Download ANIMAL BEHAVIOR Ch 51 Animal behavior involves the actions of

ANIMAL BEHAVIOR
Ch 51
Animal behavior involves the actions of
muscles and glands, which are under the
control of the nervous system, to help an
animal respond to a stimulus
I. KINDS OF ANIMAL BEHAVIOR
A. Innate Behavior = developmentally
fixed behavior
1. Fixed action patterns
 A sequence of unlearned acts
that is unchangeable and is
usually carried out to
completion
 Example: male stickleback
fish (they have read bellies)
will attack other males that
invade their nesting territories
but won’t attack females (no
red bellies
 What is the stimulus?
 How could they prove this?
2. Oriented movement
 Kinesis: undirected movement
of an animal in response to
environmental condition.
Pillbugs are more active in dry
conditions than in moist
conditions. Why? Clue:
Pillbugs breathe thru gills. All
respiratory membranes must
be moist for gas exchange
 Taxis: directed movement
towards or away from a
stimulus. Ex: trout orient
themselves upstream. Why?
 Migration: seasonal movement
of animals for long distance
o Is circannual and usually
follow sun’s position in sky to
help them navigate
o What might be the
stimulus to initiate migration?
3. Imprinting
 Behavior is acquired ONLY if
appropriate stimulus is
provided during the
CRITICAL PERIOD
 Once behavior is acquired it is
irreversible
 In birds, young imprint on
parent and learn basic
behaviors of their species.
 If critical period passes
without imprinting, then
species-specific behavior is not
learned
4. Behavioral rhythms
 Behavior that follows a biological
clock
 Circadian rhythms follow a daily
clock like nocturnal vs diurnal
animals
 Circannual rythms follow a
yearly clock like mating and
migration
o Most follow changes in
light/dark during the year to cue
them
5. Animal communication:
transmission of a signal from one
animal induces a behavior in another
 Chemical signal secreted by one
animal like marking territory
o Can involve pheromones that
are secreted by females to
indicate readiness to mate
 Visual
o To show courtship or
aggression: baring teeth and
courtship dances
 Auditory
 Tactile = touch
o Greeting, grooming. Mating
B. Associative Learning = Learned thru
interactions with environment
 Classical conditioning = animal
responds to substitute stimulus
 Operant conditioning = animal learns
behavior thru positive or negative
stimulus
 Habituation = animal learns to ignore
meaningless stimulus
 Observational learning = animal
learns by observing other animals
 Insight = animal performs a behavior
without being learned
II. Genetics Of Behavior
A. Is behavior the result of genetics or is
it learned?
Genes provide the instructions for
behavior
Nongenetic factors will modify how
instructions are carried out
Some behavior is more genetic than
learned and visa versa.
o More genetic? In what type of
animal?
o More learned? In what type of
animal?
o Physiological factor involved?
B. Is variation in a particular behavior
evidence for evolution?
Case study: variation in migratory
patterns
C. The purpose of behavior is to enhance
survival
What is natural selection?
Genes for behavior have evolved by
natural selection in order to enhance
survival
o Foraging behavior
o Mating behavior
POPULATION ECOLOGY
CH 53
TERMS:
Population: members of the same species
living together
Community: a bunch of populations
living together
Ecosystem: all of the biotic and abiotic
factors in a region
Biosphere: part of the Earth that has
living things
Habitat: place where an organism lives
Niche: living and nonliving resources of
an organism
I. POPULATION ECOLOGY
Study of the growth, abundance and
distribution of populations
A. POPULATION ABUNDANCE AND
DISTRIBUTION
1. Population size:
N
 Total number of individuals in the
population
2. Population Density:
 Number of individuals per unit area
3. Age structure
 The abundance of individuals of each
age
o Pyramid shaped curves indicate a
rapidly growing population
o Rectangular shaped curves indicate
a stable population
4. Survivorship curves
 Describes the mortality of individuals
during their lifetime
o Type I species: most survive to
middle age or older
example humans
tend to be large mammals that
produce few offspring but provide a
lot of care
o Type II species: length of survival
is random. Equal likelihood of
death at any age
example rodents
o Type III species: most of the
individuals die young
Tend to be organisms that produce
a lot of offspring with very little
care
example oysters
B. POPULATION GROWTH
1. exponential growth
 The maximum growth rate of a
species under IDEAL conditions
 The equation for exponential growth
is:
dN/dT = rmaxN
 Factors that affect the rmax of a species
o Age at which they reproduce
o Average # offspring produced in
each breed
o How frequently they reproduce
o How long they can reproduce
o How many offspring survive to
reproduce
2. Logistic Growth
 As the population reaches the
carrying capacity of the environment,
growth decreases and approaches zero
 Represented by the following formula:
dN/dT = rmaxN(K-N)
N
K = carrying capacity N= #individuals
K-N = #of new individuals the
environment can support
K-N/N = fraction of K that is still
available for population growth
 The smaller N is the closer K-N/K is to
1 and the growth rate approaches the
maximum rate
 The larger N is the closer K-N/K is to
zero and the closer the growth rate
approaches zero
 What happens if N>K?
