Final Exam Flashcards
What is the landscape of fear?
predation is not a constant and varies depending on temporal and spatial scales. How prey precieve predation risks
What are some examples of animals in landscape of fear?
- birds in high predation make less or no children while in low predation there is more children
- When a sound of an apex predator plays, its first prey will decrease, increasing the secondary prey and decreasing the primary prey
What are indirect and direct cues?
indirect cues: carcasse (know theres a predator don’t know where though)
direct cues: see predator right away
What are non-consumption effects?
They sum up all the trade-offs.
In landscape of fear; it’s like fear effects, where the eating will be reduced, there will be a change in diet, increase stress
How do animals reduce incertainty?
By information
Social info: watch someone else (less reliable, less costly)
Personal info: see it yourself (more reliable, more costly)
What is the difference between adaptation and acclimatization?
Adaptation: genetics and evolution
Acclimatization: heretibility, “im hot im removing my coat”
What is the landscape of fear loop?
In a spatially and temporally variable predation risk place, there are natural limiting factors, which cause ecological uncertainty, which can be reduced by social and personal information, which causes natural limiting factors.
What drives uncertainty?
variation
What is the equation of probability of death?
Death = 1 - (adT)
a: rate of encounter of predators (how often over life an individual runs into predator)
d: probability of death given an encounter
T: time spent vulnerable to encounter (predator community)
What is the probablisitic approach of equation of death?
there are three probabilities for first encounter.
1. no encounter occurs (1-p-q)
2. prey detects predator first (p)
3. predator detects prey first (q)
The two ways it can end, is either the prey goes away or it dies
What factors affect the probablity of encounter? (a in the equation?)
- local densities of predators
- speed of movement through habitat (energy costly but decrease of encounter rate)
- habitat type
We assume that prey can assess probability of detection as they can modify behaviour depending on risk
What is the equation for probability of death (d)
D = probability of escaping if prey detects first + probability of escaping if predator detects first x probability of escaping following capture
What are the components of time spent at risk of predation? (T in the equation)
- Most flexible componen of anti-predatior strategy
- compromised of current and future predation threats (current = trade-offs, future = threat sensitive trade-offs)
What are the 4 predator avoidance strategies?
- habitat selection as predator avoidance
- crypsis
- behavioural predator avoidance
- predator recognition
What are examples of habitat selection as predator avoidance?
- habitat exclusion: live where depending on where your predators live
- selection for mating sites: salmon lay eggs where they arent expected too so predators dont eat
- territoriality as predator avoidance
active defense of territory can reduce time spent vulnerable to predation, familiarity of patch, defending for predator avoidance
What examples of crypsis?
- eucrypsis: looking like background
- mimicry: resembling something dangerous or indedible
- mullerian mimicry: all members of population look alike (aposomatic colouration)
- bastesian mimicry: look like something dangerous
What are examples of behavioural predator avoidance?
they can modify behaviour depending on predation risk
- bass alter repsonse to chemical cues depending upon microhabitat dont localise feces cause they arent ambush predator
What are examples of predator recognition?
- minnows avoid feces of pike that ate minnows.
- huge foraging costs for pike so with coevolution pike shit away
How to reduce attack probability?
Morphological mechanisms
- predator deterrents: spines on sticklebacks, scale plates on amphibians
- predator induced deterrents: induced morphological changes
Why dont all show similar anti-predator adaptation?
- increased costs associated with trait
How to reduce attack success?
Morphological defences which increase probability of survival after attack
- tissue regeneration
blue tail skink regenerate tail, black tail skink cant, so they stay hidden.
What are behavioural avoidance mechanisms?
Flee or freeze
- dependent on social grouping and economic decisions
What is the many eyes hypothesis? What are the costs?
As group size increases, time spent watching for predator decreases
Cost: as group size increases, consumption decreases, competition increases
Trade-Off: As group increases, less vigilance, more foraging
What is the oddity effect?
Odd morph is more vulnerable to predators
- if 90% sticklebacks and 10% minnows, minnows get eaten
- of 105 sticklebacks and 90% minnows, stickleback join shoals of minnows smaller than them
What is social order?
dominant status may afford anti-predator benefits.
ex: when salmon eat, they are drift eaters, when dominant fish seek shelter, little fish goes forage since no competition.
Is social order behaviour driven by dominance or past experience?
social context is shaping the behaviour
How does behaviour change when shoaling with familiar vs unfamiliar conspecifics
familar: allows for the shoaling of anti-predators, more salience, you know how they are going to respond, allowing for social learning
What does advertissing to the predator mean?
signals that the prey found the predator before the predator found the prey
What are two types of way to scare others in a shoal to increase survival?
