This suggests to use that these are under voluntary control which means the signaler is benefitting

Question 43

What is the Background noise hypothesis?

Answer 43

Release greater concentrations of alarm cues for any response to be elicited in high background noise environments (greater amount of nitrogenous waste)

Question 44

What experiment tested the Background noise hypothesis?

Answer 44

Put groups of fish and add water (control) or add low concentrations of urea, or high concentrations of urea for several days. Then test how much urea is needed to trigger a behavior

Question 45

What are the results of the experiment that tested the Background noise hypothesis?

Answer 45

1) No urea background: Any little amount of urea elicits a response 2) Small amount of urea: takes more urea to elicit a response 3) High urea background: little to no response as they’ve been conditioned to this amount of urea

Question 46

So what do the results of the experiment testing the background noise hypothesis demonstrate?

Answer 46

Different sensory modalities are favoured in high background noise environments. The environment shapes how they communicate and how they respond. For example, the response to chemosecondary cues is greater in juvenile salmon at night because they cannot see the predator

Question 47

What is an example of how The environment shapes how they communicate and how they respond?

Answer 47

The response to chemosecondary cues is greater in juvenile salmon at night because they cannot see the predator

Question 48

Who looked at Simultaneous cues- risk & social safety?

Answer 48

Adapted from Feyten et al. 2021, Behav Ecol

Question 49

What is the experiment performed by Adapted from Feyten et al. 2021, Behav Ecol on Simultaneous cues- risk & social safety?

Answer 49

Looking at wild-guppies in streams and whether or not they will enter in a novel foraging arena, there’s a piece of airline tubing stuck in the back to allow for introduction of chemical cues, and there’s a bottle in the arena with either a group of conspecific female guppies or its empty. High risk or low risk pop with presence or absence of social info. Record how long it takes for individuals to enter a novel foraging patch and the rate of foraging.

Question 50

What are the 3 predictions of Feyten et al. 2021, Behav Ecol's paper on Simultaneous cues- risk & social safety?

Answer 50

1) High predation: avoidance of novel cue 2) High predation will be more cautious 3) Difference in response when we add social safety information

Question 51

What are the results of the experiment performed by Adapted from Feyten et al. 2021, Behav Ecol on Simultaneous cues- risk & social safety?

Answer 51

1) High predation population: Give alarm cue, take a long time to enter, and give novel odor and take a long time to enter in absence of social info. When given social info, the neophobic response to the novel odour disappears, but they still respond to alarm cues. 2) Low predation population: If there’s no shoal present (social info) individuals take longer to enter a risky patch when they get an alarm cue and novel cue. When there’s a shoal present, the response to the alarm cue disappears. They no longer use their personal info and only rely on social information. --> Social safety mediates response to reliable personal risk cues in low-risk sites!

Question 52

Why is there a loss in response to the alarm cue in a low predation population?

Answer 52

Risk allocation hypothesis: predicts this response because the cost of not responding is relatively low, bc predation is rare and infrequent. However, in high predation, predation is common so the cost of not responding is high since they’re more likely to be preyed upon.

Question 53

What is the difference in response to novel odour in high predation sites when there’s no shoal vs when there’s a shoal?

Answer 53

Error management: High predation populations will err-on the side of caution without social info because they’re uncertain. When there’s a shoal present, then there’s less uncertainty so they will not respond → behavioural decisions are based on multiple sources of information

Question 54

What is the 1st experiment that looks at different types of information (sensory complementarity) and uncertainty?

Answer 54

Large maze with a container with a single fish in the middle. Week before, everyday for 5 mins, put a fish in the bottle and then expose it to a predator model (risky cue) or give the fish food (a safety cue).

Question 55

What are the results of the 1st experiment that looks at different types of information (sensory complementarity) and uncertainty?

Answer 55

1) Predator everyday: Significantly less movement since they learned that the arena is risky. 2) Food everyday: food everyday then allows them to explore the maze without social info, they will explore a lot.

Question 56

What is the 2nd experiment that looks at different types of information (sensory complementarity) and uncertainty?

Answer 56

Give them in random order, predator model or foraging cue (randomized risk and safety)

Question 57

What are the results of the 2nd experiment that looks at different types of information (sensory complementarity) and uncertainty?

Answer 57

Initial exposure, no movement from the fish due to uncertainty. An hour or 2 later, they increase activity. Field data suggests that over long periods of exposure: increase in activity

Question 58

What is a form of Exploitation of information?

Answer 58

Eavesdropping

Question 59

What is Eavesdropping?

Answer 59

Eavesdropping: use of broadcast signal by unintended receiver

Question 60

What are 6 examples of eavesdropping?

Answer 60

1) Egg dumping in fishes: sex pheromones as eavesdropping cues 2) Territorial markers: antelope and ticks 3) ‘Cooperative’ foraging: coyotes and corvids 4) Intersexual eavesdropping and mate choice copying 5) Predator foraging cues → pike cichlids 6) Sex pheromones as eavesdropping cues

Question 61

Explain how Egg dumping in fishes = sex pheromones as eavesdropping cues?

Answer 61

Mouth brooding cichlid male takes incubates eggs and then male releases eggs upon hatching. Ictalurid catfish male deposits eggs near breeding cichlids so that the cichlid male takes up the developing eggs. Catfish use cichlid mating pheromones as a cue!

Question 62

Explain the example of eavesdropping: Territorial markers: antelope and ticks.

Answer 62

Ticks use auditory and visual cues of antelope to climb higher on grass stalks such that they hang onto the antelope when they walk by.

