1. travismulthaupt.com Chapter 51 Behavioral Ecology

2. travismulthaupt.com Behavioral Ecology  The scientific observation of animal behavior, what controls it, how it develops, evolves, and contributes to the reproductive success of an organism.

3. travismulthaupt.com Behavioral Ecology  Understanding animal behavior is important to conserving endangered species and controlling the spread of infectious diseases.

4. travismulthaupt.com Animal Behavior  There are two main classes of questions that can be asked about animal behavior:  1. Those that focus on immediate stimulus and mechanism of behavior.  2. Those that explore how the behavior contributes to the survival and reproductive success.

5. travismulthaupt.com What Is Behavior?  It is a phenotype--a product of our genes.  Behavior is everything an animal does, and how it does it.  Behavior can also be learned.

6. travismulthaupt.com Proximate and Ultimate Questions  The observation of behavior involves proximate and ultimate questions.  Proximate questions focus on the stimulus and what triggers the behavior.  Ultimate questions address the evolutionary significance of a behavior.

7. travismulthaupt.com Proximate Questions  Again, these focus on the stimulus and what triggers it.  Additionally, it seeks the genetic, physiological, and anatomical mechanisms underlying the behavior.  Most importantly: these are mechanism and development questions.

8. travismulthaupt.com Ultimate Questions  Address evolutionary significance of behavior.  They are often questions that propose a hypothesis about an observed behavior.

9. travismulthaupt.com 4 Questions For Understanding Behavior  Proximate Questions (mechanism and development):  1. What is the mechanistic basis for behavior?  2. How does the development of the animal from the zygote to the mature individual influence behavior?

10. travismulthaupt.com 4 Questions For Understanding Behavior  Ultimate Questions (evolutionary):  3. What is the evolutionary history of the behavior?  4. How does the behavior contribute to the survival and reproductive fitness?

11. travismulthaupt.com Fixed Patterns and Imprinting  These are two behaviors frequently studied by ethologists.  Fixed Action Pattern (FAP) is a sequence of unlearned behaviors that are essentially unchangable.  Once initiated, they are carried to completion.  An FAP is triggered by an external sensory stimulus called a sign stimulus.

12. travismulthaupt.com Niko Tinbergen  A classic example of sign stimuli and FAP’s:  3-spined male stickleback fish.

13. travismulthaupt.com Niko Tinbergen  These fish attack other males invading their nesting area.  The stimulus comes from the red underside of the intruder.  The stickleback won’t attack any fish lacking a red-belly. Females don’t have red bellies.

14. travismulthaupt.com Niko Tinbergen  The male sticklebacks will attack fake models, unrealistic models, anything as long as some red is present.

15. travismulthaupt.com Imprinting  Imprinting is a type of behavior that involves both learning and innate components which are generally irreversible.

16. travismulthaupt.com Imprinting  The sensitive period of imprinting only lasts a limited time, and is the only time where certain behaviors can be learned.  During periods of bonding, young imprint on their parents and learn the basic behaviors of their species.  This is also the period of time where the parents learn the appearance of their offspring.

17. travismulthaupt.com Imprinting  If bonding doesn’t occur, death of the offspring usually results.  How and on whom do the young know to imprint?

18. travismulthaupt.com Imprinting  The tendency to respond is innate in the birds.  The outside world provides an imprinting stimulus, something to which the response will be directed.

19. travismulthaupt.com Konrad Lorenz  Lorenz experimented with geese.  Extensive research shows that behavioral traits are influenced by both genetic and environmental components. Just as much as are the anatomical and physiological traits.

20. travismulthaupt.com

22. Konrad Lorenz  In fact, Lorenz showed that geese (and other nidifugous birds) imprint on the first moving stimulus they see shortly after their birth. http://www.awakeningpotentials.com/images/imprinting2.jpg

23. travismulthaupt.com Nature Vs. Nurture  This is not a debate in biology. The question becomes: How do both the genes and the environment influence the development of phenotypes?  Behavior that is developmentally fixed is called innate behavior (nature).  Behavior that is a result of the environment is called learned behavior (nurture).

24. travismulthaupt.com Studying Nature Vs. Nurture-- Movements  Many movements are under genetic influence and are called “directed movements.”  Kinesis is a simple change in activity or turning rate in response to a stimulus.

