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
