1. Chapter 51
Behavioral Biology
Video: Do Animals Have Morals?

2. Essential Knowledge
2.C.2 – Organisms respond to changes in their external environments
a. Organisms respond to changes in their environment through behavioral and physiological mechanisms
Ex: Taxis and kinesis, hibernation and migration, nocturnal and diurnal activity: circadian rhythms
2.E.2 – Timing and coordination of physiological events are regulated by multiple mechanisms
b. In animals, internal and external signals regulate a variety of physiological responses that synchronize with environmental cycles and cues
Circadian rhythms, diurnal/nocturnal cycles, hibernation, estivation, migration, pheromone release, visual displays in reproductive cycles

3. 2.E.3 – Timing and coordination of behavior are regulated by various mechanisms and are important in natural selection
a. Individuals can act on information and communicate it to others
1. Innate behaviors are behaviors that are inherited
2. Learning occurs through interactions with the environment and other organisms
b. Responses to information and communication of information are vital to natural selection
3. Behaviors in animals are triggered by environmental cues and are vital to reproduction, natural selection, and survival
Ex: hibernation, estivation, migration, courtship
4. Cooperative behaviors within or between populations contributes to the survival of the populations
Ex: niche and resource partitioning, mutualistic relationships

4. 3.E.1 – Individuals can act on information and communicate it to others
a. Organisms exchange information with each other in response to internal changes and external cues, which can change behavior
Ex: predator warnings, protection of young, avoidance responses
b. Communication occurs through various mechanisms
1. Living systems have a variety of signal behaviors or cues that produce changes in the behavior of other organisms and can result in differential reproductive success
Ex: territorial marking in mammals
2. Animals use visual, audible, tactile, electrical and chemical signals to indicate dominance, find food, establish territory and ensure reproductive success
Ex: bee dances, bird songs, territorial marking in mammals, pack behavior in animals, herd, flock and schooling behavior in animals, colony and swarming behavior in insects, predator warning

5. c. Responses to information and communication of information are vital to natural selection and evolution
1. Natural selection favors innate and learned behaviors that increase survival and reproductive fitness
Ex: parent and offspring interactions, migration patterns, courtship and mating behaviors, foraging in bees and other animals, avoidance behaviors to electric fences, poisons, or traps
2. Cooperative behavior tends to increase the fitness of the individual and the survival of the population
Ex: pack behavior in animals, herd, flock and schooling behavior in animals, predator warning, colony and swarming behavior in insects

6. What is behavior?
Behavior = a response to internal and external stimuli from an animal’s environment and includes actions carried out by muscles under the control of the nervous system
Innate: behaviors that are developmentally fixed and are common among all members of a population
Genetically inherited, “instinctive”, automatic and consistent
Learned: behaviors that are influenced by an animal’s environment as a result of specific experiences
Ability to learn is inherited, but the behavior develops during an animal’s lifetime
Variable and flexible – changes with experience and environment

7. Ethology
Ethology = study of behavior and its relationship to its evolutionary origins
Pioneers in ethology: received a shared Nobel Prize in 1973
Karl von Frisch – waggle dance communication
Nikolaas Tinbergen – fixed action pattern and supernormal stimulus
Konrad Lorenz - imprinting

9. Why study behavior? Evolutionary perspective…
Behaviors are part of an animal’s phenotype
Acted upon by natural selection which can lead to:
greater fitness, survival, and reproductive success

10. Understanding any behavior requires answering 4 questions:
What stimulus elicits the behavior, and what physiological mechanisms mediate the response?
How does the animal’s experiences during growth and development influence the responses?
How does the behavior make the animal more likely to survive and reproduce?
What is the behavior’s evolutionary history?
First two questions ask about proximate causes of behavior (how) and the second two questions ask about the ultimate causes of behavior (why)

11. Proximate causes
Immediate, physiological, genetic, neurological, and developmental mechanisms that determine how an individual behaves
How and What questions
Male songbird
What triggers singing?
How does he sing?
Ultimately leads to the ultimate cause of WHY does he sing?

