Behavioral Biology Chapter 51. Behavior is what an animal does and how it does it. What is Behavior?

Behavioral BiologyChapter 51

• Behavior is what an animal does and how it does it.

What is Behavior?

Ecology:Interaction between organisms and the biotic and

abiotic environment• Abiotic- non living; e.g., temperature, light,

dissolved gas, water• Biotic- living; e.g., predators, prey, mates

Behavioral EcologyThe study of the behavior of organisms within an

evolutionary framework.• e.g., communication, finding food,

protection from predators

Mechanistic basis for behavior:E.g., MIGRATIONA. Identify the stimuli that triggers the behavior or B. Study the psychological, neuronal, and

hormonal changes that underlie the behavior

Proximate causes• External stimuli- changes in day length and

temp• Internal stimuli - hormone levels

Ultimate causes - address the evolutionary significance for a behavior and why natural selection favors this behavior.

• Why did a behavior evolve?

• Is it adaptive?

• Does it contribute to reproductive success?

Example: birds that migrate have a selective advantage over birds that don't/didn't, selected for over time, could be due to long term climate changes, glaciation, disease, taking advantage of food sources, etc.

Nature versus Nurture:Revisiting an Old DebateNature

Behaviors are: • Innate • Hard-wired • Instinctual • Genetically

determined

Nurture

Behaviors are: • Learned • Flexible • Not genetically

determined

Behavior results from both genes and environmental factors

A. Behavior - What an animal does and how it does it.- some behavior is learned, some behavior is

inherited

B. To some extent ALL behavior has a Genetic Basis

1. some is totally genetic - which implies heritable2. some is learned but relies ENTIRELY on

genetically based mechanisms

C. In general, behavior is a response to some environmental stimulus

Innate Behaviors – inherited, instinctiveA. programmed by genes; B. highly stereotyped (similar each time in many individuals)C. Four Categories

1. Kinesis2. Taxis3. Reflex4. Fixed Action Pattern

1. Kinesis: "change the speed of random movement in response to environmental stimulus“

2. Taxis: "a directed movement toward or away from a stimulus; positive and negative taxes

3. Reflex: "movement of a body part in response to stimulus".

4. Fixed Action Pattern (FAP): "stereotyped and often complex series of movements, responses to a specific stimulus", hardwired, however, not purely genetic, may improve with experiencea. programmed response to a stimulusb. stimulus of FAP = "releaser", sometimes called "sign

stimulus“c. examples:

- courtship behavior- rhythms - daily (circadian); annual

(circannual)

D. Characteristics of Innate Behaviors - especially FAPs:

1. The behavior is performed correctly the 1st time without prior experience (no opportunity to learn)

2. Triggered by some external stimulus 3. Once started, run to completion with no

further input4. Breeding crosses produce hybrid behaviors

• Ethology is the study of how animals behave in their natural habitat.

– Karl von Frisch: bee communication

– Niko Tinbergen: herring gull experiment; digger wasps

– Konrad Lorenz: imprint in geese

Classical ethology presaged an evolutionary approach to

behavioral biology

Karl Von Frisch- communication in bees

Herring gull experiment by Niko Tinbergen

Releaser Stimuli- stimuli that release FAPE.g., Chick and red dot on gull parents beak triggers feeding response- parent regurgitates food

Laysan albatross feeding chick

Niko Tinbergen

Hypothesis: digger wasps use visual landmarks to keep track of her nests

Move pine cones

Visual cue is arrangement pattern rather than objects themselves

Egg rolling behavior in geese is a Fixed Action Pattern

Male three-spined stickleback shows aggression at models with red undersides

Life-like model

• Songbird repertoiresprovide us withexamples.

– Why has naturalselection favoreda multi-songbehavior?

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Fig. 51.5

• It may be advantageous for males attracting females.


Fig. 51.6

• Cost-benefit analysis of foraging behavior.

– Foraging is food-obtaining behavior.• The optimal foraging theory states that natural

selection will benefit animals that maximize their energy intake-to-expenditure ratio.

