5. Social Behaviour Flashcards
What are 4 advantages of group living?
- Animals in groups dilute their risk of predation
- reduced if larger groups are more likely to be detected
- risk dilution may be shared unequally among group members - Of value in defense of vulnerable young
- Help in detecting danger more reliably or quickly
- Group foraging leads to more efficient food detection
- but must share food resources
What 3 broad categories can social behaviour be divided into?
- Mutualistic behaviour (+/+)
- where both the ‘actor’ and the ‘recipients’ of the behaviour benefit
- would expect natural selection to favour (bc it’s a win-win) - Selfish behaviour (+/-)
- where the actor benefits but recipients experience a cost
- bc natural selection operates powerfully at the level of the individual, can be explained if behaviour traits increase the reproductive success of the individuals possessing them, even if they hurt others - Altruistic behaviour (-/+)
- where the actor experiences a cost while recipients benefit
What is an altruistic act?
An altruistic act by an individual is one which involves some cost to that individual in terms of reduced fitness but increases the fitness of one or more other individuals
When does reciprocal altruism occur?
Reciprocal altruism occurs when an altruistic act by A directed towards B is followed by some equivalent act by B directed towards A, or by an act directed towards A whose occurrence is made more likely by the presence or behaviour of B
- ex. allogrooming in cattle
What are 2 common ways in which altruism can be selected for?
- Kin selection
- heritable altruistic behaviours persist when they benefit the individual’s relatives - Reciprocation
- altruism btw non-relatives under conditions that allow for reciprocation
- cheaters can easily exploit, so only expect to see where social networks are STABLE enough for individuals to encounter one another frequently, individuals are IDENTIFIABLE, and cheaters can be ‘PUNISHED’
What are 2 basic types of defense mechanisms?
- Primary defense mechanisms
- operate regardless of whether or not there is a predator in the vicinity - Secondary defense mechanisms
- used when a predator is detected, is predicted, or “occurs”
What are 5 examples of primary defense mechanisms?
- Hiding in holes
- Exhibition of a warning of danger to predators
- Timing of activities to minimize the chance of detection by a predator
- Remaining in a situation where any predator attack is likely to be unsuccessful
- Maintaining vigilance to maximize the chance of detecting the advent of a predator
What are 6 examples of secondary defense mechanisms?
- Withdrawal to a safe retreat
- Flight and evasion
- most obvious avoidance tactic - Use of a display that deters attack
- Feigning death
- Behaviour that deflects attack
- Retaliation
- biting, fighting, butting, etc.
What happens to the anti-predator response in relation to a more dangerous stimulus?
The anti-predator response will be stronger to a more dangerous stimulus
- different from sensitization; this can be the first exposure and if the risk is perceived as more dangerous, the response will be stronger (not about repetition)
- this is an anti-predator strategies
As an anti-predator strategy, flight may be…
Socially controlled or uncontrolled
- when herd flight is controlled, animals will follow in their normal “travelling” order in which a high ranking female is often the leader
- when there is panic, flight is uncontrolled without commitment to any order
Defense reactions to man by farm animals
Man was a predator to the ancestors of our farm animals
- Still treated as a source of danger. Handlers learn to recognize stress responses in farm animals and minimize their occurrence
- If entering is preceded by a knock and the avoidance of unexpected movements and noises, such problems can be minimized
Competition
The situation where individuals seek to obtain the same resource
- need not be a physical confrontation; may be the fastest, cleverest or strongest that wins a competition
When is aggression mostly seen?
Mostly seen when groups of animals are first formed (eg when dominance hierarchy is being formed)
Agnostic behaviour
Includes all forms of behaviour by an animal associated with conflict with another animal
- embodies many of the behavioural activities of fight-or-flight and those of aggressive and passive behaviour
- form of fighting varies from species to species
- mock fighting is a variation of play behaviour (and is somewhat ritualized, as it has “rules”)
What are the fighting ABC’s?
- Subtle cues are given first to ward off an attack
- try to look BIG
- similar size animals fight more - Active fighting
- bites often made to the head or neck area
- biting, kicking, rearing, etc.
- vocalizations - Losing the fight
- losing animal will put distance btw itself and the other individual
- outside a “critical distance” an animal is less likely to attack
- distances vary depending on temperament, experience, comp for resources
*when dominance is established the encounter ends
Avoidance reactions can be what?