25. travismulthaupt.com Kinesis Example:  Sow (pill) bugs survive best in moist environments.  They exhibit kinesis in response to variations in humidity.  They become more active only in dry areas.  They are less active in moist areas.

26. travismulthaupt.com Kinesis  The sow bugs don’t move toward or away from specific conditions.  Their increased movement in response to a dry condition increases the likelihood they will end up under a moist area.  When they reach a moist area, they slow down, and this increases the likelihood they will stay there.

27. travismulthaupt.com Taxis  Taxis is the movement toward or away from a stimulus.  Positive-toward.  Negative-away.

28. travismulthaupt.com Studying Nature Vs. Nurture-- Communication  Behavior can be controlled by signals and responses.  The transmission of, reception of, and response to signals constitute communication.

29. travismulthaupt.com The Types of Animal Signals  There are two main types:  1. Chemical signals  2. Auditory signals

30. travismulthaupt.com Chemical Signals  Chemical signals and pheromones are genetically controlled and elicit a behavior in other animals.

31. travismulthaupt.com Auditory Signals  Some animals such as birds and insects sing songs.  Others make noises with their body parts. These songs are related to courtship rituals and are under genetic control (nature), learned control (nurture), and/or both.

32. travismulthaupt.com Natural Selection  Natural selection favors behaviors that increase survival and reproductive success.  This can be observed in nature.

33. travismulthaupt.com Optimal Foraging  Optimal foraging behavior looks at the process of hunting for food as a compromise between the nutritional benefits of gathering food and the energy costs of obtaining food.

34. travismulthaupt.com Optimal Foraging  According to this theory, natural selection favors the individuals that utilize a foraging behavior that minimizes energy costs while maximizing energy output.

35. travismulthaupt.com Optimal Foraging  Example:  The energy cost-benefit of dropping molluscs on the coastal rocks by Northwestern crows.

36. travismulthaupt.com Sexual Selection  Recall that it is basically natural selection for mating success. Mates are chosen on the basis of their characteristics.

37. travismulthaupt.com Sexual Selection  Determining the basis of sexual selection in female zebra finches.  Females imprinted on their fathers, and this was demonstrated by experimenting with the young finches.

38. travismulthaupt.com Sexual Selection  Male zebra finches have a very ornate head compared to female finches.  On the heads of these birds were taped red feathers.  Different nests were examined.  Only males  Males and females  Just females

39. travismulthaupt.com Sexual Selection  These feathers were taped on before the eyes of the young were opened to determine which sex played a role in mate preference.  The results were compared to control groups of offspring whose parents had no headdresses.

40. travismulthaupt.com Sexual Selection  When the chicks matured, they were given a variety of mate choices.  Males had no preference at all toward ornamented or non-ornamented females.

41. travismulthaupt.com Sexual Selection  Females raised by non-adorned parents or females with a headdress, had no preference between ornamented or non-ornamented males.

42. travismulthaupt.com Sexual Selection  Females raised in families with the male having the red headdress preferred males with heads having headdresses suggesting females imprint on their fathers.

43. travismulthaupt.com Sexual Selection  These results also suggest that the mate choice selection by females plays a part in the evolution of ornamentation in male zebra finches.

44. travismulthaupt.com Sexual Selection  There are also forms of male competition for mates.  Male competition for mates is a source of intrasexual competition that can reduce variation. http://image16.webshots.com/16/1/42/94/183414294zHoflW_ph.jpg

45. travismulthaupt.com Agonistic Behavior  Agonistic behavior, for example, is a ritualistic type of competition that determines which competitors gain access to a resource such as food or mates.  The outcome can be determined by strength, size, or in the form of horns, teeth, etc.  They can be psychological in appearance.

46. travismulthaupt.com Preservation of Variation  Although the potential for reduced variation is there, there also exists a wide variety of individuals with a lot of behavioral and morphological adaptation.

47. travismulthaupt.com Preservation of Variation  Despite cases of reduced variation, there are many species that maintain variation.  Isopods that live within sponges are an example.

48. travismulthaupt.com , , and  Isopods  These genetically distinct males live within sponges.   -males defend sponges against other  - males.   -males mimic the female morphology and behavior. They get no response from  - males and have free access to the harem.   -males live within the harem.