3. Carrying capacity: the maximum
number of individuals of a population
that the environment can support
 Factors that limit the carrying capacity
and biotic potential of a population
o Parasites and disease
o Resources
o Toxic effects of waste
o Stress of too many individuals inhibits
reproduction
o predators
These are density dependent. What does
that mean?
Examine the graph:
a. explain the change in population size
from 1955 to 1956 and from 1956 to 1958
in terms of competition for resources
Examine the following graph:
a. which is the predator and which is the
prey?
b. explain the graph
C. REPRODUCTIVE PATTERNS ARE
THE RESULT OF NATURAL
SELECTION
 Any trait that would enhance an
organism’s chances to survive and
reproduce is favorable
 However, there are tradeoffs between
survival and reproduction
o The greater the chance of survival,
the more energy can be invested in
reproduction
 Species whose young have a high
rate of survival like primates
tend to produce few larger young
and invest energy in their care
o The lower the chance of survival the
less energy will be invested in
reproduction
 Species whose young have a
lower chance of survival, like
insects, produce a lot of smaller
young and don’t invest energy in
their care
2. reproductive strategies can be kselected or r-selected
 K-selected strategies
o Tends to operate in a stable
environment and is under the
influence of density dependent
factors
o Organisms that are extreme kstrategists tend to have the
following reproductive
characteristics:
 Fewer larger offspring
 Lots of parental care
 Slower maturity
 Often reproduce more than once
 Most offspring survive to
reproduce
 Because most offspring survive
they can invest a lot of energy in
their young
 R-selected strategies
Tend to operate in an unstable
environment and subject to density
independent factors
o Characteristics of r-strategists:
 many small offspring
 little or no parental care
 early reproductive age
 often reproduce only once
 most offspring die before they
reproduce
 because survival of offspring is
low they tend to invest little
energy in their young
COMMUNITY ECOLOGY
CH 54
A. Interactions Between Populations
1. Interspecies competition: two different
species compete for the same resource.
This often results in one species
succeeding over the other
2. Resource partitioning occurs when
species coexist despite their competition
for the same resources because they live
in slightly different niches
3. predation occurs when one species
negatively uses another species for food.
Is a cow considered a predator?
4. Symbiosis occurs when two species live
in close contact
 Mutualism: both species benefit
 Commensalism: one species benefits
 Parasitism: one species benefits and
the other is harmed
B. EVOLUTIONARY ADAPTATIONS
THAT HELP PREY AVOID
PREDATORS AND HELP
PREDATORS CATCH PREY
In order for a predator-prey relationship
to continue they both must be able to
successfully reproduce
1. Evolutionary adaptations that help
prey avoid predator
 Chemical produced by certain plants
that discourage herbivore from eating
them
 Camouflage or cryptic coloration is
the color, pattern shape, or behavior
that allows an animal to blend into its
surroundings
 Aposematic or warning colorations
the coloration or pattern of an animal
that warns predators that they should
be avoided
Poison dart frog
 mimicry occurs when two species
resemble each other
a. mullarian: animals with the same
mechanism of defense share the same
coloration
(a) Cuckoo bee
Two unpalatable species mimic each (b) Yellow jacket
other
.
b. batesian: one animal with no defenses
resembles another animal with defenses
(b) Green
parrot snake
Hawkmoth larva
A harmless species mimics
a harmful one.
