Chapter 51: Animal Behavior

1. Chapter 51: Animal Behavior

2. Humans have probably studied animal behavior for as long as we have lived on Earth • As hunters knowledge of animal behavior was essential to human survival

3. Figure 51.1 • Cranes are birds that have captivated people’s interest • Possibly because they are large and their behavior is easily observed

4. Dorsal fin Anal fin Figure 51.2 What Is Behavior? • What an animal does and how it does it • Includes muscular and nonmuscular activity

5. Learning • considered a behavioral process

6. Proximate, or “how,” questions • Focus on the environmental stimuli that trigger a behavior • Focus on the genetic, physiological, and anatomical mechanisms underlying behavior

7. Ultimate, or “why,” questions about behavior • Address the evolutionary significance of a behavior

8. Ethology: Scientific study of animal behavior

9. Fixed Action Patterns (FAP) • Sequence of unlearned, innate behaviors that is unchangeable • Once initiated, is usually carried to completion • Triggered by an external sensory stimulus • (sign stimulus)

10. (a) A male three-spined stickleback fish shows its red underside. Figure 51.3a • In male stickleback fish, the stimulus for attack behavior • Is the red underside of an intruder

11. (b) The realistic model at the top, without a red underside, produces no aggressive response in a male three-spined stickleback fish. Theother models, with red undersides, produce strong responses. Figure 51.3b • As long as some red is present in a model, the attack behavior occurs

12. BEHAVIOR: A male stickleback fish attacks other male sticklebacks that invade its nesting territory. PROXIMATE CAUSE: The red belly of the intruding male acts as a sign stimulus that releases aggression in a male stickleback. ULTIMATE CAUSE: By chasing away other male sticklebacks, a male decreasesthe chance that eggs laid in his nesting territory will be fertilized by another male. Figure 51.4 • Proximate and ultimate causes for the FAP attack behavior in male stickleback fish

13. Imprinting • Behavior with both learning and innate components and is generally irreversible • Sensitive period • limited phase that is only time when certain behaviors can be learned

14. Konrad Lorenz showed that • When baby geese spent the first few hours of their life with him, they imprinted on him as their parent

15. BEHAVIOR: Young geese follow and imprint on their mother. PROXIMATE CAUSE: During an early, critical developmental stage, the young geese observe their mother moving away from them and calling. ULTIMATE CAUSE: On average, geese that follow and imprint on their mother receive more care and learn necessary skills, and thus have a greater chance of surviving than those that do not follow their mother. Figure 51.5 • There are proximate and ultimate causes for this type of behavior

16. Figure 51.6 • Program to save the whooping crane from extinction

17. Biologists study the ways both genes and the environment • Both influence the development • Behavior that is developmentally fixed is called innate behavior, under strong genetic influence

18. Kinesis • Simple change in activity or turning rate in response to a stimulus

19. Moist site under leaf Dry open area (a) Kinesis increases the chance that a sow bug will encounter and stay in a moist environment. Figure 51.7a • Sow bugs • Become more active in dry areas and less active in humid areas

20. Taxis • Automatic, oriented movement toward or away from a stimulus

21. Direction of river current (b) Positive rheotaxis keeps trout facing into the current, the direction from which most food comes. • Fish exhibit positive rheotaxis • automatically swim in an upstream direction Figure 51.7b

22. Figure 51.8 Migration • Genetically programmed

23. Animal Signals and Communication • Signal behavior that causes a change in another animal’s behavior • Communication reception of and response to signals

24. Animals communicate using • Visual, auditory, chemical, tactile, and electrical signals

25. Chemical Communication • Pheromones

26. (a) Minnows are widely dispersed in an aquarium before an alarm substance is introduced. (b) Within seconds of the alarm substance being introduced, minnows aggregate near thebottom of the aquarium and reduce their movement. Figure 51.9a, b • When a minnow or catfish is injured • An alarm substance in the fish’s skin disperses in the water, inducing a fright response among fish in the area

