SOCIAL BEHAVIOR

GROUP BEHAVIOR

SOCIAL BEHAVIORADVANCED BIOLOGYWINTER 2013

Free-Write(part 1)In your own honest opinion:

Do animals make decisions for the good of the group or for their own benefit?

Free-Write(part 2)In your own honest opinion:

Do humans make decisions for the good of the group or for their own benefit?

Social LifeWhy live in groups?

Social LifeWhy live in groups?

There are both benefits and costs. It all depends on the species if it is efficient to live in groups or not.

BENEFITSCOSTS (bad) vs. BENEFITS (good)COSTBENEFITPredator VigilanceCOSTS (bad) vs. BENEFITS (good)COSTBENEFITPredator VigilancePredator DetectionPredator VigilanceVigilance:

The action of keeping careful watch for possible danger or difficulties.Predator VigilanceIN SHORT:

Watching out for potential predators.

Predator VigilanceIN SHORT:

Watching out for potential predators.

The bigger the group, the more eyes there are to watch out for potential threats and the less time spent worrying about being eaten.Predator VigilanceExamples:

- Seals Lions.

Live in groups and look out for killer whales and other ocean predators.

What happens if you dont keep an eye out.COSTS (bad) vs. BENEFITS (good)COSTBENEFITPredator VigilancePredator DetectionPredator AvoidancePredator AvoidanceSafety in Numbers!Predator AvoidanceSafety in Numbers!

Two Forms:Dilution EffectGroup DefensePredator AvoidanceDILUTION EFFECT:

The probability of an attack on a single individual is less likely when there are a large number of animals in the group.What is the word dilution?16Dilution EffectExample: Flock of birds flying away from a predator.

Predator AvoidanceGroup Defense:

When the group of animals protect each other from predators through defensive strategies to try and get rid of predators.Group DefenseExample: Musk Ox defending their young.

COSTS (bad) vs. BENEFITS (good)COSTBENEFITPredator VigilancePredator DetectionPredator AvoidanceGroup ForagingGroup ForagingBy having more eyes, you are able to find resources more readily.

Also, if one individual is a skilled forager, it may lead others to food or may give others an opportunity to learn skills needed to forage.Group ForagingExamples:

Pack Hunters HyenasMay be easier to take down bigger prey with a group rather than by self.Group ForagingExamples:

Pack Hunters HyenasMay be easier to take down bigger prey with a group rather than by self.

Grazers Deer, Elk, etc.Some grazers may know better places to what to eat and young may learn.COSTSCOSTS (bad) vs. BENEFITS (good)COSTBENEFITPrey DisturbancePredator VigilancePredator DetectionPredator AvoidanceGroup ForagingPrey DisturbanceThe more individuals you have in the group, the more difficult it may be to get a meal.Prey DisturbanceThe more individuals you have in the group, the more difficult it may be to get a meal.

This could be due to:Prey DisturbanceThe more individuals you have in the group, the more difficult it may be to get a meal.

This could be due to:Scaring off the prey (prey has predator vigilance / detection).Prey DisturbanceThe more individuals you have in the group, the more difficult it may be to get a meal.

This could be due to:Scaring off the prey (prey has predator vigilance / detection). Depleting the resource.COSTS (bad) vs. BENEFITS (good)COSTBENEFITPrey DisturbancePredator VigilanceFood SharingPredator DetectionPredator AvoidanceGroup ForagingFood SharingMORE MOUTHS TO FEED!

Group DynamicsThe ways in which groups of animals interact.SOCIALBEHAVIORINDIVIDUALFITNESSGROUPFITNESSEGOISTICCOOPERATIVEALTRUISTICREVENGEFULGroup Dynamics4 Main Types of Social Behaviors:

1. EgoisticEgoismWhen an organism behaves in a way that only benefits itself. This may be at the expense of another organism.

EgoismWhen an organism behaves in a way that only benefits itself. This may be at the expense of another organism.

Increased fitness for the acting organism

EgoismWhen an organism behaves in a way that only benefits itself. This may be at the expense of another organism.

Increased fitness for the acting organismDecreased fitness for the receiver

Group Dynamics4 Main Types of Social Behaviors:

1. Egoistic2. CooperativeCooperationWhen an organism behaves in a way that benefits all individuals involved.

CooperationWhen an organism behaves in a way that benefits all individuals involved.

Increased fitness for the acting organism

CooperationWhen an organism behaves in a way that benefits all individuals involved.

Increased fitness for the acting organismIncreased fitness for the receiver

Group Dynamics4 Main Types of Social Behaviors:

1. Egoistic2. Cooperative3. AltruisticAltruismWhen an organism behaves in a way that does not benefit itself, but does benefit all other individuals.

AltruismWhen an organism behaves in a way that does not benefit itself, but does benefit all other individuals.

Decreased fitness for the acting organism

AltruismWhen an organism behaves in a way that does not benefit itself, but does benefit all other individuals.

Decreased fitness for the acting organismIncreased fitness for the receivers

Group Dynamics4 Main Types of Social Behaviors:

1. Egoistic2. Cooperative3. Altruistic4. RevengefulRevengefulWhen an organism behaves in a way that does not benefit itself, and does not benefit any other individuals of the group.

RevengefulWhen an organism behaves in a way that does not benefit itself, and does not benefit any other individuals of the group.

Decreased fitness for the acting organism

RevengefulWhen an organism behaves in a way that does not benefit itself, and does not benefit any other individuals of the group.

Decreased fitness for the acting organismDecreased fitness for the receivers

SOCIALBEHAVIORINDIVIDUALFITNESSGROUPFITNESSEGOISTICCOOPERATIVEALTRUISTICREVENGEFULSOCIALBEHAVIORINDIVIDUALFITNESSGROUPFITNESSEGOISTIC+COOPERATIVEALTRUISTICREVENGEFULSOCIALBEHAVIORINDIVIDUALFITNESSGROUPFITNESSEGOISTIC+-COOPERATIVEALTRUISTICREVENGEFULSOCIALBEHAVIORINDIVIDUALFITNESSGROUPFITNESSEGOISTIC+-COOPERATIVE+ALTRUISTICREVENGEFULSOCIALBEHAVIORINDIVIDUALFITNESSGROUPFITNESSEGOISTIC+-COOPERATIVE++ALTRUISTICREVENGEFULSOCIALBEHAVIORINDIVIDUALFITNESSGROUPFITNESSEGOISTIC+-COOPERATIVE++ALTRUISTIC-REVENGEFULSOCIALBEHAVIORINDIVIDUALFITNESSGROUPFITNESSEGOISTIC+-COOPERATIVE++ALTRUISTIC-+REVENGEFULSOCIALBEHAVIORINDIVIDUALFITNESSGROUPFITNESSEGOISTIC+-COOPERATIVE++ALTRUISTIC-+REVENGEFUL-SOCIALBEHAVIORINDIVIDUALFITNESSGROUPFITNESSEGOISTIC+-COOPERATIVE++ALTRUISTIC-+REVENGEFUL--EXIT SLIPPlease answer the following questions about class this week honestly:

1. What was the best part of this class?2. What was the worst part of this class?3. Suggestions for making the worst part better:------