1
Q
Game Theory
A
- An evolutionary approach to the study of adaptive value in which payoffs to individuals associated with one behavioral tactic are dependent upon what the other members of the group are doing
2
Q
Ideal Free Distribution (IFD)
A
- The distribution of individuals in space that are free to choose where to go in ways that could maximize their fitness
- Individuals should always select the best habitat available
- As more individuals enter habitat quality decreases due to competition for resources
- All individuals have equally reduced quality habitats
- Resources available in each patch are always equal to R/N where..
- > R = # of resources in each patch
- > N = # of individuals in each patch
- > Eventually the value of each patch becomes equal to one another
3
Q
Why do so few animals forage optimally?
A
- usually assume predation risk, patch value and starvation risk are all constants which are not true in the wild
- > Methods will switch given the change in energy reserves, or since you have been last fed
- Risk Sensitive Model shows they will not forage optimally as well
- > because the optimal foraging models assume that everyone is at the same risk of starvation and that is not always true
- Predation-Foraging Trade-off shows they will not forage optimally as well
- > there are also other risks of foraging such as predation
- > assumes that patch value is a constant
- > predation risk is a constant
4
Q
Predation Risk Model: Escaping Attacks
A
- Startle coloration
- Bright flash patches
eyespots - Evasive maneuvers
- Group behaviors
- Vigilance
- Confusion effect
- Mobbing
5
Q
Vertical Waggle Dance Problem Rules
A
- Top = 0
- Bottom = 180
- Sun is always at the top
- Measure clockwise from top
- Top is N, Bottom S Right is E and Left W
- Arrows are vectors and indicate the direction of the waggle dance
- CAN NOT use times it is only the distance between the flower and sun
6
Q
Anti-predatory Behaviors Methods
A
- Evolutionary Arms Race
- Predation Risk Model
- Spiny Lobster Adaptations
7
Q
Situation
A
- a given set of conditions at one point in time
- Different situations could involve different levels along an environmental gradient (different levels of predation risk) or different sets of conditions across time (the breeding season versus the non-breeding season)
8
Q
Categories of Communication: Sexual Intraspecific
A
- Specificity = High
- Elements = Many
- Deception = Low
9
Q
Economic Defendability
A
- When should an individual defend a territory vs. share a territory?
- > When the benefits of extra resources is greater than the cost of territory defense
10
Q
Evolutionary Arms Race
A
- Predators and prey co-evolve adaptations for prey capture and predator avoidance due to their strong evolutionary influence on one another
- > Predators and prey are trying to outdue one another in terms of an optimal strategy
- > Predators are selected for improving foraging and prey are selected for improving defenses
- Red Queen Hypothesis
11
Q
In an Evolutionary Arms Race what traits do predators acquire?
A
- Visual acuity
- Search image
- Search patterns
- Learning ability
- Speed
- Offensive weapons
- Detoxins
12
Q
What is the one assumption that differs between the ideal free and ideal despotic distributions?
A
- In the IFD, Competitors are equal in all respects
- Whereas in the IDD, Competitors are unequal in their ability to exploit resources
13
Q
Habitat Preferences, or how do individuals come to recognize suitable habitats?
A
- Innate settlement cues
- > Environmental cues for example Conch use red algae
- > Reef fish use sounds of waves breaking on the reef - Learn cues from natal habitat
- Butterflies
- Salmon
- Arctic terns - Use conspecifics as settlement cue
- Barnacles
- Lizards
- Song birds
14
Q
Ritualization
A
- The evolutionary process whereby a convenient behavior, anatomic structure, or physiological change becomes molded into a useful signal.
- The original trait is modified by changing either the rate, intensity, orientation, or rhythm of performance until the evolved signal is produced independently from the original trait from which the signal evolved.
