Transcript Ecology

Ecology
The study of interactions
Ecology
Ecology:
the study of interactions
between organisms and their
environment.
Some examples:
1. How the brightness of rose color
affect the number of pollinators
who visit the flower.
2. How atmospheric pressure
affects the growth rate of
chickweed.
3. The change in population size of
aphids in an area where
ladybugs have been introduced.
Biotic Factor: the living part of the
environment
Abiotic Factor: the non-living parts of
the environment
Look at the
picture and
name the
biotic
factors.
Now name
the abiotic
factors
Levels of Organization in the Environment
The lowest level in the organization is the organism.
Organism: any living thing.
Examples:
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Fungus
Dragonfly
Dandelion
Bacteria
Prairie
Dog
– Toad
Population – organisms living together
and interbreeding
A population of prairie dogs
Community – collection of populations
that interact.
It
Ecosystem- all the biotic and abiotic factors in an area
Prairie (grassland) ecosystem:
• dominated by grasses and other non-woody plants called forbs.
• Result from interactions between precipitation, temperature,
landforms, soil drainage, fire, plants, and animals
Biosphere – all ecosystems on the planet.
Habitat:
where an organism lives
What is the habitat for:
–A bird?
–A polar bear?
–A salamander?
–A raccoon?
Niche: how an organism affects
and uses its environment
• What is the
niche for an
earthworm?
• Eats organic matter in soil
• Fertilizes soil as it burrows and defecates
• Is eaten by centipedes, birds, reptiles,
amphibians, and small mammals
What is the niche for:
–A bird?
–An earthworm?
–A polar bear?
–A salamander?
–A raccoon?
What did the gangsta ecosystem
say to it’s components?
What up my niches!!
Adaptation: any characteristic which helps
an organism survive in its environment.
Four adaptations of a bat:
• Wings
• Fur
• Nursery colonies
• Echolocation
You are What You Eat
Autotroph/producer:
An organism that makes its own
food.
Plants and some other
organisms make food
from sunlight energy
(photosynthesis)
Heterotrophs/consumers:
Organisms that get energy directly or
indirectly from plants
Types of heterotrophs:
1. Herbivore:
organisms
which feed only
on autotrophs
(plants).
Examples: deer,
rabbits, horses
2. Carnivores
Organisms
which feed
only on other
heterotrophs
(animals).
Examples:
wolves,
hawks,
anteaters
3. Omnivores
Organisms which
feed on both plants
and animals
Examples: humans,
bears, robins,
raccoons
Black rats are omnivores. They will eat grain,
fruit, corn, insects and eggs.
4. Decomposers
Animals which feed on decaying organic matter
(rotting plants and animals). Examples:
earthworms, fungus, some bacteria
Mushrooms (right)
and earthworms
are decomposers
5. Scavengers
Animals which
feed on other
animals which
are already
dead
(scavengers
don’t kill their
own prey).
Examples:
hyena, crows,
vultures, ants.
Energy Flow
through
the Ecosystem
Energy moves from the sun to plants
to primary consumers (herbivores) to
higher consumers (omnivores &
carnivores).
• A food chain shows the movement
of energy through a system.
Examples of food chains
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Leaf
caterpillar
robin
mosquito
Clover
deer
wolf
Minnow
salmon
bear
Grass
cow
human
Fly
frog
snake
alligator
Trophic Levels
Each link in a food chain is a trophic
level.
–Autotroph (beginning of the chain) first trophic level.
–Herbivore (eats the autotroph) second trophic level.
–Carnivore (eats the herbivore) third trophic level.
How many trophic levels?
Rotting fruit
Fly
frog
snake
Which organism is at the second trophic level?
Name the carnivores:
What kind of organism is a fly?
At which trophic level is the snake?
Can anyone in this chain be an omnivore?
Who is the highest order consumer in this chain?
How many trophic levels?
Clover
deer
wolf
How many carnivores?
