Download CH 41 Animal Behavior Notes

(9/13) BR
1.
What are some things that affect or
cause animal behavior? Consider
both internal and external stimuli
that cause or change an animal’s
behavior.
2.
Could a behavior be an adaptation?
Why or why not?

4 Questions:
1. Causation: What is the immediate stimulus for the
behavior?
2. Development: How does behavior change with age
and learning—what experiences are necessary for it
to be displayed?
3. Function: How does the behavior affect chances for
survival and reproduction?
4. Evolution: How does the behavior compare with
similar behaviors in related species, and how might
it have evolved?


Proximate causes—genetic, physiological, neurological,
and developmental mechanisms
 “How does a trait work?”
Ultimate causes—evolutionary processes that produced
the capacity and tendency to behave in certain ways
 “Why does a trait exist?” How does it increase an
organism’s chances to survive and reproduce?

Behaviorism—neural reflexes can be modified by
experience (learning)
Pavlov’s dogs: the
conditioned reflex

Ethology is the study of fixed
action patterns – genetically
determined instinctive
behaviors
 Triggered by releasers
(simple stimuli)
 Example: Gull chicks
respond to a red dot on
their parents’ bills to
initiate pecking behavior
to get food…what is the
releaser for this fixed action
pattern?
What can you conclude from this graph???
(correct head
shape)
*A red dot is
more important
than a realistic
profile
*Head color and shape
have little effect on the
ability of a red dot to
stimulate the begging
response

Some behaviors are genetically determined
 Ex: hygienic & nonhygienic behavior in honeybees
Hygienic bees uncap (u)
cells and remove (r) the
dead pupae
u is the “uncap” allele
r is the “remove” allele
u is the
“uncap”
allele
r is the
“remove”
allele
Uurr are nonhygienic, but
will remove dead pupae if
cells are uncapped
uuRr are nonhygienic. They
will uncap cells of dead pupae,
but won’t remove them


Mutants with altered behaviors allow studies to
identify the genes involved
 Ex: fru in fruit flies
Gene knockouts (animals engineered to lack a gene) can
reveal roles of specific genes
 Ex: olfactory reception in mice related to mating
behavior via pheromones (signaling molecules)
Examine the
results of this
gene knockout
experiment in
which males
were engineered
to lack the VNO
receptor. What is
the role of the
VNO pheromone
receptor in male
mice? Was the
hypothesis
correct?

Hormones can control development and expression of
behavior
 Ex: sexual behavior in rats
What is necessary for
estrogen (♀sex
steroid) to produce
FEMALE sexual
behavior in adults?
Estrogen exposure
later in development
& NO testosterone
early in development
In part (B) what is
always necessary for an
adult to exhibit MALE
sexual behavior?
Exposure to
testosterone as a
newborn
Conclusion: sex
steroids present at
birth determine pattern
of behavior; steroids
present as adults
determine when
behavior is expressed

Imprinting—animal learns a set of stimuli during a
critical period, or sensitive period
 Ex: Emperor penguin recognition of parents and
offspring.
(9/19) BR
1. When a new lion takes over a
pride he often will kill the
young cubs of his predecessor.
Describe:
a. a proximate cause
b. and an ultimate cause for this
behavior .
2. In silverback gorillas the males
will hoot and pound their chests
when other animals enter their
territory. Describe:
a. a proximate cause
b. and an ultimate cause for this
behavior .

Bird song males learn during a limited developmental
time frame
 When a bird is deafened before starting to sing, he cannot
match his song with his song memory
 When a bird is deafened after singing has begun, he will
continue singing like a normal bird
  Birds must make song memory (imprinting) AND
later be able to match singing to memory
 Birds will only learn the song of their species
(genetic/instinct)
 Hormones control timing and expression by altering
brain structure and function
Bird must first acquire
a song memory by
hearing the song as a
nestling AND must
then be able to hear
himself as he attempts
to match his singing to
that song memory.
Yellow = LIGHT, Black = DARK, Gray = ACTIVE
Mouse activity in 12
hours of light and
12 hours of dark 
Mouse activity in
constant dark 
3. Does the natural
circadian rhythm of
the mouse follow a
24-hour cycle? Use
the diagrams to
explain your
answer.
Yellow = LIGHT, Black = DARK, Gray = ACTIVE
Mouse activity
when exposed to 12
hours of light and
12 hours of dark
Mouse activity in
constant dark
shows a natural
cycle that is slightly
less than 24 hours
If a mouse is given
20 minutes of light
at the same time
every day, it
becomes entrained
(9/20) BR
1. We have discussed investigations that revealed the
proximate causes for several behaviors. Identify the
proximate cause for each behavior below:
a. Hygienic & nonhygienic behavior in bees
b. Distinguishing male vs. female during mating in
mice
c. Sexual behavior in rats
d. Imprinting (video)
e. Male white crown sparrows sing their speciesspecific song
f. Circadian rhythms in mice

Circadian rhythms are daily cycles of activities
dependent on both genetics (e.g., clock genes expressed
in the brain) and environmental conditions (e.g., hours
of light/dark)
In mammals, the
expression of
“clock genes”
within the
suprachiasmatic
nuclei of the brain
control circadian
rhythms.


