L18 - Aggression and play

Question 1

Aggression vs predation?

Answer 1

Cannot confuse aggression with predation. Aggression is generally a defensive posture or attack either through threat or competition

Question 2

What are the reasons for aggression?

Answer 2

Defence (anti-predatory), courtship/reproduction and paternal care. Resource competition: inter-specific, intra-specific, territoriality, dominance

Question 3

What can be misleading in signaling aggression?

Answer 3

Reliance on body language

Question 4

Signalling aggression: Olfactory signals?

Answer 4

‘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.

Question 5

Signalling aggression: Auditory?

Answer 5

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

Question 6

What animals use several signals concomitantly?

Answer 6

Red deer in rutting use: visual - antlers/mane, auditory - roaring, olfactory - pre-orbital gland secretions.

Question 7

Defence - Anti-predations?

Answer 7

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.

Question 8

Reproduction?

Answer 8

Coercion of females to reproduce, clear advantages, often contested by the females. Male hamadryas baboons bully young females into staying within the harem.

Question 9

Parental care?

Answer 9

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

Question 10

Inter-specific competition?

Answer 10

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.

Question 11

Intra-specific competition?

Answer 11

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.

Question 12

Intra-specific competition: ritualised fighting?

Answer 12

Most fights are restrained or ritualised, avoid using most powerful weaponry. Often proceed through several stages, opposition may drop out at any time.

Question 13

Ritualised fighting: Red deer, Cervus elaphus?

Answer 13

Three main stages: start with roaring, then parallel walk, then lock horns. 25% of fights end in injury.

Question 14

Dominance hierarchies and social conflict?

Answer 14

Common but not universal in social organisations. Relationship between group members. Dominants have priority over subordinants. Concerns access to food, mates, resources.

Question 15

Selection dominance?

Answer 15

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.

Question 16

Dominance hierarchies in primates?

Answer 16

Many different social organisations in primates. Strikingly complex, form alliances between individuals. Status is determined in the short-term temporally by conspecifics.

Question 17

Dominance: Macaques?

Answer 17

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.

Question 18

Territoriality?

Answer 18

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.

Question 19

Territoriality: the owner wins?

Answer 19

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.

Question 20

Territoriality: A costly habit?

Answer 20

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

Question 21

Territoriality: A costly habit: Energetic defence ex?

Answer 21

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.

Question 22

Conflict between groups?

Answer 22

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.

Question 23

Defence?

Answer 23

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.

Question 24

Factors of aggression and dominance?

Answer 24

Territoriality, dominance, sexual, parental disciplinary, inter-specific comp, anti-predatory.

Question 25

Play?

Answer 25

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.

Question 26

How can play improve wellbeing?

Answer 26

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.

Question 27

What is play despite being a fun subject?

Answer 27

A contentious issue, most are stories from pet owners or anecdotes from zoo keepers, poorly studied, difficult to observe in a controlled environment.

Question 28

How can you define play?

Answer 28

Amorphous fuzzy behaviour, difficulty pinning down a meaning, always an ambiguous phrase used.

Question 29

What is the cost of play?

Answer 29

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.

Question 30

Types and functions: Object play?

Answer 30

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'.

Question 31

Types and functions: Locomotor play?

Answer 31

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.

Question 32

Types and functions: locomotion?

Answer 32

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.

Question 33

Types and functions: social play?

Answer 33

Playing with others. Three proposals: lead to forging long-lasting relationships, physical exercise, aid cognitive skills.

Question 34

Types and functions: social play and bighorn sheep?

Answer 34

Young males engage in more play fighting than females. Develops depending on how long the sheep have known each other. Differences in populations

Question 35

Types and functions: social play Squirrel monkeys?

Answer 35

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.

Question 36

General theory for the function of play?

Answer 36

Develop physical and psychological skills to handle unexpected events. Increase versatility of movements to recover from shock. Cope emotionally with unexpectedly stressful situations.

Question 37

Some correlations?

Answer 37

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.

Question 38

Summary?

Answer 38

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.