How many autotrophs?
Which is at the third trophic level?
At which trophic level is the herbivore?
Name the next link in the chain if the
wolf dies and decomposes.
Food Web
A food web shows all the different food chains
in an ecosystem.
How many different food chains are in this web?
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How many food chains is the mosquito in?
What is getting energy from the worm?
How many autotrophs are in this web?
Is the energy flowing from the alder to the deer, or
from the deer to the alder?
What kind of ecosystem would have a food web like this one?
Which predators have the most sources of food in this web?
What is at the beginning of each food chain in this web?
Is the Herring a herbivore, an omnivore or a carnivore?
How many food chains do you see here?
What would happen if the snails were eliminated from this web?
Energy Pyramid:
Shows the movement of energy through
an ecosystem
• Bottom of the pyramid: 1st trophic level:
Autotrophs/producers: the most energy is here.
• Second trophic level: herbivores (first order
consumers) are here. Some energy is lost.
• Third trophic level: omnivores, small carnivores.
More energy is lost.
• Fourth trophic level: top carnivores and
omnivores. The least amount of energy is here.
Source of energy for the energy pyramid is The
Sun!
Energy is lost as it moves up the pyramid.
The pyramid is like climbing steps: Energy is
lost as you move up the stairs
You have the most energy at the bottom
You have the least energy at the top
Because less energy is available to for the consumers
at the top, there are less carnivores than plants.
Pyramid Practice
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Place the following species and terms in the correct location on the
ecological pyramid: (This will be turned in)
Rabbit
• Carnivore
Carrot plant
• Herbivore
Eagle
• Producer
Bear
• Secondary Consumer
Oats
• Primary Consumer
Deer
• Tertiary Consumer
Coyote
• 2nd Trophic Level
Snake
• 3rd Trophic Level
Omnivore
• 1st Trophic Level
Autotroph
• 4th Trophic Level
Least Energy • Most energy
Use the following organisms to create a food web:
rat, fox, human, cow, snake, corn, rabbit, hawk,
grass
Use a colored pencil or marker to identify one food
chain in your web
Create a menu for the organisms in this web that lists
2+ foods (appetizers, entrees, drinks, deserts) for
each organism in your web. Each menu item
should list the type of diet and the tropic level that it
is intended to feed. Ex:
– Fish stew with carrots and potatoes (feeds the
omnivore at TL3)
– Sunlight chips and dip (feeds the producer at
TL1)
Survival
What helps species to survive?
• Relationships with other species
• Adaptations to that environment
• Behaviors
Relationships Which Help
Survival
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•
Sometimes relationships between
species help the survival of one or both
species involved.
Examples of relationships:
1. Predator-prey relationships
2. Symbiotic relationships
• Mutualism
• Parasitism
• Commensalism
Predator-Prey Relationships
Example: cheetah (predator) &
gazelle (prey)
• Predator eats
prey.
• Both species
benefit.
• The predator
gets energy
from the prey
• The prey
populations
are controlled
by the
predator.
Sybiotic Relationships
•
Symbiotic relationships: close
permanent associations between
species.
• Three kinds:
1. Mutualism: Both species benefit
2. Parasitism: One species benefits, the
other is harmed
3. Commensalism: One species benefits,
the other isn’t helped or harmed.
Mutualism
Both species will
benefit from the
relationship
• The acacia tree and the
ant
– The ant defends the
tree against
predators and clears
out competition
– The tree provides
home and nectar to
the ant
Mutualism
• Gardenia thunbergia, a south African shrub,
has fruits which never fall from the tree.
• They are eaten by antelope and then the seeds
are dispersed in the antelope dung.
• Both the antelope and the shrub benefit.
Gardenia thunbergia also has a
mutualist relationship with the hawk
moth, who moves from plant to plant,
lapping nectar and pollinating the plant
with its long tongue.
