Chapter 51Chapter 51

Behavioral EcologyBehavioral Ecology

I. Proximate and Ultimate BehaviorI. Proximate and Ultimate Behavior

Elements of behaviorElements of behavior

Proximate vs. UltimateProximate vs. Ultimate

EthologyEthology– Fixed-Action Patterns (FAP)Fixed-Action Patterns (FAP)

Sign stimulusSign stimulus

– ImprintingImprintingSensitive periodSensitive period

Figure 51-03

LE 51-4

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 decreases the chance that eggs laid in his nesting territory will be fertilized by another male.

LE 51-5

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 51-06

II. Genetic ComponentII. Genetic Component

Directed movementDirected movement– KinesisKinesis– TaxisTaxis– MigrationMigration

Animal signals and communicationAnimal signals and communication– ChemicalChemical– AuditoryAuditory– VisualVisual

LE 51-7a

Kinesis increases the chance that a sow bug will encounter and stayin a moist environment.

Dry openarea

Moist siteunder leaf

LE 51-7b

Positive rheotaxis keeps trout facing into the current, the directionfrom which most food comes.

Directionof rivercurrent

Figure 51-08

LE 51-9

Minnows are widely dispersed in an aquarium before an alarm substance is introduced.

Within seconds of the alarm substance being introduced, minnows aggregate near the bottom of the aquarium and reduce their movement.

Mating and ParentingMating and Parenting– Prarie volesPrarie voles– AVP – arginine-vasopressinAVP – arginine-vasopressin

Table 51-1

III. Environmental InfluenceIII. Environmental Influence

Diet and mate selectionDiet and mate selectionSocial learning and aggressive behaviorSocial learning and aggressive behaviorLearningLearning– HabituationHabituation– Spatial learningSpatial learning– Cognitive mapsCognitive maps– Associative learningAssociative learning

Classical conditioningClassical conditioningOperant conditioningOperant conditioning

Figure 51-16

IV. Behavior and Natural SelectionIV. Behavior and Natural Selection

Variations existVariations exist

Natural selection favors behaviors that Natural selection favors behaviors that increase fitnessincrease fitness– ForagingForaging– Mating behaviors and mate choiceMating behaviors and mate choice

LE 51-22

Average number of drops

Total flight height

Drop heightpreferredby crows = 5.23 m

Ave

rag

e n

um

be

r o

f d

rop

s

125

100

75

50

25

Height of drop (m)

60

50

40

30

20

10

015532 7

To

tal f

l igh

t h

eig

ht

(nu

mb

er o

f d

rop

s

dro

p h

ei g

ht

in m

)

LE 51-25

Since monogamous species, such as these trumpeter swans, are often monomorphic, males and females are difficult to distinguish using external characteristics only.

Among polygynous species, such as elk, the male (left) is often highly ornamented.

In polyandrous species, such as these Wilson’s phalaropes, females (top) are generally more ornamented than males.

LE 51-28

Females reared by ornamented parents or ornamented fathers preferred ornamented males as mates.

Females reared by ornamented mothers or nonornamented parents showed no preference for either ornamented or nonornamented males.

Males reared by all experimental groups showed no preference for either ornamented or nonornamented female mates.

Experimental Groups

Results

Both parentsornamented

Malesornamented

Femalesornamented

Parents notornamented

Control Group

Figure 51-30

V. Inclusive fitnessV. Inclusive fitness

AltruismAltruism

Inclusive fitnessInclusive fitness– Hamilton’s rule and kin selectionHamilton’s rule and kin selection– Reciprocal altruismReciprocal altruism

Figure 51-37