Lecture 12 Flashcards
Extensive vs intensive housing.
- extensive: closer to a natral setting such as free ranging animals
- intensive: way more animals, often a compromise of economics, management and welfare
Advantages and disadvantages of intensive groups.
Disadvantages:
* Eliminates choices
-no choice in habitat
-cannot choose to stay or leave
* No family structure
Advantages:
* Protected
* Food provided
* Health
* Generally lower fear levels
What is buller-steer syndrome?
A behavioural problem in groups of cattle that is recognized by the repeated mounting of one animal, the buller, by a group of animals, the riders
* Only happens in feedlots, does not happen in pastures becase of submissive behaviour, pheromones, warm weather, large group sizes and other stressful events (mixing, handling, temp, dust)
When will groups form?
not sure if this is split instead of form
- poor food availability
- breeding status
How are dominant-subordinate relationships are established?
- Tend to be the cornerstone of all relationships
- Creates rules by which other social relationship are controlled
What do hierarchies do for groups?
Hierarchy helps maintain order within the group
* it is specific to a particular group
Adding/removing animals disrupts order
Advantages/disadvantages for each rank
How does aggression differ between group sizes?
Important question
- small groups: **low **- linear hierarchy, not many to dominate - lowest aggression
- very large groups: hard to get hierarchy, medium aggression, don’t recognize each other, not as low as small groups so moderate
- Mid groups: highest aggression - hierarchy building all the time
What are the three hypothesis to determining dominance?
- Pairwise
* Strangers fight: rank order determined
* Might be over food sources, or mating
* Not a good indicator of hierarchies, might indicate aggressiveness levels - Continuous assessment
* Continuous fighting: rank order is fluid
* Occurs when groups are constantly changing
* generally only if memory and recognition do not occur - Suppression
* strangers fight: rank order determined
* dominants continue to attack/control subordinates to maintain status
Why is dominance maintained by subtle aggression and posturing?
Less energy and risk
Aggression vs dominance?
aggressivity = propensity to perform aggressive behaviour
dominance = rank within specific group, ability to control resources
* high aggression does not equal dominance
What is required with hierarchy development?
very improtant
Individual recognition
* How do animals know one-another
* Recognition tools differ by species (smell, sight, behaviour patterns)
-Different levels of complexity
- Recognition of all or only some group members
- Superficial or very detailed information on an individual
- At a complex level information about relationships
* Cognitive study in horses
- Recognition using visual, olfactory, and auditory cues
Memory of Past Encounters
* How long can they remember? (depends on species)
* ‘Social memory’ tested in horses and hens
- Familiar animals seperated & later reunited
- Horses - after 6 mos, returned to same rank with little interaction
- Hens - after few weeks, fought as much as unfamiliar birds to establish position
What are some examples of individual roles or strategies?
Bees:
* Queen - reproductive function
* Workers - different roles during different stages
* Drones - reproductive
Horses
* hierarchical rank of the foal is positively correlated to that of its mother
What are some individual roles or strategies?
Social status
* dominance rank
Role
* Groomer
* Leader
Strategies
* Producers and scroungers
Personality or temperament
What is a groomer?
- all dairy cows are groomed, but only 75% actually do the grooming
- grooming both cleans parasites and reduces tension
- absence of primary groomers reduces milk production
What is a leader?
- first to initiate grazing, travelling, or resting
- often older animal - ‘sociable’
- mid to high ranking, but not dominant
What are producers and scroungers?
Strategies in foraging
* Scrounger manages to exploit the work that the producer is doing
* Scroungers do best when outnumbered by producers
* ex. red deer: harem owner defends the group (producer), young males sneak matings (scroungers)
What are types of signals for group communication?
improtant
- Morphology, visual, chemical, sound
- Behavioural patterns, smells or structure used to affect behaviour of another
What are the factors that determine a signal will be received?
important
- Detectability (intensity, duration, occurence, repetition)
- Discriminability (distinguished the signal from other stimuli)
- Memorability (remember and associate the signal)
What is actor and reactor in group communication?
Cooperative signal and non-cooperative signal
Cooperative signal: the receiver benefits from detecting the signal (signals to a potential mate)
Non-coperative signal: the receiver does not benefit from detecting the signal (unintentionally attracting a predator)
Factors that can cause problems with signals?
- Interference
- Noise, visual interference
- visability or distance
- interests of sender & receiver
How can domestication change normal communication?
- Increased signalling: cats are good at talking to humans
- Group size: more noise, repetition and redundancy of the signal
- Barren environments: might be the only stimuli the animal can display, could lead to stereotypies
Can signals indicate internal states?
- age and species specific (distress calls in young animals, prey animals vocalize less)
- could be used to assess well-being
- dishonest calls: foraging birds and random calls (could lead to confusion)
What is crowding in intensive systems?
- groups of individuals whose movements are restricted by the physical presence of others
- higher likelyhood that animals come closer than their individual distance
- consequences can be aggression or avoidance behaviour
- some animals can be crowded without being overcrowded
- resouce availability and management are essential
intensive or extensive creates a difference in the types of groups especially…
- group size
- spacing
- sex distribution
what are the most important features of natural groups?
- group size
- offspring dispersal
- parent-offspring interations
how are groups maintained?
dominance hierarchy
What is the technical term for a housing system where we focus on a balance of welfare, management, and economics?
Intensive
What is the dominance rank?
represents an individuals relative position with respect to all other animals in the group.
Dominant - subdominant - subordinate
What is avoidance order?
- subordinate groups members avoid provoking those ranked above them
What are the most important factors to maintain a stable hierarchy?
Memory and recognition
What are the dominant roles?
- privilege including breeding status
- always at risk of loisng their status
- pairwise fights
-will depend on the likelyhood of injury - the higher the less likey they fight
What are alliances?
can affect hierarchies by destabilizing
X can defeat Y if Z helps
What is affiliative behaviour?
behaviours which promote and are important for group cohesion