Height ofDrop (m)

Average NumberOf Drops Required

to Break Shell

Total Flight Height(Number of Drops

Height per Drop)

2 55 110

3 13 39

5 6 30

7 5 35

15 4 60


Fig. 51.7

• The behavior is adaptive - signs that natural selection is at worka. survival may depend on behavior, learning not an option (one chance only)

b. animals with simple NS may not have capacity to learn

- not strictly true, "simple" animals learn

c. social interactions dependent on survival require rigid performance of roles

mating rituals, termite mounds

Learning - Learned Behavior: Five Categories

A. Imprinting

1. a strong association learned during a specific developmental period

a. "sensitive period" or "critical period"b. imprinting of baby geese on mother - Lorenz

baby geese imprint on mother within hours of hatchingwill imprint on any object during that period

2. learning a releaser for an innate FAP

Goose imprinting by Conrad LorenzGeese imprint on the first moving (with sound) object that they see after birthThere is a selection of a specific period of time (critical period) for social attachment and mate recognition in geese (to ensure geese imprint on the same species)

Imprinting in conservation biology:Need to minimize/eliminate human presence while raising California Condors

B. Habituation

1. decline in response to a harmless, repeated stimulus

filter - prevents animal from wasting energy/attention on irrelevant stimuliadaptive

C. Conditioning - laboratory setting

1. classical conditioning animals make associations - Pavlov's dog associates bell with food, begins to salivate, can be extinguished and later followed by recovery (unconditioned stimulus - meat, unconditioned response - salivation, conditioned stimulus - bell, conditioned response - salivation)

a. animal learns to perform an "old" response to a new stimulus

b. Pavlov's dog- place dried meat powder in dog mouth - salivation- associate with bell - salivation to bell

c. Stimulus first, behavior second (but of course there is an expectation of reward second)

2. operant conditioning a. perform behavior to receive reward or avoid punishment

b. Skinner Box - levers, reward - self training elaborate protocolsc. behavior first, reward second (but of course there is a stimulus, if only a thought of reward)

• Operant conditioning.

– This is called trial-and-error learning - an animal learns to associate one of its own behaviors with a reward or a punishment.

D. Trial and Error Learning - nature setting

1. natural operant conditioning2. modify responses to specific stimuli (releasers) - making both more adaptive3. modify releaser to specific FAP - making both more adaptive

Observational learning - social imitation

Octopus opening jar with crab

Trial & Error & Observational Learning

• Play as a behavior has no apparent external goal, but may facilitate social development or practice of certain behaviors and provide exercise.

Practice and exercise may explain the ultimate bases of play

E. Insight, reasoning

1. manipulating concepts in the mind to arrive at adaptive behavior

2. mental trial-and-error

3. internal memory stores are used as additional sensory/information source

All examples of tool-using:

• chickadees/tits and opening milk bottles

• Egyptian Vulture - uses rocks

• Cocos Finch - uses splinters of wood

• North American Gulls, Northwestern Crow - smash clams on sandy beaches

• Cognition is the ability of an animal’s nervous system to perceive, store, process, anduse information gatheredby sensory receptors.

The study of cognition connects nervous system function with behavior

• Kinesis and taxis.– These are the simplest mechanisms of

movement.• Kinesis is a change in activity rate in response to

a stimulus.– For example, sowbugs are more active in dry areas and less

active in humid areas.

• Taxis is an automatic, oriented movement to or away from a stimulus.– For example, phototaxis, chemotaxis, and geotaxis.

Animals use various cognitive mechanisms during movement through space


• Use of landmarks within a familiar area.

– Some organisms move in response to a recognized object or environmental cue, the object is the landmark.

• Cognitive maps.

– Some animals form cognitive maps (internal codes of spatial relationships of objects in the environment).


• Migration Behavior.

– Migration is theregular movementof animals overrelatively longdistances.

– Piloting: an animalmoves from onefamiliar landmarkto another until itreaches its destination.

Whale Migration Routes

• Orientation: animals can detect directions and travel in particular paths until reaching destination.– Navigation is the most complex, and involves

determining one’s present location relative to other locations in addition to detecting compass directions.

– Cues for thesebehaviors includethe earth’s magnetic field, the sun, and the stars.

• Besides humans, are animals aware of themselves?

• Some wouldargue thatcertain behaviorsare a result ofconsciousprocessing.

The study of consciousness poses a unique challenge for scientists

• Social behavior is any kind of interaction between two or more animals, usually of the same species.

Sociobiology places social behavior in an evolutionary context


Social Behavior in VertebratesA. Predator Avoidance Behavior-mimicry- schoolingB. Reproductive Behavior-competition

-territoriality- displaysC. Parental BehaviorD. CommunicationE. Cooperative Behavior-warning alarms

• Sometimescooperation occurs.