15
Q
Landscape Projection Problem Rules
A
- Rules
1. South = 180 - always on top
2. North = 0 - always on bottom
3. East = 90 - always on left
4. West = 270 - always on right
5. Sun moves at 15 degrees/hr - in a clockwise projection
6. Sun always rises at 6 am (0600) and sets at 6 pm (1800) - > sun rises in the east at 90 degrees
- > whatever time is given find the difference of hours passed since 6 am
8. SE is halfway between S and E = 135 degrees
16
Q
Predation Risk Model: Avoiding Detection
A
- Coloration
- Disruptive coloration
- Cryptic
- Polymorphism - Distribution and spacing
- Cryptic behavior
- Remaining motionless
- Swaying rhythmically
17
Q
Predictions of The General Theory of Play
A
- Those individuals with more play experience should do better in loss of control situations
- Dominant individuals should allow subordinates to defeat them during play bouts
- Play behaviors should activate the somatosensory, motor and emotional regions of the brain
- Play should be most common in species that experience the most variable environment
18
Q
Personality
A
- A consistent long-term phenotypic behavioral response of an individual across different situations
- > Behavioral type, or behavioral phenotype
- > Coping styles
- > Personality
- Opposite of behavioral plasticity
- > The ability of an organism to behave differently depending on the environmental conditions
19
Q
In the Prey Selection Model what size prey items should be selected to maximize the net rate of energy intake?
A
- Assumption is that prey items of different sizes will have different profitabilities
- > energy gained / energy expended
- Prediction is that optimal foragers should select prey that maximize their net energy intake
- Another Prediction is that optimal foragers should be choosy about the size of prey they select
20
Q
Coping Style
A
- A set of behavioral and related stress responses that are consistent over time
21
Q
Diet Selection Model Generalist vs Specialist
A
- Answers the question of which prey types should be included in an optimal diet to maximize the net rate of energy intake?
- Important in herbivores because they eat a variety of different plants, etc
- Generalist and Specialist
-> Specialist feeds primarily on a single prey item
-> Generalist feeds more broadly on prey items available - This model tries to predict when you bring more than one item into your diet
-> Aka when is it better to be a generalist vs a specialist?
Ex: If the specialist equation is higher than the generalist equation than the animal should be a specialist and eat one prey item instead of being a generalist and including two or more prey items in their diet and vice versa if generalist equation is higher
22
Q
Spiny Lobster Adaptations for Antipredatory Behavior: How do spiny lobsters reduce predation risk? Is gregariousness an adaptation to reduce predation risk? Which level of the predation process (encounter, detection, capture) does the gregarious behavior of spiny lobsters most likely confer an advantage?
A
- How do spiny lobsters reduce predation risk?
1. Avoid Encounters - emerge from shelters only at night and hide during the day
2. Avoid Detection - transparent, or clear
3. Discourage Attacks - giant spines
4. Escaping Attacks - group defense
5. Avoiding Consumption - shell, spine and will even become aggressive towards conspecifics
- Is gregariousness an adaptation to reduce predation risk?
- > NO, aggregate ONLY because they use the odors to locate limited shelters and when attacked every man for himself
- Which level of the predation process (encounter, detection, capture) does the gregarious behavior of spiny lobsters most likely confer an advantage?
- > Gregariousness begins
1. When crypsis ends
2. When seeking crevice shelters
3. Before group defense is effective - Gregariousness is:
1. Favored by reducing encounters*
2. Not favored by escaping attacks
3. May be decreasing in lobsters today
23
Q
Evolution of Communication: Handicaps
A
- Handicaps are honest signals because they are costly to produce
- Low quality males cannot afford to produce these high cost signals, but high quality males can.
Ex: - If the benefit (B) of producing a costly ornament is equal for all males…
- And the cost (C) of producing the ornament is less in high quality males than in low quality males…
-> The signal is a reliable indicator of male quality because only high quality males are selected to produce the signal
24
Q
Many eyes hypothesis
A
- Safety in numbers that comes from an increased probability of detecting a predator’s approach by a group of vigilant prey.