2. Evolutionary adaptations that allow
predator to capture prey
 acute sense of smell
 speed
 claws, fangs, stingers, poisons
C. Effect of Dominant, Keystone, and
Introduced Species on Community
Structure
 species diversity: the variety of
different species on a community. Has
2 components:
o species richness: the number of
different species in the community
o relative abundance: the amount of
each species in the community
1. Dominant species
 most abundant species in the
community
 it controls the distribution of other
species
 ex: sugar maple is abundant species in
northeast forests and provides shade
and good quality soil
what might happen if the dominant
species declined in number?
How did it become a dominant species?
2. Invasive species
Organisms that are introduced to a new
community, usually by humans
Why are they so successful?
Ex:
3. Keystone species
Affects community structure not by
being abundant but by its role in the
community
Ex: sea otters
Kelp→ sea urchin→ sea otter
How does the sea otter population affect
the kelp abundance?
ECOSYSTEMS AND ENERGY FLOW
CH 55
A. THE CYCLES
1. Water cycle
a. The water from oceans evaporates into
the atmosphere
b. Water from plants evaporates to the
atmosphere by transpiration
c. Water precipitates from the
atmosphere to the earth
d. Most of the water enters into the
oceans
e. Some of the water is taken up by living
organisms
2. The Carbon cycle
a. CO2 in the atmosphere is fixed by
photosynthetic organisms
b. animals eat the photosynthetic
organisms
c. animals respire and put CO2 back into
the atmosphere
d. animals die and their remains become
fossil fuels
e. fossil fuels are burned and CO2 is
deposited in the atmosphere
3. The nitrogen cycle
a. atmospheric N2 is fixed by nitrogen
fixing bacteria and used by plants
b. herbivores eat the plants
c. herbivores pee, poop and die returning
nitrogen to the soil which is then fixed by
nitrogen fixing bacteria in plants
d. Carnivores eat herbivores
e. Carnivores pee, poop, and die
returning nitrogen to the soil to be fixed
f. some bacteria in the soil take the soil
nitrogen and restore it to atmospheric
nitrogen
B. TROPHIC LEVELS
1. Primary Producers
a. Autotrophs that produce glucose
2. Primary consumers
a. Herbivores that eat primary
producers
3. Secondary consumers
a. carnivores that eat herbivores
4. Tertiary consumers
a. Eat secondary consumers
5. Detrivores
a. consumers that eat dead stuff
C. ECOLOGICAL PYRAMIDS
 Show the relationship between trophic
levels
 Why is energy flow thru ecosystems
inefficient?
o 10% rule: 10 % of energy from 1
trophic level is available to the next
o Rest of the energy is used by the
organism or lost as heat or waste
o Therefore:
There are a limited # of trophic
levels
There are fewer and fewer
organisms/mass/energy in higher
trophic levels
This creates pyramid of
numbers/biomass/energy
D. ENERGY FLOWS THROUGH
ECOSYSTEMS
 Primary productivity
o .the amount of organic material
produced by autotrophs in a given
period
 Gross primary productivity
o the amount of organic material
produced
o net primary productivity
the amount of organic material
that is available to heterotrophs
o Secondary productivity
The production of new biomass by
heterotrophs
 Productivity and photosynthesis
The more photosynthesis, the greater the
primary productivity and the greater the
production of new biomass
Therefore the ecological pyramid will be
broader
III. Ecological Succession and
Community Disturbances
A. Community Disturbances
A change in a community due to the
destruction of resources and death of
organisms
o Natural disturbances
Fire, hurricane, volcanos
o Human disturbances
Clearing of land, sinking of ships
Community disturbance could be
positive or negative
o Positive: sunken ship provides new
habitats for fish
o Negative: volcanic eruption destroys
communities
B. Ecological Succession: Colonization of
new species into the disturbed area
a. Primary succession:
when a force like a volcano destroys
everything in community even soil
moss and lichen grow on hardened lava
and make soil
small plants like grasses start growing in
soil from blown in seeds
shrubs and trees start to grow
b. Secondary succession
When a force like a tornado or an
abandoned farm destroys everything but
leaves soil intact
Grasses start to grow then shrubs and
trees
II. How Have Humans Affected Species
Diversity
A. Deforestation
 Clearing of land for farming or
housing
 Destroys animal habitats so they have
no place to live
 Many organisms die
B. Hunting
 Excessive hunting kills many animals
 By doing this species become
endangered
 They are forced to inbreed and this
makes them weakened
C. Introduced Species
 A nonnative species brought in by
humans
 Many thrive and take over a
community because they have no
known predators