1. Chapter 51:
Animal Behavior
Mrs. Valdes
AP Biology

2. Overview: Shall We Dance?
Cranes: interesting dancing behavior during courtship
Animal behavior based on physiological systems and processes
Behavior: nervous system’s response to stimulus; carried out by muscular or hormonal system
Behavior helps animal
Obtain food
Find partner for sexual reproduction
Maintain homeostasis
Behavior subject to natural selection

3. Concept 51.1: Discrete sensory inputs can stimulate both simple and complex behaviors
Animal’s behavior = response to external and internal stimuli
Ethology: scientific study of animal behavior, particularly in natural environments
According to early ethologist Niko Tinbergen, four questions should be asked about behavior:
What stimulus elicits behavior, and what physiological mechanisms mediate response?
How does animal’s experience during growth and development influence response mechanisms?
How does behavior aid survival and reproduction?
What is behavior’s evolutionary history?
Proximate causation: “how” explanations, focus on
Environmental stimuli that trigger behavior
Genetic, physiological, and anatomical mechanisms underlying behavior
Ultimate causation: “why” explanations, focus on evolutionary significance of behavior
Behavioral ecology: study of ecological and evolutionary basis for animal behavior; integrates proximate and ultimate explanations for animal behavior

4. Fixed Action Patterns
DEFINE: sequence of unlearned, innate behaviors that is unchangeable
Once initiated carried to completion
triggered by external cue known as sign stimulus
Ex: male stickleback fish
Stimulus for attack behavior: red underside of intruder
Action: presented with unrealistic models, as long as some red is present, attack behavior occurs

5. Oriented Movement
Environmental cues can trigger movement in a particular direction
Kinesis: simple change in activity or turning rate in response to a stimulus
Ex: sow bugs become more active in dry areas and less active in humid areas
Sow bug behavior varies with humidity, sow bugs do NOT move toward or away from specific moisture levels
Taxis: more or less automatic, oriented movement toward or away from a stimulus
Ex: stream fish exhibit positive taxis and automatically swim in upstream direction
prevents them from being swept away and keeps them facing direction from which food will come

6. Migration DEFINE: regular, long-distance change in location
Animals can orient themselves using
position of sun and their circadian clock
position of North Star
Earth’s magnetic field

7. Behavioral Rhythms
Some animal behavior affected by animal’s circadian rhythm
Behaviors such as migration and reproduction are linked to changing seasons, or a circannual rhythm
Some behaviors linked to lunar cycles
Ex: courtship in fiddler crabs occurs during new and full moon

8. Animal Signals and Communication
Signal: behavior that causes change in another animal’s behavior
Communication: transmission and reception of signals
Animals communicate using visual, chemical, tactile, and auditory signals
Type of signal closely related to lifestyle and environment
Honeybees show complex communication with symbolic language
bee returning from field performs dance to communicate information about position of food source

9. Pheromones Pheromones: chemicals emitted through odors
effective at very low concentrations
Ex: minnow or catfish injured alarm substance in fish’s skin disperses in water induce fright response among fish in area

10. Concept 51.2: Learning establishes specific links between experience and behavior
Innate behavior: developmentally fixed; under strong genetic influence
Learning: modification of behavior based on specific experiences
Habituation: simple form of learning; involves loss of responsiveness to stimuli that convey little or no information
Ex:, birds stop responding to alarm calls from their species if not followed by actual attack
Imprinting: behavior that includes learning and innate components; generally irreversible
distinguished from other learning by sensitive period
limited developmental phase that is ONLY TIME when certain behaviors can be learned
Ex: young geese following their mother
Konrad Lorenz showed when baby geese spent first few hours of life with him imprinted on him as parent
Conservation biologists taken advantage of imprinting in programs to save whooping crane from extinction
Young whooping cranes imprint on humans in “crane suits” who lead crane migrations using ultralight aircraft

11. Spatial Learning
Spatial learning: more complex modification of behavior based on experience with spatial structure of environment
Niko Tinbergen showed how digger wasps use landmarks to find nest entrances
Cognitive map: internal representation of spatial relationships between objects in animal’s surroundings
Ex: Clark’s nutcrackers can find food hidden in caches located halfway between particular landmarks

12. Associative Learning
DEFINE: animals associate one feature of environment with another
Ex: white-footed mouse avoid eating caterpillars with specific colors after bad experience with distasteful monarch butterfly caterpillar
Classical conditioning: type of associative learning in which arbitrary stimulus associated with reward or punishment
Ex: dog repeatedly hears bell before being fed  salivate in anticipation at bell’s sound
Operant conditioning: type of associative learning in which animal learns to associate one of its behaviors with a reward or punishment
also called trial-and-error learning
Ex: rat that fed after pushing lever will learn to push lever in order to receive food
Ex: predator learn to avoid specific type of prey associated with painful experience

13. Cognition and Problem Solving
Cognition: process of knowing that includes awareness, reasoning, recollection, and judgment
Ex: honeybees can distinguish “same” from “different”
Problem solving: process of devising strategy to overcome obstacle
Ex: chimpanzees stack boxes in order to reach suspended food
Some animals learn to solve problems by observing other individuals
Ex: young chimpanzees learn to crack palm nuts with stones by copying older chimpanzees