12. Ultimate causes
Results from the evolutionary pressures that have shaped the animal’s behavior (evolutionary significance of the behavior)
How does behavior contribute to survival and reproduction – adaptive value
Why questions
Courtship behaviors in Sandhill Cranes:
How does day length influence breeding?
Why do cranes breed in spring?

13. Examples of the two main types of behaviors: innate and learned

14. Innate Behaviors
Fixed action patterns (FAP): sequence of acts essentially unchangeable and carried to completion once started
Sign stimulus (releasers): external sensory stimulus that triggers the FAP
Ex: 3-spined stickleback (Tinbergen), egg rolling in geese, gull chicks respond to red dot on their parent’s bills to get food
Do humans have Fixed Action Patterns?
- The eyebrow flash – unconscious social signal: when you greet someone you will raise your eyebrows for a fraction of a second

15. Stickleback fish
Egg rolling

16. Innate behaviors
Supernormal stimulus: responding more to a larger sign stimulus
Ex: larger egg of a different species given to oyster catcher and bird will abandon their eggs to care for the larger
Does lipstick create a supernormal stimulus in humans?

18. Innate: Directed movements
Taxis: Automatic movement toward or away from a stimulus
Meaning: to arrange
Ex: Fish orienting themselves upstream toward the current
Kinesis: Change in rate of movement in response to a stimulus
Ex: Change in humidity causes sow bugs (roly-polies or pill bugs) to move when dry and rest when humid, scattering of cockroaches when lights are turned on

19. Complex Innate Behaviors
Migration: using environmental cues to create a regular, long-distance change in location
Completed by a wide variety of animals
Navigation might be dictated by earth’s magnetic field, position relative to the sun (circadian rhythms), and nocturnal animals use the North Star
“Migratory restlessness” seen in birds bred and raised in captivity

20. Behavior Rhythms
Circadian rhythm or clock – internal mechanisms that maintains a 24-hour activity rhythm (daily activity cycle in animals)
If mammals are kept in constant conditions, its circadian clock will run according to its natural period (genetic control) and be coordinated with light and dark cycles
Brain releases hormones that regulate night and dark cycle
If conditions are not held constant in an artificial environment, scientists can induce out-of-season migratory behaviors

21. Behavioral rhythms can be linked to yearly or seasonal changes as well that will influence migration and reproduction
Ex: Male fiddler crab claw waving to get a mate is linked to the cycles of the moon, estivation (sleep in hot, dry summer months) and hibernation (sleep in cold winter months) occurs in response to changing environmental conditions
Circadian rhythms were restored experimentally with transplanted neural tissue, and recipients know rhythms of the donor tissue

22. Example of Changes over 24-hours

23. Animal Signals and Communication
Communication: the transmission through signals/stimuli and reception of those signals between animals (proximate cause of behavior)
Examples:
Courtship behaviors in fruit flies use 4 common modes of communication: visual, chemical, tactile, and auditory
Communication by song
Bird songs – species identification, mating rituals
Mixed learned and innate
Insect songs – mating rituals and song
Innate, genetically controlled

24. Waggle Dance Honeybee communication
Waggle dance: behavior that communicates the location and distance of a food source for foraging purposes
Foraging = food-obtaining behavior
Another example: Oyster catchers (shore bird) teach young for hours how to open an oyster by opening and closing the same oyster
Waggle Dance

25. Animal Signals and Communication
Pheromones: chemical signals (odor or taste) that are emitted from an individual to stimulate a response from other individuals
Alarm pheromones
Sex pheromones
Ex: female mosquito use CO2 concentrations to locate victims, spider uses moth pheromones to lure prey, marking territory, termites follow pheromone trails, Honey bee queen releases pheromones to maintain the complex social order of the hive

26. Learned behaviors
Imprinting: Learning to form social attachments at a specific critical period
Ex: Greylag geese and Konrad Lorenz
I’m not ready for kids!
Imprinting

27. Critical Period: sensitive phase for optimal imprinting
Some behavior must be learned during a receptive time period
Bird songs learning involves genetics, imprinting, and hormonal control
If a bird is deafened before starting to sing, it will not the develop species-specific song
Do humans imprint or have a critical period?
- Don’t imprint but do have a critical period for attachment for proper development to occur