Parasitism
One species benefits (the parasite) and the other
is harmed (the host).
• Parasitism is
common in
flowering plants.
• Mistletoe is a
parasite.
• This dwarf
mistletoe is
growing on a
Jeffery Pine.
Parasitism
Dodder, a relative of
mistletoe, steals
moisture and nutrients
from laurel sumac in
California.
• Cowbirds are nesting parasites
• They lay eggs in the nests of other birds.
• The larger cowbird babies outcompete the other nestlings for food, often
causing the host babies to die.
(Above) A huge cowbird chick shares the nest with a smaller sparrow chick.
(Top right) A Vireo feeds her baby and a cowbird nestling. (Bottom right)
Cowbird eggs in a thrush nest.
Commensalism
One species benefits, the
other isn’t affected at all.
The clownfish is protected from predators by the stinging
tentacles of the anenome. It secretes a mucus which keeps it
from being harmed by the poison itself. The anenome isn’t
affected one way or another by the clownfish.
Commensalism
• Barnacles are crustaceans which attach to a
stationary surface to live and feed.
• Barnacles often attach to mollusks.
• The barnacle gains a stable foothold, and the
mollusk isn’t affected.
Commensalism
• The cattle egret perches on grazers, eating the
insects disturbed during the grazing process.
• The larger animal isn’t affected, but the egret
benefits from an increased food supply.
Match:
(a) predator-prey (b) mutualism
(c) Parasitism (d) commensalism (e) adaptation
__ A student selects the same food as the student
in front of them because the first student knows
what is good to eat.
__ A large brain allows students to learn biology
__ One student cheats off of another student
__ One student steals from another student
__ Two students study together and help each
other with difficult concepts
__ A car drafts off of a truck on the interstate
__ Students go fishing and have a fish fry
Characteristics Which Help Survival
• Adaptation: Characteristics that species
develop over time which help them to
survive in their environment.
• Important adaptations: opposable thumb,
prehensile tail, jointed appendages, four
chambered heart…
• Special types of adaptation:
– Camouflage
– Mimicry
Adaptations
Opposable thumb: thumb that
allows grasping and holding
Adaptations
Prehensile tail: tail that
can function as a fifth
limb and allows
animals to hang from
branches
Adaptations
Jointed appendages:
• Arms and legs which
can bend
• Function in walking,
feeding, fighting and
mating.
• First developed in
arthropods.
Adaptations
Four chambered
heart:
• Separates
oxygenated and
deoxygenated
blood
• Allows more
oxygen to reach
tissues.
Camouflage
• Any body
structure or color
which allows an
animal to blend
with its
environment.
• Camouflage helps
animals hide from
both predator and
prey.
A canyon frog
camouflaged against a
canyon wall
Camouflage
A rock ptarmigan camouflaged
against the landscape
A desert horned lizard in a
sandy riverbed.
Walking stick
Praying mantis
(R) Katydids;
(below R) Geometrid
moth;
(below) Red
Diamondback
Rattlesnake
(R) Crab spider;
(Below R) Pipefish
in eelgrass;
(Below) Ambush
Bug
Camouflage
Top left: Flatfish; Above left: Stone fish; Above right: Leafy Seadragon.
Mimicry
An animal mimics (copies) the appearance or behavior of a
more dangerous or toxic species. Predators are fooled, and
avoid both the venemous species and the mimic.
A bluejay eats a monarch butterfly and then vomits.
The monarch is toxic to the bluejay. The bluejay will
avoid eating the monarch now.
Monarch or Viceroy?
In addition to avoiding the monarch, the blue jay will
avoid eating the viceroy because it resembles the
monarch. The jay can’t tell the difference.
Behavior
Behaviors Which
Do Not
Help Survival
Behaviors Which Help
Survival
Two kinds of behaviors:
– Innate Behavior: instinctive behavior animals
are born with
– Learned Behavior: behaviors animals develop
after birth through experience
Innate Behavior
1. Fight-or-flight: when confronted by danger,
your heart speeds up, skin becomes
sweaty and breath rate increases.
