Behavioural Ecology Flashcards
What is behavioural ecology?
Behavioural ecology is the study of how behaviour affects evolutionary fitness within an animals ecological context
Which of Tinbergen’s 4 ‘questions’/explanations does behavioural ecology fit into?
Adaptive value
Behavioural ecology does also focus on the other questions as well but to varying degrees dependent on the scientists research angle
Adaptive value is usually used to study behavioural ecology because behavioural ecology is often studied in terms of fitness costs and benefits of alternative behaviours
What 3 things does behavioural ecology usually relate to in terms of interactions between things?
Behavioural ecology usually relates to interactions between:
- animals within a population
- animals within an ecological community
- animal interactions with a habitat
How can behavioural differences between individuals lead to genetic differences?
The behavioural differences caused by their genetics can affect the chances of genes passing to the next generation
If the behaviour is more beneficial to the animal it will increase the chances of the genes being passed down the generations
What does behavioural ecology combine?
Ethology
Experimental psychology
What is ethology?
Ethology = the science of animal behaviour
What is experimental psychology?
Experimental psychology = the branch of psychology with the scientific investigation of the responses of individuals to stimuli in controlled situations
What models does experimental psychology use?
Experimental psychology can use either human models or non-human animal models
Behavioural ecology combines ethology and experimental psychology to do look at what 3 things?
1) Mathematical models are generated on an animals decision about:
- when to perform a behaviour
- how to perform a behaviour
2) Understanding how the animals perceptual abilities and motivational systems allow the behaviour to be performed appropriately and in the right context
- This would be looking at Tinbergen’s causal explanation as well as the adaptive value explanation
3) Within behavioural ecology ‘decisions’ don’t have to be conscious ones and can range from physiological to conscious behaviours
- An example of a physiological behaviour would be how many offspring an animal can have
What is an example of how closely linked animals are to the environment?
The decisions about eating:
- when to eat
- what to eat
- where to eat
How can the animals need to eat food that’s right for them be seen in their physiology?
An animals need to eat the correct food can be seen in differences in each animals digestive systems that are adapted to be able to extract nutrients from a particular type of food
What happens if the animals brain isn’t in tune with its digestive tract?
If the animals brain isn’t in tune with the digestive tract it could eat the wrong food which it can’t digest and may develop health issues
However, the animals perceptive systems and sensory perceptions are really tailored towards being attracted to areas and features that are likely to have the correct foods
Within behavioural ecology what kind of questions would you look at?
Do animals behave optimally?
Do they make the best available trade-offs between the costs and benefits of performing the behaviour?
What exactly are the costs and benefits that the animal can perceive?
What is one of the earliest and most famous models used in behavioural ecology?
1 of the earliest and most famous models used in behavioural ecology is the ideal free distribution model
What assumptions does the ideal free distribution model work on?
The ideal free model works on the assumption that when animals choose where to be they’ll assess how much resources are in 1 area and then go to the area with enough resources for them
What is the ideal free distribution model used for?
The ideal free distribution model is used to predict the number of animals in each area
The ideal free distribution model assumes that the number of individual animals in each of the various areas should be proportional to the amount of resources available in each area
This allows you to see how much of a resource an animal will have despite there being other animals using it as well
In the ideal free distribution model what are the areas known as?
Patches
Why is the ideal free distribution model called ideal?
It’s called ideal because it assumes that animals are aware of each patch’s quality, and that the animal sensibly chooses to forage in the highest quality/quantity patch
Why is the ideal free distribution model called free?
It’s free because it also assumes that animals are capable of moving unhindered from 1 patch to another
However, it may not work out that way due to other reasons
In real life ideal free distribution model predictions do come out roughly correct. However what 5 things can influence ideal free distribution models to make them wrong?
Any sort of imperfect knowledge Animal social dynamics Risk of predators at some patches Hassle of moving to another patch Illness or injury
What can we learn if an ideal free distribution model’s prediction fails?
When ideal free distribution models fail it can reveal things about the animals priorities and the constraints on them that cause them to not make the ideal/optimum choice
This means we can understand which factors effect animal decision making more clearly
What are optimality models and how do they work?
Mathematical optimality models are often used to predict what trade offs animals should make
Optimality models basically make predictions about how much behaviour an animal should do
You’d then study the animal to see if the behaviour matches the model and if it doesn’t match you’d then explore the reasons why
Name an optimality models for foraging
Optimality foraging theory models
What assumption do optimality foraging theory models work on?
Optimality foraging theory focuses on the assumption that animals should forage in such a way as to maximise the amount of energy gained
What is the optimality foraging theory models equation and what do the units mean?
E
H
E = the food determines the energy gained
H = handling time
The handling time describes the energy lost during:
- searching for the food
- obtaining the food
- digesting the food
What can optimality foraging theory models help explain?
Optimality foraging theory can help explain why animals eat some foods but not others
What are 2 disadvantages to optimality foraging theory?
Because it uses energy as a single currency for cost and benefits it doesn’t account for needs for other nutrients
Due to this optimality foraging theory models wouldn’t be able to explain why birds fly for miles to lock salt or minerals
Optimality foraging theory also can’t explain why animals often prefer difficult options for feeding
This can be seen with the phenomenon known as ‘contra-freeloading’
Give some examples of contra-freeloading
An example of contra-freeloading is seen in captive rats and some other animals
The captive rats will often prefer sunflower seeds with shells on rather than pre-shelled seeds
Puzzle feeders are commonly given to captive animals as environmental enrichment but animals will sometimes choose to get food from the puzzle feeders instead of freely available food
What is a possible reason for contra-freeloading?