25
Red Queen Hypothesis
- change the way animals look, behave and respond to risk
- An evolutionary hypothesis which proposes that organisms must constantly adapt to survive while pitted against ever-evolving opposing organisms in an ever-changing environment
26
Ideal Despotic Distribution (IDD)
- The distribution of individuals in space where those that arrive first, or have the highest RHP take the highest quality territories excluding others
- First individuals in a territory defend the resources and excluding others from using the territory
- > Therefore, later individuals must accept lower quality territories and less resources
- Resources available in each patch are always equal to R/N where..
- > R = # of resources in each patch
- > N = # of individuals in each patch
- > However patches are never shared
- > Thus, patch values are usually never equal
27
Predation Foraging Trade-off
- Foragers should forage optimally so long as it does not result in higher risk of predation
- When predators are present, alternative foraging strategies that minimize predation risk are favored
-> trade off foraging optimization for safety
Ex:
- Sticklebacks choose high prey density when predator is absent
- But, Sticklebacks choose low prey density when predator is present because it is easier to watch for predators
28
Illegitimate signaler
- An individual that produces signals that may deceive others into responding in ways that reduce the fitness of the receiver.
29
Illegitimate receiver
- An individual that responds to the signals of others, thereby gaining information that it uses to reduce the fitness of the signaler.
30
Ecological Traps, or what if the cues that used to indicate quality habitat no longer do so?
- in an environment that has been altered suddenly by human activities, an organism makes a maladaptive habitat choice based on formerly reliable environmental cues, despite the availability of higher quality habitat
- > An ecological trap is a specific type of evolutionary trap
- Historically, cues (A,B,C) indicate high quality habitat
- > But due to rapid degradation of habitat cues (A,B,C), they are no longer associated with quality habitat
- When habitat preference is high, but habitat quality is low ecological trap
- Conservation biologists might solve this problem by improving habitat or introducing the proper cue
31
Acquisition of Play
1. Hormones mediate play
- Testosterone stimulates play fighting behaviors
- Dopamine prepares the brain for play bouts
2. Neural centers for play
- Parafascicular area (PFA) is involved as is the fosC gene.
32
Evolution of Communication: Indices
- Indices are honest signals because their production is limited by physical attributes that cannot be faked.
- Sequential assessments make for good indices.
- ritualized contest
Ex Body size
- Usually size determines how many assessments are needed to determine a winner.
- Big size differences are usually determined by tail beating.
- Small size difference usually lead through all four assessments and is determined by circling.
Ex Frog Calls
- The frequency of a frog call is proportional to its size
- The decision to try and displace a mating male frog was shown to be influenced by whether the call was high or deep.
- However, large males were still challenged less than small males.
Ex Elk Bugle
- Frequency of an elk bugle is proportional to body size
- Thus, the bugle can signal size and predict reproductive success
33
Energy Maximizer
- An individual that maximizes the rate of energy gained per unit time by choosing prey (or patches) with the highest net energy gain (Eg – Eh).
34
Producer-Scrounger Model
- Mixed strategy
- Producer strategy
- > Always seeks food by active hunting
- Scrounger strategy
- > Always steal food discovered by others
- Both strategies fitness declines with density
- ESS is the proportion of scroungers where producer and scrounger fitness is equal
35
Tungara Frogs and Mating Communication Methods
- Tungara frogs sometimes add extra syllables to their advertisement calls
- Extra syllables are more attractive to females.
- Extra syllables are also more attractive to bat predators.
- > The solution for males is to make extra chucks only when they are in large choruses and are harder to pick out by bat predators.