2. Territorial Behavior: Animals become
aggressive defending their nest/territory.
3. Courtship/mating behavior: rituals in
attracting a mate
4. Reflex: responses to environmental cues
5. Instinct: natural behaviors for particular
situations (mothering, nursing)
FightorFlight
Territorial
Behavior
• Dogs/wolves mark
trees with urine
• Three-spined
stickleback fish flash
their red belly to other
male fish. The other
males respond by
attacking or leaving.
Courtship/mating
• Male turkeys & peacocks
spread a plume for
females
• The male spider captures
a bug and wraps it into a
silk web to present to the
female as a gift
Reflex
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Knee-jerk reflex
Pulling your hand
away from a hot
object
Gag reflex
Frogs have insect
detector cells in the
retina of their eyes.
When fly moves
across their line of
vision, their tongue
jumps out and
catches the insect.
This end stinks?
Instincts
No!
Instincts
Instinct
• Grey-lag goose hens roll eggs back to the nest if
they roll out
• Rabbits pull hair to line the nest before having a
litter of babies.
• Robins eat
worms and
then
regurgitate
into their
offspring’s
mouths to
feed them.
Learned Behaviors
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Habituation – getting used to a stimulus
Conditioned response: learning by
association.
Imprinting: animals, at a certain critical
time in their life, forms a social
attachment with another object/animal
Learning by trial and error
Habituation
• Horses exposed to
frequent loud
sounds will stop
jumping
• You hearing a clock
ticking after being in
the room for a few
minutes.
• People who live in the city eventually stop noticing
the sounds of traffic
Conditioned Response
• When the bell rings,
students run from
the room.
• When your dog
hears you open the
refrigerator, he
comes to beg for
scraps.
Imprinting
• Voice imprinting of a
mother bat and her pup
among millions of bat
pups in a nursery colony
• Imprinting of stripe
patterns between zebra
babies and moms
• Ducks imprint and follow
the first conspicuous
object they see after birth
Trial-and-Error
• Trial-and-error
helps Jackdaw
birds to build
better and better
nests
• Riding a bike
• Mice learn to get more food by chewing
through sacks of grain in a barn.
Quiz
• Get your clicker
• Turn it on
• Get ready to respond!
Quiz
Match: a) habituation b) trial-and-error
c) Conditioned response d) imprinting
1.__ getting up when the alarm rings
2.__ a baby calf recognizing his mother’s moo
3.__ a hunting dog not being frightened by the firing
of a gun after constant exposure
4.__ a monkey learns how to get ants by putting a
stick inside an ant mound
5.__ not noticing a bracelet after wearing it all day
6.__ heron get better at fishing with experience
Quiz
(A) Innate
(B) Learned
7.__ Cats arch their back and hiss when confronted by
a dog
8.__ getting up when the alarm rings
9.__ Alligators dig a hole to lay their eggs in, and then
cover up the eggs with sand
10.__ a monkey learns how to get ants by putting a stick
inside an ant mound
11.__ not noticing a bracelet after wearing it all day
12.__ Your eyes will blink when something moves
quickly towards them
13.__ Cats rub against objects and people to place their
scent on things in their surroundings
Quiz
Match: a) fight-or-flight b) Territorial behavior c) Courtship
behavior d) Instinct e) Reflex
14.__ A female rabbit tries to bite when people put their hand in
the rabbit’s cage
15.__ Cats arch their back and hiss when confronted by a dog
16.__ Alligators dig a hole to lay their eggs in, and then cover up
the eggs with sand
17.__ Your eyes will blink when something moves quickly towards
them
18.__ Male frogs give a particular call when trying to find a mate
19.__ Your arms will cover your face when something is thrown at
your head
20.__ Cats rub against objects and people to place their scent on
things in their surroundings
Quiz
(A) Innate
(B) Learned
21.__ A female rabbit tries to bite when people
put their hand in the cage during nesting
22.__ a baby calf recognizing his mother’s moo
23.__ Male frogs give a particular call when
trying to find a mate
24.__ Your arms will cover your face when
something is thrown at your head
25.__ a hunting dog not being frightened by the
firing of a gun after constant exposure
26.__ heron get better at fishing with experience
a. Habituation
b. Imprinting
c. Instinct
d. Reflex
e. Trial and Error
f. Conditioned
Response
g. Innate behavior
27.__Any behavior which an animal is
born with
28. __Screaming when frightened
29.__Getting out of bed when the
alarm rings
30.__Getting used to glasses on the
nose so you don’t notice them
31.__Jerking a hand off a hot stove
32.__Getting better at algebra after doing practice
problems
33.__An opossum plays dead when threatened by a
predator
34.__Baby giraffes recognize mom by spot patterns
35.__A teenager gets better at driving a car while driving
on learner’s permit
Populations
Population Growth Patterns*
• Environmental conditions control
population growth.