14. Learning and problem solving
Fig. 51-UN1
Imprinting
Learning and
problem solving
Spatial learning
Cognition
Associative learning
Social learning

15. Concept 51.3: Both genetic makeup and environment contribute to the development of behaviors
Animal behavior governed by complex interactions between genetic and environmental factors
Cross-fostering studies help behavioral ecologists identify contribution of environment to animal’s behavior
Cross-fostering study: places young from one species in care of adults from another species
California mice and white-footed mice study uncovered influence of social environment on aggressive and parental behaviors
Cross-fostered mice developed some behaviors that were consistent with their foster parents
Humans: twin studies allow researchers to compare relative influences of genetics and environment on behavior

16. Regulatory Genes and Behavior
Master regulatory gene can control many behaviors
Ex: single gene controls many behaviors of male fruit fly courtship ritual
Multiple independent genes can contribute to a single behavior
Ex: Green lacewings: courtship song unique to each species; multiple independent genes govern different components of courtship song

17. Genetically Based Behavioral Variation in Natural Populations
Behavioral variation within species corresponds to environmental variation evidence of past evolution
Example: Most blackcaps (birds) that breed in Germany winter in Africa, but some winter in Britain
two migratory populations are genetically distinct
Example: Natural diet of western garter snakes varies by population
Coastal populations feed mostly on banana slugs, while inland populations rarely eat banana slugs
Studies show differences in diet are genetic
two populations differ in ability to detect and respond to specific odor molecules produced by banana slugs!

18. Influence of Single-Locus Variation
Differences at single locus can sometimes have a large effect on behavior
Ex: male prairie voles pair-bond with their mates, while male meadow voles do not
level of specific receptor for neurotransmitter determines which behavioral pattern develops

19. Concept 51.4: Selection for individual survival and reproductive success can explain most behaviors
Genetic components of behavior evolve through NATURAL SELECTION!!!!!
Behavior can affect fitness by influencing foraging and mate choice
Natural selection refines behaviors that enhance efficiency of feeding
Foraging: food-obtaining behavior; includes recognizing, searching for, capturing, and eating food items
Drosophila melanogaster, variation in gene dictates foraging behavior in larvae
Larvae with one allele travel farther while foraging than larvae with other allele
Larvae in high-density populations benefit from foraging farther for food
Larvae in low-density populations benefit from short-distance foraging
Natural selection favors different foraging behavior depending density of the population

20. Optimal Foraging Model
Optimal foraging model: views foraging behavior as compromise between benefits of nutrition and costs of obtaining food
costs of obtaining food include energy expenditure and risk of being eaten while foraging
Natural selection should favor foraging behavior that minimizes costs and maximizes benefits
Optimal foraging behavior demonstrated by Northwestern crow
crow will drop whelk (a mollusc) from height to break shell and feed on soft parts
crow faces trade-off between height from which it drops whelk and number of times it must drop whelk
Researchers determined experimentally that total flight height (which reflects total energy expenditure) minimized at drop height of 5 m AND…
average flight height for crows is 5.2 m. BOOM. SCIENCE.

21. Average number of drops
Fig
125 60 50
100 40
Average number of drops
Average number of drops 30 75
Total flight height (number of drops  drop height in m)
Total flight height 20
Drop height
preferred
by crows = 5.23 m 50
Figure Energy costs and benefits in foraging behavior 10 25 2 3 5 7 15
Drop height (m)

22. Mating Behavior and Mate Choice
Mating behavior includes seeking or attracting mates, choosing among potential mates, and competing for mates
Mating behavior results from type of natural selection called sexual selection
Promiscuous: no strong pair-bonds or lasting relationships; many animals
Monogamous relationships: one male mates with one female
Males and females with monogamous mating systems have similar external morphologies
Polygamous relationships: individual of one sex mates with several individuals of other sex; species usually sexually dimorphic: males and females have different external morphologies
Polygyny: one male mates with many females
Males usually more showy and larger than females
Polyandry: one female mates with many males; RARE
Females often more showy than males

23. Paternal certainty relatively low species with internal fertilization
Needs of young important factor constraining evolution of mating systems
Ex: Bird species chicks need continuous supply of food
A male maximizes his reproductive success by staying with his mate, and caring for his chicks (monogamy)
Ex: Bird species chicks soon able to feed and care for self
A male maximizes his reproductive success by seeking additional mates (polygyny)
Females certain eggs laid / young born contain her genes; however, paternal certainty depends on mating behavior
Paternity certainty influences parental care and mating behavior
Paternal certainty relatively low species with internal fertilization
mating and birth separated over time
Paternal certainty much higher when egg laying and mating occur together, as in external fertilization
parental care is at least as likely to be by males as by females

24. Sexual Selection and Mate Choice
Intersexual selection: members of one sex choose mates on basis of certain traits
Female Choice
Intrasexual selection: involves competition between members of same sex for mates
Mate Choice by Females
Females drive sexual selection by choosing males with specific behaviors or features of anatomy
Ex: female stalk-eyed flies choose males with relatively long eyestalks
Ornaments, such as long eyestalks, often correlate with health and vitality
Ex: Female zebra finch chicks who imprint on ornamented fathers are more likely to select ornamented mates
Experiments suggest mate choice by female zebra finches play key role in evolution of ornamentation in male zebra finches

