SOCIAL BEHAVIOR

1. SOCIAL BEHAVIOR ADVANCED BIOLOGY WINTER 2013

2. Free-Write(part 1) In your own honest opinion: Do animals make decisions for the good of the group or for their own benefit?

3. Free-Write(part 2) In your own honest opinion: Do humans make decisions for the good of the group or for their own benefit?

4. Social Life Why live in groups?

5. Social Life Why 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.

6. BENEFITS

7. COSTS (bad) vs. BENEFITS (good)

8. COSTS (bad) vs. BENEFITS (good)

9. Predator Vigilance Vigilance: The action of keeping careful watch for possible danger or difficulties.

10. Predator Vigilance IN SHORT: Watching out for potential predators.

11. Predator Vigilance IN 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.

12. Predator Vigilance Examples: - Seals Lions. Live in groups and look out for killer whales and other ocean predators. What happens if you don’t keep an eye out.

13. COSTS (bad) vs. BENEFITS (good)

14. Predator Avoidance Safety in Numbers!

15. Predator Avoidance Safety in Numbers! Two Forms: Dilution Effect Group Defense

16. Predator Avoidance DILUTION EFFECT: The probability of an attack on a single individual is less likely when there are a large number of animals in the group.

17. Dilution Effect Example: Flock of birds flying away from a predator.

18. Predator Avoidance Group Defense: When the group of animals protect each other from predators through defensive strategies to try and get rid of predators.

19. Group Defense Example: Musk Ox defending their young.

20. COSTS (bad) vs. BENEFITS (good)

21. Group Foraging By 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.

22. Group Foraging • Examples: • Pack Hunters – Hyenas • May be easier to take down bigger prey with a group rather than by self.

23. Group Foraging • Examples: • Pack Hunters – Hyenas • May 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.

24. COSTS

25. COSTS (bad) vs. BENEFITS (good)

26. Prey Disturbance The more individuals you have in the group, the more difficult it may be to get a meal.

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

28. Prey Disturbance • The 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).

29. Prey Disturbance • The 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.

30. COSTS (bad) vs. BENEFITS (good)

31. Food Sharing MORE MOUTHS TO FEED!

32. Group Dynamics The ways in which groups of animals interact.

34. Group Dynamics 4 Main Types of Social Behaviors: 1. Egoistic

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

36. Egoism When 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

37. Egoism When 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 Decreased fitness for the receiver

38. Group Dynamics 4 Main Types of Social Behaviors: 1. Egoistic 2. Cooperative

39. Cooperation When an organism behaves in a way that benefits all individuals involved.

40. Cooperation When an organism behaves in a way that benefits all individuals involved. Increased fitness for the acting organism

41. Cooperation When an organism behaves in a way that benefits all individuals involved. Increased fitness for the acting organism Increased fitness for the receiver

42. Group Dynamics 4 Main Types of Social Behaviors: 1. Egoistic 2. Cooperative 3. Altruistic

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

44. Altruism When an organism behaves in a way that does not benefit itself, but does benefit all other individuals. Decreased fitness for the acting organism

45. Altruism When an organism behaves in a way that does not benefit itself, but does benefit all other individuals. Decreased fitness for the acting organism Increased fitness for the receivers

46. Group Dynamics 4 Main Types of Social Behaviors: 1. Egoistic 2. Cooperative 3. Altruistic 4. Revengeful

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

48. Revengeful When 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

49. Revengeful When 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 Decreased fitness for the receivers