Transcript Chapter 51 Behavioral Ecology

Behavioral Ecology
Chapter 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 successUltimate 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 Mechanismsensory 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.
Learning
2. 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
Before stimulus
Influx of alarm substances
Influx of water alone
Influx of pike odor
Day 1
Relative activity level
Day 3
Figure 51.15
Control group
Experimental
group
Control group
Experimental
group
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.
EXPERIMENT
• In a classic
experiment, Niko
Tinbergen
– Showed how
digger
wasps use
landmarks
to find the
entrances
to their nests
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.
Nest
After the mother visited the nest and flew away, Tinbergen
When
returned,
shefeet
flewtotoone
theside
center
of nest.
movedthe
thewasp
pinecones
a few
of the
the pinecone circle instead of to the nearby nest. Repeating the
experiment with many wasps, Tinbergen obtained the same results.
RESULTS
No Nest
Nest
CONCLUSION
Figure 51.14
The experiment supported the hypothesis
that digger wasps use landmarks to keep track of their nests.
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
(a) A male three-spined stickleback fish shows its red underside.
Figure 51.3a
(b) The realistic model at the top, without a red underside, produces no aggressive
response in a male three-spined stickleback fish. The
other models, with red undersides, produce strong responses.
Figure 51.3b
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.
Figure 51.4
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.
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
(a) Minnows are widely dispersed in an
aquarium
before an alarm substance is
introduced.
Figure 51.9a, b
(b) Within seconds of the alarm substance
being introduced, minnows aggregate near
the
bottom of the aquarium and reduce their
movement.
Auditory Communication
• Experiments with various insects
– Have shown that courtship songs are under genetic control
EXPERIMENT 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.
SONOGRAMS
Chrysoperla plorabunda parent
Volley period
Vibration
volleys
Standard
repeating
unit
crossed with
Chrysoperla johnsoni parent
Volley period
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.
RESULTS
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.
F1 hybrids,
typical
phenotype
Volle
y
perio
d
Standard
repeating
unit
The results of this experiment indicate that the songs sung
by Chrysoperla plorabunda and Chrysoperla johnsoni are under genetic
control.
CONCLUSION
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
Desert
grassland
population
60
50
Time to attack (seconds)
Riparian
population
40
30
20
10
0
Field
Figure 51.19
Population
Lab-raised
generation 1
Lab-raised
generation 2
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 stimulustaxis. 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 intensityKineses.
• Sow bugs:
– Become more active in dry areas
and less active in humid areas
Moist site
under leaf
Dry open
area
(a) Kinesis increases the chance that a sow bug will
encounter and stay in a moist environment.
Figure 51.7a
• Many stream fish exhibit positive rheotaxis
– Where they automatically swim in an
upstream direction
Direction
of river
current
(b) Positive rheotaxis keeps trout
into the
Figurefacing
51.7b
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.
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 51.5
• Conservation biologists have taken
advantage of imprinting
– In programs to save the whooping crane
from extinction
Figure 51.6