Question 63

Explain the example of eavesdropping in ‘Cooperative’ foraging: coyotes and corvids?

Answer 63

In the winter, dead deer are frozen solid, so the corvids circle the carcass to signal to coyotes that there is food and then the coyotes rip through the flesh which corvids now have access to.

Question 64

Who wrote the paper, "Visual and chemical prey cues as complementary predator attractants in a tropical stream fish assemblage"?

Answer 64

Chris K. Elvidge & Grant E. Brown (2012)

Question 65

What is the experiment performed by Chris K. Elvidge & Grant E. Brown (2012) in their paper "Visual and chemical prey cues as complementary predator attractants in a tropical stream fish assemblage"?

Answer 65

Guppy in a bottle experiment with 3 common predators of guppies paired with water control or alarm cue from a rivulus

Question 66

What are the results of the experiment performed by Chris K. Elvidge & Grant E. Brown (2012) in their paper "Visual and chemical prey cues as complementary predator attractants in a tropical stream fish assemblage"?

Answer 66

1) Pike Cichlids: Responds primarily to visual cues 2) Blue acara: Responds to both visual and chemical cue 3) Sardines: Responds to chemical cue

Question 67

What do the results of the experiment performed by Chris K. Elvidge & Grant E. Brown (2012) demonstrate?

Answer 67

Eavesdropping can cross different levels: Predators themselves are communicating and responding in that if you look at a stream section with different predators present, when you see a pike cichlid active, you won’t see the others active. The blue acaras and sardines are only active in the absence of the pike cichlids. They use info from competitor predators and from prey to adjust their behaviors

Question 68

What is the experiment performed in order to look at the manipulation of eavesdropping and mate choice copying in canaries?

Answer 68

Working with canaries. Looked at experienced females vs virgin females in response to overlapping calls from males and other males in temporal proximity.

Question 69

What are the results of the experiment performed in order to look at the manipulation of eavesdropping and mate choice copying in canaries?

Answer 69

1) Experienced females: there's no difference between the displays females are giving towards overlapping versus other calls of males 2) Virgin females (unmated): They are far more likely to pay attention to the overlapping male compared to the other males that are calling and not getting attention. They are more likely to direct courtship displays toward the overlapping caller.

Question 70

What do the results of the canary experiment, performed in order to look at the manipulation of eavesdropping and mate choice copying in canaries, demonstrate?

Answer 70

Males can manipulate their signaling behavior in response to females engaging in eavesdropping (or mate choice copying), primarily through the example of canaries. Specifically, experiments with canaries showed that males can exploit the calling efforts of other males, resulting in a "double whammy of eavesdropping" where both females and males are utilizing information

Question 71

Is there a cost to this the eavesdropping seen in male canaries?

Answer 71

Calling is energetically expensive, time-consuming, and increases visibility to predators for the male doing the initial effort. Therefore, the exploiting male can wait until females show signs of choice and then make just "one little chirp" or a few calls over top, effectively letting the other males do the work of attracting females while the overlapping caller reaps the benefits.

Question 72

Who gains the energetic benefit in the example of the manipulation of eavesdropping in male canaries?

Answer 72

The male who called initially was invariably the loser and did not get the courtship displays from the female, while the male who slightly delayed and overlapped the other's call was the winner and received the courtship display. This energetic benefit likely translates to a fitness benefit

Question 73

Who looked at the effects of eavesdropping on subsequent signalling behaviours in male canaries (Follow-up experiment to the manipulation of eavesdropping in canary males)?

Answer 73

Mathieu Amy and Gerard Leboucher

Question 74

What was the follow-up experiment performed by Mathieu Amy and Gerard Leboucher looking at the effects of eavesdropping on subsequent signalling behaviours in male canaries?

Answer 74

Observing the order of signaling behaviors in a wild population in order to determine the cost associated with the male calling behavior

Question 75

What was the control in the follow-up experiment performed by Mathieu Amy and Gerard Leboucher looking at the effects of eavesdropping on subsequent signalling behaviours in male canaries?

Answer 75

Control Conditions (Alternating and succession): 1) In the alternating condition (where calls were not overlapped), there was no difference in the effort between the two birds, and they had to make a lot of calls, indicating a lot of energy associated with calling. 2) In the succession condition, the reduction in calls for the second bird was not statistically significant

Question 76

What were the results of the follow-up experiment performed by Mathieu Amy and Gerard Leboucher looking at the effects of eavesdropping on subsequent signalling behaviours in male canaries?

Answer 76

1) Close Temporal Proximity (Overlapping Calls): Males were calling, and a second male (the overlapping caller) delayed slightly and called over top of the initial caller 2) Alternating Conditions (Temporally Separated): Birds were calling under natural conditions, but their calls were not temporally overlapped (e.g., one bird calls, and a few minutes later, a different bird calls) 3) Succession: One bird is calling, and then sometime later a different bird is calling

Question 77

What do the results of the follow-up experiment performed by Mathieu Amy and Gerard Leboucher looking at the effects of eavesdropping on subsequent signalling behaviours in male canaries, confirm?

Answer 77

Results confirmed that there’s a huge energetic benefit for the male that manipulated the signaling order, demonstrating that this behavior is an example of "eavesdropping times two". This is shown as the male doing the initial calling effort was invariably the loser and did not receive the courtship displays from the female. Whereas, the male that delayed slightly and overlapped the call of the first male was the winner meaning they received the courtship display from the females.

Question 78

What is eveasdropping x2?

Answer 78

Example of eavesdropping x2: females are eavesdropping (mate-choice copying), but males are also eavesdropping by overlapping their calls such that they gain an energetic benefit