36
Fox Farm Experiment; Genomic Explanation and Conclusions
- Genomics
- > Tame personality is due to higher levels of serotonin receptors in the brain
- > Down regulation of the HPA axis
- > Lower CORT levels
- > "Went" gene signaling in the neurocrest cells slow development
- > Pedimorphic appearance, such as floppy ears, star markings, and curly tail
- Conclusions
- > Selection for tame personality leads to many changes in appearance and behaviors due to linked genes
- > Understanding which genes are associated with different personalities help us to treat behavioral disorders in animals and humans
37
Evolutionary Stable Strategies (ESS)
- A genetically distinctive set of rules for behavior that when adopted by a certain proportion of the population cannot be replaced by any alternative strategy
- the idea that an individuals behavioral decision depends on what the entire population is doing
- > Therefore, the pay-off for performing a behavior may depend on what others are doing in the same population
- Nash equilibrium
- > First described by John Nash (Princeton)
- > Discovery was the subject of the movie “A Beautiful Mind”
- A strategy which when adopted by most members of a population cannot be beaten by any other strategy in the game.
38
Play Definition
- All motor activity performed postnatally that appears to be purposeless, in which motor patterns from other contexts may often be used in modified forms and altered temporal sequencing.
39
Predation Risk Model: Avoiding Consumption
1. Defensive structures
- Spines and stings
2. Defensive behaviors
3. Autonomization and bites
4. Chemical weapons
- sprays and toxins
40
Types of Play
1. Object Play
- Use of an object beyond that of trying to determine what the object is
2. Locomotor Play
- Rapid sequencing of seemly random elements of movement involving widely different speeds and postures
3. Social Play
- Coordination of behavioral elements with one or more partners that involve ”play markers” to signal intent and conciliatory gestures
41
Honeybee Waggle Dance Communication
- Honeybee workers have a common interest to tell others where to find food
- This is communicated with a display called a “waggle dance”
- Round dance
- > Indicates food is near the hive
- > No direction info
- Waggle Dance
- > Indicates food is distant from hive
- > Direction Info
- > Distance Info
- On a flat surface, the waggle direction points toward the nectar source
- On a vertical surface, the waggle direction relative to vertical is the same angle from the azimuth of the sun to the nectar source
- Newly recruited foragers arrive at the right angle and the right distance and then find the nectar source by sense of smell
42
What factors contribute the most to wolf pack territory size and pack longevity? Is the Gray Wolves pack size optimized for efficient hunting or for efficient territory defense?
- Pack size varies with:
1. Age range of the members
2. Proximity to the next pack
3. Number of prey in territory
- Pack longevity varies with:
1. Age (experience) of leaders
2. Stability of social structure
3. Pack size
- Pack success varies with:
1. Number of offspring that survive
2. Ability to hold territory across generations
3. Ability to defend borders from rival packs
- > Pack longevity is positively related to pack size rather than location of territory or availability of prey
- -> therefore pack size is not optimized for efficient hunting or territory defense
43
Deception
- Exchange of information that is beneficial to the sender but harmful to the receiver.
44
Channel of Communication: Visual
1. Range = Medium
2. Change = Variable
3. Obstacle = Poor
4. Locate = Easy
5. Cost = Variable
45
Search image
- As foragers (or predators) encounter potential food items (or prey), they develop an enhanced ability to recognize those items in the future when they are foraging (or hunting).
46
Predator Risk Effects Arise when
- Most of the time prey are not eaten by predators, therefore animals are living under the threat of predation (Risk effects) which alter their behavior
- Predators alter the behavior of prey and this negatively influences the fitness of the prey
-> Indirect effect of predators on prey in which they alter the behavior of prey in a negative way
Negative Consequences:
- Anti-predatory responses can reduce either survival or reproduction
- Risk effects can exceed direct predation effects
-> Risk effects can have larger negative consequences than direct predation effects
-> it could even have an effect on other animals in the community
- Whether prey should minimize direct predation or risk effects depends on their relationship
-> depends on the preys strategy
47
Channel of Communication: Chemical
1. Range = Long
2. Change = Slow
3. Obstacle = Good
4. Locate = Difficult
5. Cost = Low
48
Categories of Communication: Interspecific
1. Specificity = Low
2. Elements = Very few
3. Deception = High
49
Game-Theory Modes
1. Hawk-Dove Aggression Model
| 2. Producer-Scrounger Foraging Model
50
Assumptions of the Diet Selection Model
1. Searching and handling are mutually exclusive activities
2. Encounter with prey is sequential and random
3. E (net energy from prey i), h(handling time of prey i), lambda (prey encounter rate #/time) remains constant
4. Forager has complete information of all these assumptions
- cant forage optionally unless they know these assumptions to make these decisions
51
Ecology of Communication: Type of Information
1. Knowledge
- personal information
- observations
- personally acquired
- Information about physical habitat, resource availability, number of competitors
2. Public Information
- Social Information
- Cues
- Inadvertently Acquired
- Information about location of resources or the quality of resources based on the presence of others
3. Communication
- Social Information
- Signals
- Intentionally Acquired
- Information shared with others that due to natural selection contains honest information regarding one’s state, intentions, size qualities, or abilities
52
Channel of Communication: Auditory
1. Range = Long
2. Change = Fast
3. Obstacle = Good
4. Locate = Variable
5. Cost = High
53
Evolution of Communication: Signal Reliability
- Communication is an evolutionary arms race where senders try to manipulate receivers and receivers try to mind-read senders.
