L18 - Aggression and play Flashcards
Aggression vs predation?
Cannot confuse aggression with predation. Aggression is generally a defensive posture or attack either through threat or competition
What are the reasons for aggression?
Defence (anti-predatory), courtship/reproduction and paternal care. Resource competition: inter-specific, intra-specific, territoriality, dominance
What can be misleading in signaling aggression?
Reliance on body language
Signalling aggression: Olfactory signals?
‘Stink fights’ in ring-tailed lemurs, the bigger, smellier group drives the other away using ‘chemical warfare’. Also includes musth secretions in ungulates and elephants.
Signalling aggression: Auditory?
E.g. songs of birds, call of crickets and frogs, howler monkey vocalisations, etc. The call may reflect the size and/or status of the caller
What animals use several signals concomitantly?
Red deer in rutting use: visual - antlers/mane, auditory - roaring, olfactory - pre-orbital gland secretions.
Defence - Anti-predations?
Vigorous defence to protect one-self or kins against predation, being eaten results in a fitness of 0. See significant behavioural and morphological adaptation to avoid this.
Reproduction?
Coercion of females to reproduce, clear advantages, often contested by the females. Male hamadryas baboons bully young females into staying within the harem.
Parental care?
Case of young taking advantage of parents, will continually beg until forced away. Commonly observed in adult moorhens can be aggressive to chicks. Reduce sibling rivalry and encourage independence
Inter-specific competition?
In nature resources are limited, niche overlap, lead to inter- and intra- specific competition. Can compete passively by taking all the resources needed, others fight for the rights. Kleptoparasitism, meaning parasitism by theft. Form of resource acquisition where one animal takes resources from another.
Intra-specific competition?
Natural selection would favour animals that compete successfully. Direct fighting is the most commonest form of competition. Yet in nature fights rarely cause injury. Animal avoid unrestrained battles. The greater the potential reward (e.g. the more mates), the greater the degree of tolerated potential damage.
Intra-specific competition: ritualised fighting?
Most fights are restrained or ritualised, avoid using most powerful weaponry. Often proceed through several stages, opposition may drop out at any time.
Ritualised fighting: Red deer, Cervus elaphus?
Three main stages: start with roaring, then parallel walk, then lock horns. 25% of fights end in injury.
Dominance hierarchies and social conflict?
Common but not universal in social organisations. Relationship between group members. Dominants have priority over subordinants. Concerns access to food, mates, resources.
Selection dominance?
Clearly advantageous to be dominant, natural selection must favour dominant individuals. But what decides dominance? Hen’s its larger size, also more testosterone, parasites affect dominance in mice, sex influences.
Dominance hierarchies in primates?
Many different social organisations in primates. Strikingly complex, form alliances between individuals. Status is determined in the short-term temporally by conspecifics.
Dominance: Macaques?
Organised in matrilines, females related by long-term bonds. Males are on the periphery. In conflict females are supported by female relatives. A social group may form a coalition of females, dominance is then dependent on the mothers status not by age.
Territoriality?
Three-spined sticklebacks (Garterosteus aculeatus), in spring males develop red bellies and become aggressive. Defend and exclusive area, if a male invades it is driven off, only attack trespassers.
Territoriality: the owner wins?
Owners are often stronger, territory owners have more to lose - worth more to the owner, prepared to fight harder, also have a more in-depth knowledge of the territory.
Territoriality: A costly habit?
Holding territories is widespread. Individuals without have lower fitness. Main reasons are for food or reproduction. Natural selection will favour territories when they are beneficial
Territoriality: A costly habit: Energetic defence ex?
Golden-winged sunbird, defends 1000-2000 flowers. Knowledge makes exploitation easier. The sunbird farms the nectar production. Restricts the size any territory holder can have. Costly to protect - larger the territory the larger the border to be guarded.
Conflict between groups?
Social groups can conflict over space or resources. Kidnapping ants - several species ‘raid’ opposing nests. Bring the offspring back to their nests. Use them as ‘slaves’ after emergence.
Defence?
Mobbing is a noisy, obvious form of behaviour that birds engage in to defend themselves or their offspring from predators. When a predator is discovered, the birds start to emit alarm calls and fly at the predator, diverting its attention and harassing it. Sometimes they make physical contact.
Factors of aggression and dominance?
Territoriality, dominance, sexual, parental disciplinary, inter-specific comp, anti-predatory.
Play?
Any pet owner will swear their animals play, can take many forms, many species participate (not universal). Young animals wrestle, chase, climb, jump, and chase prey that aren’t there. Commoner in larger brained vertebrates.
How can play improve wellbeing?
Pigface lived in a washington zoo, play with any object zoo keepers brought him, balls, pots, etc. Before this he would injure himself, self destructive behaviour stopped when toys were introduced.
What is play despite being a fun subject?
A contentious issue, most are stories from pet owners or anecdotes from zoo keepers, poorly studied, difficult to observe in a controlled environment.
How can you define play?
Amorphous fuzzy behaviour, difficulty pinning down a meaning, always an ambiguous phrase used.
What is the cost of play?
Play can incur a cost: energetic, danger from predators, injury. Cheetahs - Experiment measured the distance cubs run around and the distance from their mothers. Result showed: low cost activity, very rarely seriously injured, never under any serious threat from predation.
Types and functions: Object play?
Manipulation of inanimate objects. Well documented in a wide array of taxa of captive populations. Follows on from object ‘exploration’. Exploration appears to ask ‘what’ an object is. Play appears to ask ‘what can I do with it’.
Types and functions: Locomotor play?
Locomotor - rotational play: Leaps, hops, springs, bounces, etc. Provides exercise and training for specific motor skills needed later in life. Also provides a better understanding of the surrounding environment.
Types and functions: locomotion?
Beneficial functions: Increases creation of synapses in the cerebellum ‘cerebellum synaptogenesis. Plays a critical role in limb coordination, movement, posture, eye-limb coordination in mammals. More synapses develop earlier in ontogeny. May be due to experience.
Types and functions: social play?
Playing with others. Three proposals: lead to forging long-lasting relationships, physical exercise, aid cognitive skills.
Types and functions: social play and bighorn sheep?
Young males engage in more play fighting than females. Develops depending on how long the sheep have known each other. Differences in populations
Types and functions: social play Squirrel monkeys?
Play fighting and cognitive training, play fighting begins at 5 weeks old, generally only play with same sex partners. Dominance context, animals dominant outside of play will reverse roles to encourage play. Without role reversal subordinates would not play. Benefits of play then breakdown.
General theory for the function of play?
Develop physical and psychological skills to handle unexpected events. Increase versatility of movements to recover from shock. Cope emotionally with unexpectedly stressful situations.
Some correlations?
Amount of play will dictate how animals respond to stress in adulthood. Rats deprived of social play show neophobia. Rough-and-tumble human children become better problem-solvers.
Summary?
Difficult to define
object, locomotor and social play
object play is associate with proactive for later life
Locomotor provides exercise and trains specific motor skills
Social play: forms lasting bonds, sharpens skills and aids in the development of cognitive abilities.
Allows animals to develop the necessary responses to unexpected physical and psychological events later in life.