28. Learned behavior
Spatial learning: establishment of a memory that reflects the environment’s spatial structure
Ex: Tinbergen digger wasps 1932, gray whales finding their way from Mexico to the Bering Sea
Homing – ability to return to a specific location from long distances
Ex: Female sea turtles return to shore they were hatched from , pigeons navigate by Earth’s magnetic field

30. Learned behavior
Associative learning: ability to associate one environmental factor with another or making associations between experiences
Operant conditioning (trial and error)
Learning process when behavior is associated with a consequence such as a reward or punishment
Classical conditioning
Learning process when two stimuli are repeatedly paired
A response (salivation) is at first elicited by a unconditioned stimulus (sight of food) but then paired with a conditioned stimulus (sound of bell) instead

31. Operant conditioning Skinner box
Mouse learns to associate behavior (pressing lever) with reward (food pellet)

32. Classical conditioning
Ivan Pavlov’s dogs
Connect reflex behavior (salivating at sight of food) to associated stimulus (ringing bell)

33. Learned behavior
Habituation: decrease or loss of a response to a repeated stimulus
Simplest form of learning: “cry-wolf” effect
Enables animals to disregard unimportant stimuli
Ex: Falling leaves not triggering fear response in baby birds

34. Learned behavior
Cognition: process of knowing represented by awareness, reasoning, recollection, and judgment
Problem-solving
Do you think other animals reason?

35. Social behaviors Agonistic behavior
Aggressive behavior determining access to resources
Threatening and submissive rituals
Symbolic, usually no harm done
Territorial behavior
An area an individual aggressively defends to exclude others
Use agonistic behaviors to achieve this

36. Social behaviors Dominance hierarchy
Linear “pecking order” that determines social ranking within a group
Mating behaviors and Mate choice:
Includes mating rituals, whether the animals are monogamous or polygamous, and the extent of parental care

37. Mating Choices:
Promiscuous – no strong pair bonds
Monogamous – one male/one female
Polygamous – one with many
Polygyny – one male/many females
Polyandry – one female/many males
Polygamous species can lead to sexual dimorphism = differences between the sexes

38. Social behavior Cooperation Working together in coordination
Ex: pack of wolfs hunting in a pack, whales “herding” schools of fish

39. Social behavior Altruistic behavior (Altruism) Kin selection
Reduces an individual’s reproductive fitness, but increase the fitness of others in the population
Kin selection
Increasing survival of close relatives will help to pass those genes on to the next generation
Ex: Mole rat, Belding’s ground squirrel, honeybees where worker females share 75% of the same genes

40. Summary: What determines behavior?
Genetics
Developmental processes
Physiological mechanisms
Shaped by natural selection
Social concerns

41. Behaviors and Genetic Determinants
Breeding experiments can reveal whether a behavioral phenotype is inherited
Studying mutants can reveal the role of specific genes
Knockout experiments in mice: some mice lack a receptor for pheromones and are unable to distinguish males from females
What implications does that have?

42. Evolutionary perspective
Adaptive advantages:
Innate behaviors
Automatic, fixed, “built-in”, no learning curve
Despite different environments, all individuals exhibit the behavior
Ex: early survival, reproduction, kinesis, taxis
Learned behaviors
Modified by experience
Flexible with a complex and changing environment which can lead to an increase in survival

43. Developmental Processes Shape Behavior
Development and expression of behavior can be controlled by hormones (small chemical messengers in the body)
Some behaviors can be acquired only at certain times

44. Physiological Mechanisms Underlie Behavior
Biological rhythms coordinate behavior with environmental cycles
Animals must find their way around their environment
Animals use multiple modalities to communicate

45. Behavior is Shaped by Natural Selection
Cost-benefit approach
Energetic cost – expending energy to do the behavior
Risk cost – chance of being injured or killed to perform the behavior
Opportunity cost – benefit forfeited by not performing the behavior

46. Social behaviors Interactions between individuals
Develop as evolutionary adaptations
Communication / language
Agonistic behaviors
Dominance hierarchy
Territoriality
Cooperation
Altruistic behavior