25. Experimental Groups of Parental Pairs Control Group
Fig
Experimental Groups of Parental Pairs
Control Group
Both parents
ornamented
Males
ornamented
Females
ornamented
Parents not
ornamented
Offspring
Offspring
Mate preference of female offspring:
ornamented male
Figure Sexual selection influenced by imprinting
Mate preference of female offspring:
none

26. Male Competition for Mates
source of intrasexual selection that can reduce variation among males
may involve agonistic behavior
often ritualized contest that determines which competitor gains access to resource (lady or land that lady likes)

27. Applying Game Theory
Sexual selection driven evolution of alternative mating behavior and morphology in males
Fitness of particular phenotype (behavior or morphology) depends on phenotypes of other individuals in population
Game theory: evaluates alternative strategies where outcome depends on each individual’s strategy and strategy of other individuals
Ex: each side-blotched lizard has blue, orange, or yellow throat
each color associated with specific strategy for obtaining mates
genetic basis to throat color and mating strategy
Like rock-paper-scissors, each strategy will outcompete one strategy, but be outcompeted by other strategy
THUS! success of each strategy depends on frequency of all of strategies;
THIS drives frequency-dependent selection

28. Concept 51.5: Inclusive fitness can account for the evolution of altruistic social behavior
Natural selection favors behavior that maximizes individual’s survival and reproduction
These behaviors are often selfish
Altruism:
Occasionally some animals behave in ways that reduce their individual fitness but increase fitness of others AKA selflessness
Ex: under threat from predator, individual Belding’s ground squirrel make alarm call to warn others, even though calling increases chances that caller is killed
Ex: naked mole rat populations, nonreproductive individuals sacrifice lives protecting their reproductive queen and kings from predators

29. Inclusive Fitness Altruism explained by inclusive fitness
Inclusive fitness: total effect individual has on proliferating its genes by producing offspring and helping close relatives produce offspring

30. Hamilton’s Rule and Kin Selection
William Hamilton proposed quantitative measure for predicting when natural selection would favor altruistic acts among related individuals
Three key variables in altruistic act:
Benefit to recipient (B)
Cost to altruist (C)
Coefficient of relatedness (fraction of genes that, on average, are shared; r)
Natural selection favors altruism when:
rB > C
Hamilton’s rule: this inequality
Kin selection: natural selection that favors this kind of altruistic behavior by enhancing reproductive success of relatives
Ex: warning behavior in Belding’s ground squirrels
In group, most of females closely related to each other
Most alarm calls given by females who aiding close relatives
Ex: Naked mole rats living within colony are closely related
Nonreproductive individuals increase their inclusive fitness by helping reproductive queen and kings (their close relatives) to pass their genes to the next generation

31. Mean distance (m) moved from birthplace
Fig
300
Male
200
Mean distance (m)
moved from
birthplace
100
Figure Kin selection and altruism in Belding’s ground squirrels
Female 1 2 3 4 12 13 14 15 25 26
Age (months)

32. Reciprocal Altruism
Reciprocal altruism: altruistic behavior toward unrelated individuals can be adaptive if aided individual returns favor in future
limited to species with stable social groups where individuals meet repeatedly, and cheaters (who don’t reciprocate) are punished
used to explain altruism between unrelated individuals in humans

33. Social Learning
DEFINE: learning through observation of others and forms roots of culture
Culture: system of information transfer through observation or teaching that influences behavior of individuals in population
can alter behavior and influence fitness of individuals
Mate-choice copying: individuals in population copy mate choice of others
This type of behavior extensively studied in guppy Poecilia reticulata
Females who mate with males attractive to other females more likely to have sons that are attractive to other females
“Sexy Son” Hypothesis

34. Evolution and Human Culture
No other species comes close to matching social learning and cultural transmission that occurs among humans
Human culture related to evolutionary theory in distinct discipline of sociobiology
Human behavior results from interactions between genes and environment
However, social and cultural institutions may provide ONLY feature in which there is NO continuum between humans and other animals

35. You should now be able to:
State Tinbergen’s four questions and identify each as a proximate or ultimate causation
Distinguish between the following pairs of terms: kinesis and taxis, circadian and circannual behavioral rhythms, landmarks and cognitive maps, classical and operant conditioning
Suggest a proximate and an ultimate cause for imprinting in newly hatched geese
Explain how associative learning may help a predator avoid toxic prey
Describe how cross-fostering experiments help identify the relative importance of environmental and genetic factors in determining specific behaviors
Describe optimal foraging theory
Define and distinguish among promiscuous, monogamous, and polygamous mating systems
Describe how the certainty of paternity may influence the development of mating systems
Distinguish between intersexual and intrasexual selection
Explain how game theory may be used to evaluate alternative behavioral strategies
Define altruistic behavior and relate the coefficient of relatedness to the concept of altruism
Distinguish between kin selection and reciprocal altruism
Define social learning and culture