- If senders manipulate receivers too well, then receivers will be favored to ignore senders.
- So signals must carry information of interest to the receiver that convey a benefit on average.
- So what maintains the honesty of these signals?
- > indices
- > handicaps
54
Marginal Value Theorum
- A rate-maximizing forager will choose the residence time for each patch type so that the marginal rate of gain at the time of leaving equals the long term average rate of energy intake in the habitat
- > rate maximizing forager is going to get the most energy per unit time
- > Will choose a residence time in a patch
- -> Assumes that patches become depleted the longer you feed in a particular patch
- -> so if this is the only patch you are going to visit you should stay until the patch is starting to get depleted, not when all of the max resources is found and find a new one
- Efficiency of energy gain in a patch is determined by how far the new patch is
- > make a decision based on how much resources you can use vs the time it takes to get to the next patch
- > if you have to take longer to get to the next patch you will stay longer and vice versa if the distance is shorter
55
Predation Risk Model: Discouraging Attacks
1. Coloration
- Aposematic coloration
- Batesian mimicry
2. Advertising Unprofitability
- Stotting
- Inspection visits
- Why be brightly Colored?
- > bright colors are easier to learn
- Why be toxic?
- > Increased chance of survival if grabbed
- > better able to learn to avoid non-cryptic food
3. Group behaviors can discourage predators by:
- Increasing your apparent size
- Disguising your true identity
4. Individual behaviors can discourage predators by:
- Illustrating superior escape abilities
56
Predation Risk Model
- assume the probability of death from the prospective of a prey item is based on
- > the rate of predator encounter
- > Probability of death per encounter with predator
- > Time spent vulnerable to encounters with a predator
- 3 lines of defense
1. Avoiding Encounters
- Don't encounter the predator at all
2. Avoiding Detection
- Detect the predator first to avoid the predator
3. Discouraging attacks
- Communicate to the predator that it is not worth the attack
4. Escaping attacks
- Once the predator decides to attack figure out a way to escape the predator
5. Avoiding Consumption
57
Optimal Foraging Methods
1. Prey Selection Model
2. Diet Selection Model
3. Patch Selection Model
4. Risk Sensitive Model
5. Predation-Foraging Trade-off
58
What do the Great tits Fast Birds vs Slow birds explain?
- Great tits differ in their exploratory behaviors.
- These differences are heritable.
- Slow females and fast males benefit in high food winters.
- Fast females and slow males benefit in low food winters.
- Pairs of opposites (fast-slow) have more offspring than like pairs (fast-fast or slow-slow)
- Habitat-specific and frequency dependent selection may both be important.
- The two sexes appear to be under different directional selection forces.
- >Thus, overall the effective type of selection is stabilizing to favor both phenotypes so one does not out compete the other
59
Optimal Diet Theorem
- A rate-maximizing forager will include less profitable prey items into their diet until the sum of rate of energy gain no longer increases from the addition of the next most profitable prey type.