27. Volley period EXPERIMENT Charles Henry, Lucía Martínez, and ent Holsinger crossed males and females of Chrysoperla plorabunda and Chrysoperla johnsoni, two morphologically identical species of lacewings that sing different courtship songs. SONOGRAMSChrysoperla plorabunda parent Vibration volleys Standard repeating unit crossed with Chrysoperla johnsoni parent Volley period Standard repeating unit The researchers recorded and compared the songs of the male and female parents with those of the hybrid offspring that had been raised in isolation from other lacewings. Auditory Communication • Insect courtship songs (under genetic control)

28. Learning • Modification of behavior based on specific experiences

29. Habituation • Loss of responsiveness to stimuli that convey little or no information

30. Spatial Learning • Modification of behavior based on experience with the spatial structure of the environment

31. A female digger wasp excavates and cares for four or five separate underground nests, flying to each nest daily with food for the single larva in the nest. To test his hypothesis that the wasp uses visual landmarks to locate the nests, Niko Tinbergen marked one nest with a ring of pinecones. EXPERIMENT When the wasp returned, she flew to the center of the pinecone circle instead of to the nearby nest. Repeating the experiment with many wasps, Tinbergen obtained the same results. RESULTS Nest No Nest Nest The experiment supported the hypothesis that digger wasps use landmarks to keep track of their nests. CONCLUSION Figure 51.14 • Classic experiment • Showed how digger wasps use landmarks to find the entrances to their nests After the mother visited the nest and flew away, Tinbergen moved the pinecones a few feet to one side of the nest.

32. Before stimulus Influx of alarm substances Influx of water alone Influx of pike odor Day 1 Day 3 Relative activity level Experimentalgroup Control group Control group Experimental group • Classical conditioning • Arbitrary stimulus is associated with a reward or punishment Figure 51.15

33. Classical conditioning

35. Figure 51.16 • Operant conditioning • Animal learns to associate one of its behaviors with a reward or punishment, trial and error learning

36. Cognition and Problem Solving • Perceive, store, process, and use information gathered by sensory receptors

37. Figure 51.17 • Problem solving can be learned • By observing the behavior of other animals

38. (a) A garter snake (Thamnophis elegans) (b) A banana slug (Ariolimuscalifornicus); not to scale Figure 51.18a, b Variation in Prey Selection • Due to prey availability and are evidence of behavioral evolution

39. Desert grassland population 50 Riparian population 40 30 Time to attack (seconds) 20 10 0 Lab-raised generation 2 Lab-raised generation 1 Field Variation in Aggressive Behavior • Funnel spiders living in different habitats • Exhibit differing degrees of aggressiveness in defense and foraging behavior 60 Population Figure 51.19

40. N Adults from Britain and F1 offspring of British adults BRITAIN W E S (b) Wintering blackcaps captured in Britain and their laboratory-raised offspring had a migratory orientation toward the west, whileyoung birds from Germany were oriented toward the southwest. GERMANY N E W Youngfrom SW Germany S Mediterranean Sea Figure 51.21b • Migratory orientation of wintering adult birds captured in Britain • Evolution of behavior

41. Natural selection favors behaviors that increase survival and reproductive success

42. Foraging Behavior • Optimal foraging theory • Views foraging behavior as a compromise between the benefits of nutrition and the costs of obtaining food

43. Small prey at middle distance Small prey at close distance Large prey at far distance Small prey Small prey Small prey 33% 33% 33% 33% Medium prey Medium prey Medium prey Low prey density High prey density 33% 33% Large prey Large prey Large prey 14% 35% 50% Percentage available 100% Predicted percentage in diet 32.5% 2% 40% 32.5% 57% 35% Observed percentage in diet Figure 51.23 • Bluegill sunfish • Prey selection behavior is related to prey density

44. Mating Behavior and Mate Choice • Product of a form of natural selection call sexual selection

45. Eggs Figure 51.26 • Species w/ large numbers of offspring • Parental care carried out by males or females

46. Figure 51.27 • Mate Choice by Females • e.g. Male zebra finches more ornate than females, affects mate choice by the females

47. Figure 51.30 • Male comp. for mates • often ritualized contest

48. Many social behaviors are selfish • Natural selection favors behavior • That maximizes an individual’s survival and reproduction

49. Altruism • Behavior that reduces an individuals fitness but increase the fitness of others

50. Figure 51.33 • Naked mole rat populations • Nonreproductive individuals may sacrifice their lives protecting the reproductive individuals from predators