Passive = makes itself look small
Active = runs away
Social submission
- may vary from slight head depression with movement away from the stimulus, to assuming recumbency and refusing to rise
- similar to the behaviour of a sick animal
Flight distance
The radius of space within which the animal will not voluntarily permit the intrusion of man or other animals that might be dangerous without escaping
- in domesticated animals, the flight distance to man shrinks with appropriate husbandry and human socialization
- rxns to intrusions include startle, alarm, fight-or-flight display and vocalization
Home range
The area that the animal learns thoroughly and that it habitually uses
- Can contain a “core” area within it
Territory
An area that is defended by fighting or by demarcation, which other individuals detect so that the mark or other signal is a deterrent to entry
- may not be permanent
- smaller than the home range and not static
Individual Space (aka social space)
- The minimum distance within which approach elicits attack or avoidance (will vary by activity)
- Most animals actively preserve a minimum distance from themselves and attempt to prevent others from entering this space
What may spatial features be defined by?
Local geography
Association
In addition to maintaining individual space and defending territories, animals may also choose to remain close to certain other individuals
- eg. mother and offspring, animals reared together, mating pairs, etc
What 2 general categories does spacing behaviour fall into?
- Individual space that is defined in terms of the individual and hence moves with it
- Home range and territory, which refers to a static area used by the animal
What does spacing of the members of a social group at any moment depend upon?
The activities of the group members
Spatial needs in animals are both quantitative and qualitative. Explain.
Quantitative needs relate to space occupation, social distance, flight distance and actual territory
Qualitative needs relate to space-dependent activities such as eating, body care, exploration, kinetics, and social behaviour
What is ‘minimum spatial need’?
It’s for that amount of room that physical size and basic movements require
- length, breadth and height
Why is space needed for social reasons?
- Used to keep some separation btw itself and its conspecifics and to carry out avoidance behaviour (preserved by gestures of threat or intention)
- May be surrendered briefly without aggression in a variety of circumstances such as short-term crowding and resting
What is area of space occupied a function of?
Area of space occupied is a function of its wt (overall size, think volume, 3D) and of its need to perform various activities
- too often, “space allowance” is used incorrectly, it isn’t 2D but 3D
More accurately, what is space allowance?
- floor area = m^2
- doesn’t accommodate for vertical space
- used in laying hens - stocking density = m^3
- includes a vertical space allowance
- important bc when an animal grows (think of a pig) they grow in 3d (allometric growth)
- we use this all the time but never really state it in m^3 - floor pressure = kg/m^2
- wt per unit of area
- broilers
- broiler meat is on the quota system, based off of kg of chicken, so their space allowance is floor pressure (kg of chicken meat per floor area)
- tied to a supply managed system associated with a quota
*different units and these are associated with different livestock species
Crowding
Groups of individuals whose movements are restricted by the physical presence of others are said to be CROWDED
- high density of animals
- bc it intrudes on individual space, it CAN lead to aggression and fighting or even avoidance behaviour
Overcrowding
If a high social density causes adverse effects on the fitness of individuals then the term overcrowding is used
What are the 3 types of social organization?
- Physical structure:
- The size of the group and its physical composition in respect of age, sex and degrees of relatedness of group members - Social structure:
- All the relationships among individuals in the group and their consequences for spatial distribution and behavioural interactions - Group cohesion
- The DURATION of association of the members of the group and the frequency of fission in which one or more members leave the group
Hierarchy
An order of individuals or groups of individuals in a social group, based upon some ability or characteristic
- most frequently used where the ability assessed is that of winning fights or displacing other individuals
- can involve just two levels (despot) or a series of levels (linear)
What 4 things does stability of social relationships require?
- Recognition between individual animals
- Established social positions
- ‘Memory’ of social encounters that establish social status
- ‘Memory’ of observations of the behaviour of social group members
When does a stable social hierarchy form? What is more important than aggressive behaviour?
A stable social hierarchy forms when a group has been together for some time
- results in maximum bonding and minimal aggression
- the state of settled-out relationships btw individuals
- affiliative behaviour is more important than aggressive behaviour
What is social dominance usually exerted over?
Access to resources
- ex. feed, mates
What are 3 roles of individuals in a group?
- Leader
- the individual that is in front during an orderly group progression - Initiator
- the individual that is the first to react in a way which elicits a new group activity - Controller
- the individual that determines whether or not a new group activity occurs, when it happens, and which activity it is
How do animals often respond to the initiative of a lead animal?
By following!
- All herding and flocking animals show “follow reactions” in various social circumstances
What is the difference between social facilitation and allelomimetic behaviour?
Social facilitation: one animal does something and all the others then mimic it
Allelomimetic behaviour: all the animals doing the same thing at the SAME TIME
Social facilitation is more likely where there is what 5 factors?
- adequate association
- ability to communicate and react
- a potential for mimicking activities
- similarity of motivational state
- suppression of intra-species aggression