60
Ecology of Communication: Channels
- Communication may be more or less effective depending on the limitations of the channel
- Multi-modal signals are those that employ multiple channels at the same time
1. Visual
2. Chemical
3. Auditory
4. Tactile
- Important signals often involve sequential assessments.
- These often utilize different channels of communication to increase effectiveness.
Ex: Elk use olfactory, auditory, visual and tactile channels
61
What are the potential constraints for the diet selection model?
1. If there is excessive handling time, or energy differences
2. If they have nutritional needs other than energy
3. If they need to balance the risk of predation
62
ESS solution for Hawk-Dove Model
- Can HAWK invade ALL DOVE population?
- > Yes it can
- Can DOVE invade ALL HAWK population?
- > Yes it can
- Therefore, neither ALL HAWK nor ALL DOVE is an ESS
- A mixture of HAWKS and DOVES might be evolutionary stable
- First solve the payoff matrix and then use the equations
- H = HvsH Payoff(h) +HxD Payoff (1-h)
- D = DvsH Payoff(h) + DvsD Payoff (1-h)
- > Set H = D and solve for h (the proportion of hawks)
- > Once you get the value for h plug it into the proportion of doves equation which is D = 1-h
- > convert these to percentages as well
63
Sensory Exploitation
- In the evolution of a signal, when a signaler is able to tap into a pre-existing sensitivity or bias in the perceptual system of the receiver, thereby gaining an advantage in transmitting a message to that receiver.
64
Evolution of Communication: Common Interests
- Sender and receiver have a common interest, such that there is no benefit to deceiving the receiver
- Mate recognition signals
-> most important signal
Ex: Why do ravens make loud calls at a carcass that attracts many other ravens to the kill?
- overwhelm the territorial pair hypothesis
-> call in a bunch of birds so that the territorial birds that carcass is available to everyone to defend it
65
Signal
- A unit of information transferred during communication that has come about by means of selection on both the sender and receiver.
66
Behavioral Syndrome
- a suite of correlated behaviors reflecting between individual consistency in behavior across multiple, such as two or more, situations
- A population or species can exhibit a behavioral syndrome
- Within the syndrome, individuals have a behavioral type
-> more aggressive versus less aggressive behavioral types
- individuals have behavioral types
-> bold, shy, passive, aggressive, active, inactive
- Populations have Behavioral Syndromes
-> individuals with fixed behavioral types
- Behavioral syndromes may even explain behaviors that appear to be maladaptive.
Ex: hyper-aggressive behavior in spiders is good for foraging and bad for mating!
67
Population Model Types
1. Evolutionary Stable Strategies (ESS)
2. Ideal Free Distribution
3. Ideal Despotic Distribution
4. Economic Defendability
68
Predation Risk Model: Avoiding Encounters
1. Reducing the alpha (probability prey avoids predator) or T (Time spent vulnerable to encounters with a predator) parameters
2. Change the Timing of Activity
- circadial patterns
- circatidal patterns
3. Change the Sheltering Behavior
- Crevices or burrows
- Commensal species
69
Dishonest Signals Mantis Shrimp example
- Mantis shrimp have claws that function like hammers or spear
- Fights are ritualized
- > They take turns hitting one another on their tail shield
- Usually fights are determined by claw displays
- Shrimp with the largest claws usually win by default
- Newly molted shrimp cannot strike but can still display
- > A few days before molting they attack neighbors more viscously pairing displays with strikes
- When the molt they continue to display often even though they cannot strike (deceptive signal)
- > This works for a day or two at the most until they harden up
- TAKEAWAY: Deceptive signals work only when they are rare and the majority of the time they are honest signals!
70
Give-Up Density
- Density of prey in a patch at the time of leaving as predicted by the marginal value theorem
71
Questions to ponder for the Hawk-Dove Model
- If you meet only once is it better to play hawk or dove?
- If you meet many times, is it better to play hawk or dove?