• Lots of food, few predators,
disease = rapid population growth.
• Poor environment (pollution,
draught, habitat loss…) = negative
or slow population growth.
Graphs show how populations change or maintain their size.
J-shaped curve:
• S-shaped curve: initial
rapid population
growth, and then a
growth due to
leveling out of population
unlimited resources
growth when there are
just enough resources to
maintain the population.
S-shaped Curve
1.
Growth of a yeast population in culture: after a period
of exponential growth, the size of the population
begins to level off and soon reaches a stable value.
J-Shaped Curve
1. Human
population
growth from
10,000 B.C.
until the
present day
Other Kind of Curves
When two species are cultured together, the less successful
species will decline. The more successful species
population will increase until the food source runs out,
then it will also decline.
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Lemmings = small Arctic rodents
population explosions every 3 to 5 years.
When population peak, lemmings migrate.
When they come to a stream they jump in and swim across.
Unfortunately, when they reach the ocean, they do the same
and die in the sea.
• Two frog populations on St. George’s island.
• One was barely successful due to limited
food supply
• The other was very successful for about 20
years until a parasite wiped its food source
•
Snowshoe Hare and Canadian Lynx are dependent upon each other.
The population of the hare is almost always greater than the
population of the lynx. When hare populations are successful, the lynx
population grows in response due to abundant food. As lynx
populations grow, hare populations suffer, causing lynx populations to
suffer also.
Things affecting population size:
Limiting factor: anything which prevents
rapid population growth. Two kinds:
– Density dependent factors: biotic things
affect population size. Examples: disease,
famine, competition for resources and
nesting sites
– Density independent factors: abiotic
things which affect population size.
Examples: earthquake, flooding, fire
Carrying capacity
Carrying
capacity is
when the
environment
has just enough
resources to
maintain the
current
population size.
In this graph of
yeast grown in a
culture, the
culture was
exposed to heat
and all the yeast
died. Was the
limiting factor
density
dependent or
density
independent?
In this graph, a population of osprey grew
until they ran out of nesting sites. The
population leveled out at that time.
1. What was the limiting
factor?
2. Was it density
dependent or
independent?
3. Which part of the
graph shows where
the population
reached carrying
capacity?
This graph
shows a
population of
field mice.
1.
2.
3.
What happened to the population near the end of the
graph?
Name three possible density dependent limiting factors
which may have caused this decline (other than what
was named in the notes).
Name three density independent factors which may have
caused this decline (not the ones listed in the notes)
Comparing J-curves and S-curves
1. Which of the graphs shows that there were
limiting factors?
2. Which of the graphs shows carrying capacity?
3. Does the s-shaped graph show limiting factors?
4. What do you think will happen to the J-shaped
curve, given enough time?
Test Practice
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