Behavioral EcologyChapter 51

A. P. Biology

Liberty Senior High School

Mr. Knowles

Why study animal behavior?

Understand

• Human nervous system.

• Child development.

• Human communication.

• Natural selection.

Animal Behavior • Behavior- a way an organism responds to

stimuli in its environment.

• Two Parts:

The How?- hormone levels, nerve impulses and pathways-Proximate Causation.

The Why?- adaptive value to animal’s survival or reproductive success- Ultimate Causation.

What’s the difference between stimulus and response?

• Stimulus- some environmental change or factor that can be perceived by a sense.

• Response- an organism’s reaction to an environmental change.

Ethology• Study of natural history of

behavior.• Early ethologist, like Konrad

Lorenz and Niko Tinbergen, believed behavior was based on instinct- innate.

• Example: Egg Retrieval in Geese Insect--> Frog’s Tongue

Viewed Behavior in 3 Parts• Sign Stimulus- appearance of some

signal.

• Innate Releasing Mechanism- sensory mechanism that detects the signal.

• Fixed Action Pattern- stereotyped act or behavior.

Show Me Egg Retrieval!

Nature: Triumph of Life- Brain Power movie

What a sign stimulus!

Innate Behaviors• Determined by the genes of an

organism.• Evidence: Behavioral genetics of

Robert Tryon, 1940’s with rats and mazes Selected for fastest rats, after 7 generations, maze time was 1/2 the average.

• Drosophila: mutant males fail to disengage females during mating. Also, courtship songs of birds are genetic.

Migration• Many features of migratory behavior in birds

– Have been found to be genetically programmed

Figure 51.8

Comparative Psychologists• Behavior was due to learning.• Learning- any modification of behavior

that results from experience rather than maturation.

• Two Kinds:1. Nonassociative Learning: animal

forms no association between stimulus and response (habituation = no +/- reinforcement). Ex. Young birds in nest.

Learning2. Associative Learning- behavioral alteration that involves an association between stimulus and response. The behavior is modified or conditioned (classical conditioning).

Example: Young predators learning to identify acceptable prey.

Poisonous Coral Snake or Harmless Milk Snake?

Classical conditioning is a type of associative learning– In which an arbitrary stimulus is associated with a

reward or punishment

Figure 51.15

Before stimulus

Influx of water alone

Influx of alarm substances

Influx of pike odor

Day 1Day 3

Control group Control groupExperimental

groupExperimental

group

Rel

ativ

e ac

tivi

ty le

vel

What human behaviors are learned? innate?

Show me the video!

Nova: Secrets of the Wild Child

Spatial Learning

• Spatial learning is the modification of behavior– Based on experience with the spatial

structure of the environment.

• In a classic experiment, Niko Tinbergen

– 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.

Figure 51.14CONCLUSION

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

Nest

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

The experiment supported the hypothesis that digger wasps use landmarks to keep track of their nests.

NestNo Nest

Problem solving can be learned:

-by observing the behavior of other animals.

Figure 51.17

Can an animal learn anything?

• Learning Preparedness- what an animal can learn is genetically determined; learning limited by instinct. Adaptive benefit.

• Example: rats can associate food by smell rather than by color.

pigeons associate food by color rather than sound.

Brook Stickleback

Figure 51.3a

(a) A male three-spined stickleback fish shows its red underside.

Figure 51.3b

(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 51.4ULTIMATE CAUSE: By chasing away other male sticklebacks, a male decreasesthe chance that eggs laid in his nesting territory will be fertilized by another male.

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 stimulusthat releases aggression in a male stickleback.

Nikolaas Tinbergen

• Studied courtship behavior of the stickleback fish.

• Identified a stimulus/response chain in animals.

• Saw sign stimuli as social releasers.

Social Releasers• Are sign stimuli one organism provides to

another to communicate:readiness to mate,location of food,potential danger

• Communicate through visual, acoustic, chemical, tactile, or electrical pathways.

• 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

Figure 51.9a, b

(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.

Auditory Communication• Experiments with various insects

– Have shown that courtship songs are under genetic control 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.

EXPERIMENT

SONOGRAMS Chrysoperla plorabunda parent

Vibration volleys

Standard repeating unit

Chrysoperla johnsoni parent Volley period

crossed with

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.

Volley period

The F1 hybrid offspring sing a song in which the length of the standard repeating unit is similar to that sung by the Chrysoperla plorabunda parent, but the volley period, that is, the interval between vibration volleys, is more similar to that of the Chrysoperla johnsoni parent.

RESULTS

The results of this experiment indicate that the songs sung by Chrysoperla plorabunda and Chrysoperla johnsoni are under genetic control.

CONCLUSION

Standard repeating unit

Volley

period

F1 hybrids, typical

phenotype

Social Environment and Aggressive Behavior

• Cross-fostering studies in California mice and white-footed mice

– Have uncovered an influence of social environment on the aggressive and parental behaviors of these mice

Influence of cross-fostering on male mice

Table 51.1

Variation in Aggressive Behavior• Funnel spiders living in different habitats

– Exhibit differing degrees of aggressiveness in defense and foraging behavior

Figure 51.19

50

40

30

20

10

0

Tim

e to

atta

ck (

seco

nds)

Field Lab-raised generation 1

Lab-raised generation 2

Desert grassland population

Riparian population

60

Population

Such competition may involve agonistic behavior:– An often ritualized contest that determines which

competitor gains access to a resource.Male competition for mates:

– Is a source of intrasexual selection that can reduce variation among males.

Figure 51.30

Betta splendens

A Real Life Example of Agonistic Behavior!

Discovery: Anatomy of a Shark Bite video

Communication Without Sound!

Elephant Biology

Elephant Communication

• The work of Dr. Katherine Payne

• The video, 48 Hours: Something Wild, July 2001

Orientation Behaviors• Orient by tracking stimuli in environment.

• Movement toward or away from stimulus- taxis. Ex. + phototaxis= insects to light.

• Other movements do not involve specific orientation. Only become more active under unfavorable conditions, inactive under favorable conditions.

• If activity is dependent on stimulus intensity- Kineses.

• Sow bugs:

– Become more active in dry areas and less active in humid areas

Figure 51.7a

Dry open area

Moist site under leaf

(a) Kinesis increases the chance that a sow bug will encounter and stay in a moist environment.

• Many stream fish exhibit positive rheotaxis

– Where they automatically swim in an upstream direction

Figure 51.7b

Direction

of river

current

(b) Positive rheotaxis keeps trout facing into the current, the direction from which most food

comes.

Konrad Lorenz• Studied

imprinting -forming social attachments early in life.

• Worked with goslings and filial imprinting.

• Imprinting seen as innate.

Figure 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.

• Conservation biologists have taken advantage of imprinting

– In programs to save the whooping crane from extinction

Figure 51.6