- > as the frequency of individuals in the population changes you are going to get different optimal strategies
72
How do ordinary behaviors become signals?
1. Intention Movements
2. Ambivalent Behavior
3. Protective responses
4. Autonomic responses
5. Displacement activities
6. Redirected attacks
73
Two Strategies in the Evolutionary Stable Strategy
1. Pure strategy
- each individual plays only one strategy all the time and does not change
2. Mixed strategy
- individuals may play different strategies at different times
74
Dishonest Signals: Why is deception rather rare in nature?
- All the observations of false signaling indicate that liars or deceptive callers are quickly identified in a population
- research show that individuals who give false alarm calls are no longer paid attention to after giving too many false alarms
- Deceptive signals work only when they are rare and the majority of the time they are honest signals!
75
Patch Selection Model
- general model used is the marginal value theorem
- Efficiency of energy gain in a patch is determined by how far the new patch is
- > make a decision based on how much resources you can use vs the time it takes to get to the next patch
- > if you have to take longer to get to the next patch you will stay longer and vice versa if the distance is shorter
- Give-up density (GUD) is the amount of food you leave behind in the patch compared to the maximum
- > When travel time between patches is short the give-up density (GUD) is larger and vice versa
- > However, this relationship did not change even when prey density in the patch changed
76
General Theory of Play: When may play be adaptive?
- Play may be adaptive if it
1. Trains specific motor or social skills that may be essential later in life
2. Aids in general cognitive development
3. Prepares animals to handle the physical and psychological challenges of unexpected events involving the loss of control
77
In an Evolutionary Arms Race what should prey do and what traits do they acquire?
- Avoid encounters
- Avoid detection
- Avoid capture
- Traits acquired:
1. Crypticity
2. Polymorphism
3. Spacing patterns
4. Mimicry
4. Evasive maneuvers
5. Defensive Weapons
6. Toxins
78
Channel of Communication: Tactile
1. Range = Short
2. Change = Fast
3. Obstacle = Poor
4. Locate = Easy
5. Cost = Variable
79
Hawk-Dove Model
- A game theory model of aggression with one strategy of escalation until it wins or is injured (Hawk) and another strategy of bluff escalation until it wins or it retreats (Dove).
- Hawk strategy
- > Always fight to injure and kill opponent
- Dove strategy
- > Always display but do not fight
- based on the pay offs for what strategy you play vs what your opponent plays
- John Maynard-Smith came up with this model
80
Ideal Despotic Distribution (IDD) Assumptions
1. Resources are distributed in patches
2. Competitors are unequal in their ability to exploit resources
3. Competitors may switch patches
4. Competitors have complete knowledge
5. Resource density remains constant
6. Intake rate increases with resource density and decreases with competitor density
81
Fox Farm Experiment; Hypothesis, Method, Results and Interpretation
- Selective breeding experiment that continues today
- Hypothesis
- > Selection for tameness could explain most traits shared by domesticate animals today
- Method
- > Selectively breed foxes according to how they react to humans
- Results
- > Tame foxes begin to show similar characteristics found in most domesticated animals, including dogs!
- Interpretation
- > Selection for tame personality is strongly correlated with changes in morphology and behaviors
- > Domestication syndrome
82
Bold-Shy Personality Axis
- Personality axis with a tendency to take risks, both familiar and unfamiliar, at one extreme and a reluctance to take risks, or engage in unfamiliar activities, at the other.
83
Ideal Free Distribution (IFD) Assumptions
1. Resources are distributed in patches
2. Competitors are equal in all respects
3. Competitors may switch patches at any time
4. Competitors have complete knowledge of how many resources and competitors are in each patch
5. Resource density remains constant
6. Intake rate increases with resource density and decreases with competitor density
84
Principle Component Analysis (PCA) Problems
- attempts to define the behaviors of an animal on a personality axis
- Problem with the PCA method is that there is always an axis regardless of how consistent the behaviors are.
- > Thus, an axis in one context cannot be compared to an axis in another context.
