Groups
What is hamiltons rule and equation
He took the degree of relatedness into account when addressing altruistic social encounters
b > c/r
b = benefit (recipient)
C = cost (actor)
r = degree of related ness
What are the three hypotheses to determining dominance
Pairwise
Continuous assessment
suppression
What 3 factors determine if signals are received
Detectability
Discriminability
memorability
What are the benefits of groups
Foraging - detecting food, acquiring food, defending food
Predation - detecting, dilution, defense
Thermal
What is stocking density
Animals / unit area
Why would non relatives cooperate
Assume that cooperation results in a cost to actor with no payoff
Reciprocal altruism - alternating benefits = long term relationship
Multi level selection - groups that cooperate outcompete those that dont
What is the pairwise hypothesis to determining dominance
Strangers fight - to determine order
Might be over food sources
This is not a good indicator of hierarchies, but might indicate aggressiveness level
Interference
noise, visual interference
visibility or distance
interests of sender or receiver
What are the costs of groups
Groups are more easily detected, predators can be attracted by communication
Competition - competition and prioritized access to food, acute stress when forming a group, chronic stress from subordination
Contamination - increased parasite and disease transmission
Whats the difference between usable space and total space
Total - everything inside the boundary line
usable - area animals can actually occupy comfortably
Design can make space unusable
What are the advantages and disadvantages of intensive operations
Dis - eliminates choice = no choice for habitat, cannot choose to stay or leave, no family structure
Ad - protected, food provided, health, generally lower fear levels
What is the Continuous assessment hypothesis to determining dominance
Continuous fighting - rank order is fluid = occurs when groups are constantly changing
Generally only if memory and recognition do not occur
How can domestication change normal communication
Lead to increased signaling
Group size - bigger means more noise
Barren environments
How do you minimize costs in a group
Limit group size
Social hierarchy
Social rules to reduce competition
whats the functions of space
Space is required because animals have goals - rest, move, avoid, explore, socialize and access resources
Posture changes
locomotion
thermoregulation and microclimate choice
social spacing = avoidance and affiliation
What do the most welfare friendly systems incorporate
Important features of natural groups - like group size, offspring dispersal, parent-offspring interactions
What is the suppression hypothesis to determining dominance
strangers fight
Dominants continue to attack/control subordinates to maintain status
What are the different strategies individuals use
Dominants - pairwise fights
Alliances
What is space allowance
What is provided to each animal
usually expressed as m2./ animal
Easy to regulate and audit
Can be misleading if usable space is smaller than paper space
What are resources in a pen
Lying space
feeder space
drinker
bedding, rooting materials, enrichment
What is the most aggressive group size to the least aggresive
Most = mid groups
middle = very large groups
Least = small groups
What is the difference between aggression and dominance
Ag - propensity to perform aggressive behaviour
Dom - Rank within specific group, ability to control resources
What are different roles individuals play in a group
Groomer - affiliative behaviours promote group cohesion, all cows are groomed but only 75% do the grooming
Leader - often older animals, initiate travelling resting or grazing, not dominant
What is space requirement
What an animal needs to perform key behaviours and maintain health
Depends on body size, shape, behavioural repertoire, social context, and environment
Often differs by function
can change over time
What does size of a territory depend on
Species
gender of the animal
Food availability
Predators