49. travismulthaupt.com , , and  Isopods’ Mating Success  The mating success is dependent on the densities of males and female living within the sponges.  When one female lives in the sponge, the  - male fathers most of the offspring.  When there is more than one female, the  - male fathers 60% of the offspring.  As the harem size increases, the  -male’s reproductive rate increases.

50. travismulthaupt.com Conclusions  The information demonstrates that the reproductive success among the three different males is equal.  To explain the situation where natural selection fails to exclude any one variation (such as the one with the , , and  isopods), scientists use what is known as game theory.

51. travismulthaupt.com Game Theory  Game theory is used to explain the preservation of variation in the face of competition.  It evaluates the alternative strategies to a situation where the mating outcome depends on the strategies of all individuals involved in the process.

52. travismulthaupt.com Game Theory: An Example  The explanation of three different male phenotypes in populations of side blotched lizards in the inner coastal ranges of California.  There are 3 genetically controlled colors:  Orange throats  Blue throats  Yellow throats

53. travismulthaupt.com Game Theory  The frequencies of the individuals in the general population fluctuate between the 3 forms.  The relative mating success of these three morphs changes over time.  It’s similar to rock, scissors, paper.  Blue defeats yellow  Orange defeats blue  Yellow defeats orange

54. travismulthaupt.com Game Theory  Blue defeats yellow because they defend a smaller number of females in a smaller area.  They can’t defend against the aggressive orange.

55. travismulthaupt.com Game Theory  Orange moves in and defeats the less aggressive blue lizard and takes over a larger area with many females.  It now comes under attack from the sneaky yellow.

56. travismulthaupt.com Game Theory  Due to the large number of females in the orange lizard’s territory, he can’t defend against the sneaky yellow lizard who eventually takes over.  The cycle then repeats.

57. travismulthaupt.com Altruism  The selfless behavior of some animals that reduces their fitness, but increases the overall fitness of the population.  Example:  Belding’s ground squirrels give a high pitched warning signal but draw attention to themselves. http://www.sciencecases.org/kin_selection/squirrels.jpg

58. travismulthaupt.com Inclusive Fitness  Inclusive fitness helps to explain altruism. Giving off the warning signal helps to preserve the genes of the individual or of its close relatives.  Protecting offspring in the face of death helps to increase their genetic complement in the next generation.

59. travismulthaupt.com Reciprocal Altruism  This is a case where an animal will act altruistically toward another unrelated animal.  It is relatively rare, and is often observed in situations were the animals are likely to meet again where the favor can be returned.

60. travismulthaupt.com Reciprocal Altruism  It is a tit-for-tat strategy.  Cooperation is key.  U of M professors have studied it in animals.  Non-cooperative animals bring on retaliation until cooperation is reached.

61. travismulthaupt.com Social Learning  This is a way many animals learn through observation of others.  The transfer of information through social learning influences the behavior of others.

62. travismulthaupt.com Mate Choice Copying--A Form of Social Learning  Individuals in a population copy the mate choice of others.  A classic example of this involves guppies. http://www.aquariumschatzberger.com/images/lebendgebaerende/15392_guppy-maennchen-rote.JPG

63. travismulthaupt.com Mate Choice Copying--Social Learning  Female guppies in the wild prefer to mate with males showing a high percentage of orange coloration.  They also copy the mate choice of other females.  That is, they mate with males that have been successful at attracting other females.

64. travismulthaupt.com Mate Choice Copying--Social Learning  The experiment to demonstrate mate choice copying was as follows:  Female guppies were given the choice of mating with males of varying degrees of orange coloration.  Females were also given the choice between males with or without other females present.

65. travismulthaupt.com Mate Choice Copying--Social Learning  When the same degree of coloration in males was offered to females with another female present and engaging in a courtship ritual, the experimental females chose the males with little coloration.  They were copying the mate choice of the other females.  This demonstrated social learning.

66. travismulthaupt.com Mate Choice Copying--Social Learning  What this demonstrates:  Below a certain threshold of difference in male coloration, mate choice copying will mask the genetically controlled female preference for orange males.  A female that mates with males that are attractive to other females may increase the probability that her male offspring will also be attractive and have a high reproductive success.