A suggestion for contra-freeloading is that it could offer learning opportunities for the animals
What are the 3 components of optimality models and there meaning?
1) Currency
- This is what they’re measuring for to compare between each individual animal
2) Constraints
- This is what the model can’t account for in its predictions
3) Decision variable
- This is the number of alternative behaviours the animal can perform
Name 2 optimality models?
Ideal free distribution
Optimality foraging theory
What are the currencies of the 2 optimality models?
Ideal free distribution
Currency = amount of food an individual animal can eat
Optimality foraging theory
Currency = energy
What are the constraints of the 2 optimality models?
Ideal free distribution
Constraints = - imperfect knowledge
- cost of moving
- risk of predation
Optimality foraging theory
Constraints = - Handling time
- learning opportunities
- special nutritional needs
What are the decision variables of the 2 optimality models?
Ideal free distribution
Decision variable = move to a new patch or stay in current patch
Optimality foraging theory
Decision variable = eat food or not
What situations are animals usually altruistic in?
Usually animals are only altruistic to their relatives
What has recent research been looking at in terms of altruism?
Some research has also been geared towards whether or not reciprocal altruism can occur between non-relatives
What is reciprocal altruism?
Reciprocal altruism= I’ll help you if you help me
Does reciprocal altruism reduce fitness?
Reciprocal altruism reduces fitness in individuals only temporarily, until the generosity is repaid by the other individuals
How has cooperative behaviour such as reciprocal altruism been modelled?
Using game theory
Give an example of a game theory
Prisoners dilemma
What are the 4 situations that Trivers 1971 says that reciprocal altruism can occur?
1) The individuals must be able to recognise each other
2) The chance of meeting again must be high
3) They must remember how each other behaved last time
4) it helps if there’s a cost to behaving selfishly
In game theory what are the 2 options?
Cooperation
Defect
Explain the behavioural ecology tit-for-tat model
The tit-for-tat model is a development of cooperate/defect models, but the individual will repeat the ‘game’ over and over again
If each player starts by behaving altruistically and each player does whatever the other did last time the altruism can evolve
This can lead to altruism being the best strategy
However as soon as an individual behaves selfishly they enter a ‘death spiral’ and are soon out of the ‘game’
Modellers can also add different conditions into the model and see how it affects whether altruism is sustainable or not
Explain the behavioural ecology hawk-dove game?
The hawk-dove game is a ‘game’ that looks at whether animals should fight over resources (like a hawk) or just resolve disputes peacefully (like a dove)
Which behaviour is chosen depends on:
- the value of the resource
- the cost of fighting
In the hawk-dove game what is the value of a resource known as?
V
In the hawk-dove game what is the cost of fighting known as?
C
What are the 3 potential outcomes of the hawk-dove game?
1)
_V-C_ , _V-C_
2 2
Both players choose hawk leading to:
- each player has half a chance of injury
2)
V, O
When 1 player chooses hawk but the other chooses dove this leads to:
- the hawk player winning and getting all the resource
- no one is injured
3)
V , V
2 2
When both players choose dove this leads to:
- no one is injured
- they only get half the resource
- they only have half a chance to get the resource
In the hawk dove game what does the success of each strategy depend on?
Resource value
Cost of fighting
How likely each individual is to play hawk or dove
In what situations will each option in the hawk-dove game be better when the cost of fights is greater than the value of the resource?
When the cost of fights is greater than the value of the resource and the population has more individuals favouring dove approaches hawks will win because they get all the value and no cost
When the cost of fights is greater than the value of the resource and the population has more individuals favouring hawk approaches dove will win
The doves win because they won’t get the resource but they won’t get injured
Explain the evolutionary equilibrium between the 2 strategies in the hawk-dove game
The hawk-dove game can result in an evolutionary equilibrium between the 2 strategies
Which strategy is best depends on the aspects of each individual situation
At 1 time doves are better until there’s too many doves so hawks become better until there’s too many hawks then doves are better
These fluctuations continues forever
Where the equilibrium point of the fluctuations lies depends on the cost and Vue of each strategy in a given situation
Explain the evolutionary equilibrium between the 2 strategies in the hawk-dove game
The hawk-dove game can result in an evolutionary equilibrium between the 2 strategies
Which strategy is best depends on the aspects of each individual situation
At 1 time doves are better until there’s too many doves so hawks become better until there’s too many hawks then doves are better
These fluctuations continues forever
Where the equilibrium point of the fluctuations lies depends on the cost and Vue of each strategy in a given situation
Summarise behavioural ecology
Behavioural ecology is about how animals have to make trade offs between costs and benefits of doing each behaviour
Usually we find that animals behave near-optimally (on average) once we understand the true costs and benefits of the behaviour
Sometimes imperfect knowledge and other constraints can cause animals not to behave optimally
In any 1 observation luck can play a role
This is because risks and benefits are never certain they’re only based on probabilities
Summarise behavioural ecology
Behavioural ecology is about how animals have to make trade offs between costs and benefits of doing each behaviour
Usually we find that animals behave near-optimally (on average) once we understand the true costs and benefits of the behaviour
Sometimes imperfect knowledge and other constraints can cause animals not to behave optimally
In any 1 observation luck can play a role
This is because risks and benefits are never certain they’re only based on probabilities