Rhythm has to be entrained to light-dark cycle
Under constant conditions (e.g., constant dark), an
animal’s circadian clock will run according to its
genetically determined cycle

Navigation & movement
 Piloting - knowing and
remembering the structure
of the environment
 Homing- ability to return
to a specific location even
w/out visual cues
 Ex: pigeons
 Compass sense allows them
to use environmental cues
like the sun & stars
The gray-headed albatross may be able to detect latitude and longitude
in returning to its island of birth after being gone 8-9 years!!

Communication - behaviors can evolve into signaling
systems if both sender and receiver benefit
 Pheromones – chemical signals (odor)
 Species-specific because proper receptor is needed
for detection
 Visual, Acoustic, Mechanosensory (touch) signaling
may be utilized
 Ex of mechanosensory communication: waggle
dance in honeybees
 Courtship behaviors often involve a combination
of communication sensory signals
Waggle dance in
honeybees
(mechanosensory)
The angle of the waggle
dance in relation to the
sun tells other bees the
direction of the food
source, and the duration
of the dance indicates
how close it is.

(9/20) BR
2.
What are some costs that
an animal may have to
consider before engaging
in a behavior?
3.
Mating behaviors have
evolved that maximize the
fitness of the parents and
offspring. What does
fitness mean?
4.
What does it mean if
someone is altruistic?


Habitat must provide food, shelter, nest sites, escape
routes, etc.
 The cues animals use to select habitat increase
fitness: the ability to survive and reproduce
Cost–benefit approach assumes animals have limited
time and energy
a. Energy cost
b. Risk cost
c. Opportunity cost - benefit the animal forfeits by
not performing other behaviors


The Cost-benefit
approach is used to
study territorial
behavior, which:
 requires considerable
energy
 may make a male
more vulnerable to
predation
 reduce time for
feeding or parental
behavior
Ex: spiny lizards

In some species males gather in a lek—a communal
area to display prowess and impress females
 If the performance requires time and energy, why do the
males perform the behavior? What is the ultimate
cause?



Mating systems vary widely among species; ultimately,
the mating system of a species is the one that that
maximizes fitness
Monogamous—strong lifelong pair bonds; shared
parenting
Promiscuous—males mate with many females; females
raise young


Polygyny – male has more
than one mate—fitness is
increased by having more
females.
 Leads to sexual
dimorphism (males look
different from females)
 Ex: elephant seals
Polyandry – one female
mates with many males—
increased paternal care
improves fitness
 Ex: golden lion tamarin 



Altruism – behavior benefits another at a cost to the
performer
An animal’s offspring contribute to its individual
fitness
Inclusive fitness: individual reproductive success
plus that derived from relative’s success.
 Kin selection: selection for behaviors that increase
a relative’s success, at a cost to the performer
 Ex: scrub jays

Eusocial species include nonreproductive members
 Ex: Hymenoptera order (wasps, bees, ants)
 Haplodiploidy—females are diploid, males are
haploid; only the queen is fertile
 Ex: mole rats

Group living costs/benefits
 improves foraging efficiency
 reduces risk of members
becoming prey
 Alarm calling reduces
predation risk
 Ex: ground squirrels
 Costs:
 Less food/individual
 Increased risk of disease and
parasites
EXIT slip
When a male robin is in reproductive condition, it has
bright red breast feathers. It aggressively attacks other
male robins, but it will also attack a simple tuft of red
feathers on a stick.
1. What is/are the proximate cause(s) of the behavior?
2. What is/are the ultimate cause(s) of the behavior?
(9/21) BR: Explain the ultimate cause for altruistic behavior.
Use the term inclusive fitness in your explanation.
You have a quiz on CH 1 & 41 on FRIDAY. Take out your
notes for CH 1 & 41 and jot down any concepts you are
struggling to understand.
* You should ALWAYS do your study guides with your notes
and, if possible, textbook handy!
PILLBUGS!
• Next week you will be performing a lab in which you
investigate pillbug behavior in groups of 3 or 4. Figure out
your groups, then share your research information AND
citations. Add new information to your research page if you
hear/see any!
• In your groups discuss the proximate and ultimate causes of
the different behaviors you recorded
• Your experiment will attempt to determine if pillbugs prefer
one type of environment over another, so you will be
distinguishing two general types of orientation behavior:
• Kinesis – change in activity in response to a stimulus;
random movement
• Taxis – oriented movement toward (positive) or away
(negative) from a stimulus
• Ex: chemotaxis, phototaxis
Exit: Reflection
1. On your bellringer, reflect on your score on the quiz on
Wednesday. Did you do as well as you expected? If so,
which study strategies worked for you? If not, how do
you think you can better prepare yourself for future
quizzes and tests?
2. Create 2 rectangles on your bellringer, and label one
“Clear” and the other “Unclear.” In the “Clear” box,
write down the information from CH 42 that you feel you
understand. In the “Unclear” box, write down any
information or concepts about which you feel confused.