85
Dilution Effect
- Safety in numbers that comes from swamping the ability of local predators to consume prey.
86
Prey Selection Model
- Holling's Disc Equation
R = (Eg - Eh) / (Ts + Th)
-> Maximizes R = rate of energy intake based on aspects of how much energy you gain by eating one thing vs the cost it took to attain that food
-> Energy gained by consumption (Eg) vs energy lost to handling, or attaining that food (Eh)
-> Cost to eat that vs energy gained / time spent searching (Ts) + time spent handling (Th)
- Includes the rate of energy intake, energy gained by consumption, energy lost to handling, time spent searching and time spent handling
87
In the Patch Selection Model, how is the give-up density determined using the marginal value theorem?
- Give-up density (GUD) is the amount of food you leave behind in the patch compared to the maximum
- > When travel time between patches is short the give-up density (GUD) is larger and vice versa
- > However, this relationship did not change even when prey density in the patch changed
88
Proactive – Reactive Axis
- A personality axis with strong territoriality and aggression at one extreme and immobility and low aggression at the other
89
Time Minimizer
- An individual that maximizes the rate of energy gained per unit time by choosing prey (or patches) with the lowest time required (Ts + Th).
90
Categories of Communication: Non-Sexual Intraspecific
1. Specificity = Medium
2. Elements = Few
3. Deception = Medium
91
Habitat Selection Methods
1. Habitat Preferences
| 2. Ecological Traps
92
Context
- a functional behavioral category
| - > feeding, mating, anti-predator, parental care, contest or dispersal contexts.
93
In the Risk Sensitive Model, how do foragers respond differently to the risk of starvation vs. the risk of predation?
- starvation risk
- > behave differently by going to a high variable patch if starving and not the predicted method
- > starving are risk prone and satiated are risk averse
- Assumes that
1. Patches equal in mean rewards differ in their variance
2. A satiated forager should be risk-adverse and choose the less variable patch
3. A hungry forager should be risk-prone and choose the more variable patch
94
Assumptions of Patch Selection Model
1. Searching for patches and feeding within one are mutually exclusive
2. Encounters with patches are sequential and random
3. The gain function remains constant
4. Forager has complete information
- cant forage optionally unless they know these assumptions to make these decisions
95
In the diet selection model, what determines if a forager is a specialist or generalist?
- (E1h1 / E2) - h2 > 1 / lambda 1
- In nature being a generalist or specialist is set up by how many prey items you contact of your preferred type
-> only switch when a preferred prey item becomes rare
-> depends on the abundance of your preferred item
EX: Great Tit Experiment proved that it was the encounter rate of the most profitable pray, not the least profitable prey, that determined whether tits took the least profitable items
96
Evolutionary Trap
- in an environment that has been altered suddenly by human activities, an organism makes a maladaptive behavioral or life-history choice based on formerly reliable environmental cues, despite the availability of higher quality options
- You have an Original environment and response that has been naturally selected for many generations, but then you end up in a new environment where you respond to what you believe is the cue and it is not
- > This can also arise when the new environment happens to have a very similar cue to the original
- can either overestimate the quality of a bad habitat, or underestimate the quality of a good habitat
- If you have the right cue and the right quality, you have maximized your fitness
- > But you can perceive one environment to be really good and its not, then your fitness will go down
- > Underestimates of habitat quality may be just as bad
97
Communication
- The cooperative transfer of information from signaler to receiver.
98
Optimal Foraging Theory
- Evolutionary theories of behavior based on the assumption that the foraging behaviors of individuals are optimal by maximizing the rate of energy gained per unit time.
99
Ecology of Communication: Categories
- Categories describe the context of the information.
- The amount of information and the specificity of the signal increases with each category.
1. Sexual intraspecific
2. Non-sexual intraspecific
3. Interspecific
100
Diet Selection Model Factors When Deciding What to Consume
- prey encounter rate
- net energy gained from consuming they prey
- handling time of prey
- cost of search per unit time
Behavioral Ecology
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