- conspicuous display: dashing of minnows
- social warning signal: deer showing white patch on the inside of their tail
What predicts individuals will make context dependent behavioural decisions maximizing threat sensitive trade-offs?
selection should favour individuals that can reliably assess local predation risk and adjust response intenstity accordingly.
What are examples of maximizing threat sensitive trade-offs?
large or small trumpet fish shown horizontally or diagonally predator posture, and will give them different risks
What is Helfman prediction to pure-threat-sensitivity?
percieved predation risk should have proportional response intensity. The higher the risk the higher the intensity
What is the phenomen of high level of intensity no matter the perceived predation risk?
hypersensitivity
What is the phenomen of low level of instensity no matter the percieved predation risk?
nonchalance
How to get continuous variables and not categorical variables?
Get rid of visual cues, as you increase the concentration of these cues, you get an increase in response
What is the dynamic threat-sensitivity model?
predicts: social context shapes how an individual responds to threat
When Bantipredator is equal to Bforgaing, the relationship between predation risk and intensity will be linear, if Bap > Bfor, it will shift to hypersensitivty, if Bfor > B ap, it will shift towards nonchalance
What are the immediate benefits of group size and threat-senstive responses?
The smaller the group, the more hypersensitive the response. The larger it gets, the less hypersensitive they get
What is the predation risk allocation hypothesis?
prediction 1: as frequency of risk increases effort of respose allocated to each predation event should decrease
prediction 2: as frequency of risk increases, rate of foraging during “safe” periods should increase
Risk allocations vs habitation
risk allocation: an individual will reduce anti-predator responses during periods of high frequency risks
Habitation: high frequency risks all the time that causes the individual to ignore the risks and show no anti-predator response
What is the prediction of risk taking and fitness?
people with higher fitness will be more risk aversive while people with lower fitness will be more risk prone
What are the costs of sexual reproduction?
- meiosis (energy)
- genotype - measureable fitness cost
- over production of males
What are benefits of sexual reproduction?
- increase heterogeneity - sexual recombination
- resistance to mutations: mutations arent passed down
- reinforcement of pair bond
Sexual selection: Isogamous
- equal energetic investements of females and males, both gametes are of similar size
Sexual selection: Anisogamous
males and females produce unequal sized gametes
different strategies for either sex
What is Trivers take on sexual selection and parental investement?
if one sex invests more energy into reproduction, the lower investing sex should compete for access to higher investing sex.
what is sexual conflict?
Different optima point between the most vs the less investement sex
How does sexual conflict drive sexual selection?
the greater the distance between M and L (opitma points of the two sexs) the greater the secual conflict. The greater the sexual conflict the more pressure for sexual selection
What are the two types of sexual selection?
- intrasexual: competition amongst members of one sex (typically males)
- intersexual: choice of mates by the other sex (females)
What are examples of sexual selection?
- elaborate colouration: guppies (predation is a post-natal cost)
- sexual ornaments: beetles
- mating calls: crickets
- displays (male gather and the women choose)
What are the two models where the female benefits?
- direct benefit (good genes)
- indirect benefit (sexy sons)
What is the Good genes model?
males are chosen based on ability to provide resources, males benefit by defending a territory
What is the sexy sons model?
males chosen based on phenotype correlated with “high quality” genotype
What is runaway selection?
certain traits evolve very quickly
What are handicaps?
costly traits or behaviour to individual but shows to the mate they have good genetics.
Why are ornament displays honest?
because they are correlated to the quality of the individual. If high quality, high display
What is the distracted male hypothesis?
trade off predation response for reproductive activites
What is the hamilton and zuk: proximate mechanisms and handicap model?
argued increased energy demands of male displays increase pathogen/parasite infection
(more energy you spend on displays the less energy you have to fight off parasite)
What does MHC and mating prederence do?
MHC can be detected through fauna and hence urine cues, and so males with poor (parasite susceptible) MHC recieve fewer matings
What is the mate choice copying?
females will choose male phenotype that others have mated with to reduce time looking for mates
If females exhibit mate choice copying to reduce costs, then it is predicted that….
younger females, food depreived females, parasitized females show more copying
how do groups and size change depending on male absent or presetn?
girls will stay in smaller groups when no man is present to reduce competition, but larger when male is there for more info. When no male they dont care for the size of females they hang out with, but when male is present they hang out with larger females since they have more experience
What are the different mating systems?
monogamy: biparental care, one mate
polygyny: one male, multiple females (better for males)
polyandry: one female, multiple males (better for females)
promiscuity: multiple males, multiple females