Competitive social behaviors often represent contests for resources


Fig. 51.18

• Agonistic behavior is a contest involving threats.

– Submissive behavior.

– Ritual: the use of symbolic activity.

– Generally, no harm is done.


Fig. 51.19

• Reconciliation behavior often happens between conflicting individuals.


Fig. 51.20

• Dominance hierarchies involve a ranking of individuals in a group (a “pecking order”).

– Alpha, beta rankings exist.• The alpha organisms control the behavior of

others.


• Territoriality is behavior where an individual defends a particular area, called the territory.

– Territories are typically used for feeding, mating, and rearing young and are fixed in location.

– Drawbacks are that territoriality uses a great deal of an individual’s energy.• In addition, an individual might be defending a

territory and die or miss a reproductive opportunity.

– Spraying behavior is where an individual marks its territory.

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin CummingsFig. 51.22

• Courtship behavior consists of patterns that lead to copulation and consists of a series of displays and movements by the male or female.

Natural selection favors mating behavior that maximizes the quantity

or quality of mating partners



Fig. 51.23

• Parental investment refers to the time and resources expended for raising of offspring.– It is generally lower in males

– Females usually invest more time into parenting (fecundity, egg size, care of offspring)

– Females are usually more discriminating in terms of the males with whom they choose to mate.• Females look for more fit males (i.e., better genes),

the ultimate cause of the choice.


• Mating systems differ among species.– Promiscuous: no strong bond pairs

between males and females.

– Monogamous: one male mating with one female.

– Polygamous: an individual of one sex mating with several of the other sex.• Polygyny is a specific example of polygamy,

where a single male mates with many females.

• Polyandry occurs in some species where one female mates with several females.


• Certainty of paternity can influence mating systems and parental care.

– If the male isunsure if offspringare his, parentalinvestment islikely to be lower.

– Exceptions doexist.

Male sea spider cares for eggs

Mimicry

monarch viceroy

Bastian Mimicry- palatable species resembles an unpalatable one

Mullerian- two or more unpalatable species resembles one another

monarch queen

blenny (Aspidontus taeniatus) mimics Hawaiian cleaner wrasse

shortnose wrasse mimics Potter's angel which sports a defensive spine

Mimicry

Schooling Behavior

• Defining animal signals and communication.– A signal is a behavior that causes a change

in the behavior of another animal.

– The transmission of, reception of, and response to signals make up communication.

– Examples include the following:• Displays such as singing, and howling.

• Information can be transmitted in other ways, such as chemical, tactile, electrical.

Social interactions depend on diverse modes of communication


– Pheromones are chemicals released by an individual that bring about mating and other behaviors.• Examples include bees and ants.


Fig. 51.26

• Most social behaviors are selfish, so how do we account for behaviors that help others?– Altruism is defined

as behavior that mightdecrease individual fitness, but increase the fitness of others.

The concept of inclusive fitness can account for most altruistic behavior


Fig. 51.28


Fig. 51.29

– Inclusive fitness: How can a naked mole rat enhance its fitness by helping other members of the population?• How is altruistic behavior maintained by

evolution?• If related individuals help each other, they

are in affect helping keep their own genes in the population.

• Inclusive fitness is defined as the affect an individual has on proliferating its own genes by reproducing and helping relatives raise offspring.


– Hamilton’s Rule and kin selection.• William Hamilton proposed a quantitative

measure for predicting when natural selection would favor altruistic acts.

• Hamilton’s rule states that natural selection favors altruistic acts.


• The three key variables are as follows:– B is the benefit to the

recipient– C is the cost to the

altruist– r is the coefficient of

relatedness, which equals the probability that a particular gene present in one individual will also be inherited from a common parent or ancestor in a second individual


Fig. 51.30

– The rule is as follows:• rB > C• The more closely related two individuals are,

the greater the value of altruism.


– Kin selection is the mechanism of inclusive fitness, where individuals help relatives raise young.

– Reciprocal altruism, where an individual aids other unrelated individuals without any benefit, is rare, but sometimes seen in primates (often in humans).

Sociobiology connects evolutionary theory to human culture


Fig. 51.32

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Behavioral Biology Chapter 51. Behavior is what an animal does and how it does it. What is Behavior?