1. Community Interactions

2. Competition The two flowering plants are competing for the same space
Which
means both
of them are
harmed.

3. Competition
Competition is when two organisms use the same space and resources at the same time.
Competition can occur between organisms of the same species or different species
Competitive Exclusion Principle – No two species can occupy the same niche in the same habitat at the same time.

4. Kudzu Competition Kudzu was introduced to the
United States in 1876 at the
Centennial Exposition in
Philadelphia, PA.
It “outcompetes” other
native plants so they don’t
have a place to grow.
Very prevalent in NC
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5. Competition – introduced species
The Eastern Bluebird is being forced into smaller numbers by the House Sparrow, an introduced species.
Sparrows will kill bluebirds and young.

6. Mutualism – clownfish and anemone
The clownfish gets protection from the anemone and in
return protects the anemone from fish that would eat it
(angelfish); the clownfish also keeps the anemone free of
dirt and debris.

7. Mutualism
Mutualism is a relationship between two organisms where both of them benefit from the relationship.
This can involve providing food, protection, a place to live or even pollination.

8. Mutualism - Lichens Lichens consist of a fungus with an algae
or photosynthetic
bacterium living
inside the fungus.
The alga provides
food for both of them
and the fungus
provides a habitat for
the alga.
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9. Mutualism – cleaner shrimp
These shrimp set up
large cleaning stations
on the reef where fish
will come to have
parasites picked from
their skin. The shrimp
gets a constant food
source and the fish (eel
in this case) gets rid of
potentially dangerous
parasites

10. Cleaner Shrimp on a Grouper

11. Mutualism – Ant and Aphid

12. The Aphid and the Ant Aphids feed on the sap of the plant they are on.
Ants use their antennae to stimulate the aphids and cause them to excrete from their abdomen a substance called honeydew which is rich in the nutrients ants require.
Each worker ant goes from aphid to aphid collecting honeydew which she stores in her abdomen until it's full; then, she returns to the nest and regurgitates to feed other members of the colony.
Ants, in return for the honeydew, protect the aphids from predators such as flies, wasps, and beetles.
The ants, like human ranchers, sometimes move their aphids to richer grazing grounds.
YUMMY!

13. A Little Aphid Ant Humor

14. Mutualism – sea slug with algae
The algae
lives in the
sea slug
and makes
food for
both of
them – in
return it
gets a place
to live.

15. Nitrogen fixing nodules
Bacteria in the
nodules can take
nitrogen gas from
the atmosphere
and turn it into a
form that can be
used by the plant;
in return, the plant
protects the
bacteria from
harmful oxygen and
the bacteria get
food from the plant.

16. Mutualism - pollination
Many plants depend on
pollinators for their
reproduction. They
provide nectar to attract
these pollinators. So
the pollinator gets fed
and the plant gets
reproduced!

17. Another Pollinator – note pollen on back legs

18. Protozoans in cow’s stomach
These protozoans along with
bacteria help the cow by
digesting cellulose; cows
don’t have the enzymes to
do this.
The protozoans and bacteria get a place to live and a continual food source. This is a valuable mutualistic relationship.

19. Ants and Acacia Trees Acacia trees are found in Central America.
Ants hollow out the
large thorns of the
plant for nests and
feed on sweet
secretions from the
base of each leaf and
on the protein rich
substance found on
the tips of the leaves,
The ants in return
protect the trees from
herbivores that would
eat the leaves. With a
movement of the
branch, ants emerge
and release a nasty
odor and attack the
herbivore.

20. The ants, again When an experiment was done and the ants were
poisoned, the
acacia trees
died from
being
overtaken
by other
plants and
herbivores.

21. OxPecker - Mutualism The oxpecker eats parasites on the mammal –
food for
the bird
and
removal of
danger
for the
mammal

22. More Ox (?) peckers

23. Another ox(?)pecker

24. Caterpillar Ant Mutualism

25. Cattle Egret - Commensalism
The cattle stir up
grasshoppers
and other
insects that the
egret likes to
eat. There is
no apparent
benefit to the
cow.

26. Commensalism
Commensalism is a relationship where one organism benefits and other is neither harmed nor benefited.
Few examples of commensalism exist because of the difficulty of showing that one of the organisms is not affected by the other. Some of the former cmomensalistic relationships may turn out to be mutualism or parasitism.

27. Commensalism – shark and remora
The remora
benefits by
getting food
from the
shark’s meal.
But there is no
apparent
benefit to the
shark.

28. Remora without its shark
Note the sucker on the head of the remora (or suckerfish)

29. Commensalism – whale and barnacle
The barnacle larvae swim around, attach to the whale, and form the adult. This habitat is a good one for providing food. The whale does not “appear” to be harmed.

30. Commensalism – limpets on mussel shell

31. Parasitism Adult wasps insert their eggs beneath the skin of the
hornworm larva.
The eggs hatch and
the young feed
hornworm until they
pupate as shown in
the photo. Although
the parasite is
harmful to the worm,
it is important in
controlling
hornworms in
agriculture.

32. Parasitism
Parasitism is a relationship where one individual benefits and the other is harmed. Parasites rarely kill their hosts because to do so would ultimately harm the parasite!
A tick!

33. Brood Parasitism - Cowbirds
females lay
their eggs (one
per nest) in the
nests of other
species. The
hatchling
cowbird
is big and gets
most of the
food.
This is because the foster birds tend to feed the largest mouth. The cowbird benefits and the other species is harmed.

34. Mistletoe – a plant parasite
Mistletoe lives off the branches and stems of Other trees. It can photo- synthesize a little but not enough to meet its needs. The tree can be very harmed.

35. Heartworms! The worm larvae are transferred from dog to
dog through the bite of
an infected mosquito.
The mosquito sucks
larval heartworms with
blood from an infected
dog. The mosquito then
bites another dog and
transfers these
microscopic larva as it
bites. During the next few
months, these larva
migrate through the dogs
body arriving at the heart
several months later
where they become
adults.

36. Predator prey
In this Predator-Prey relationship, the spider is eating an insect that it has trapped.

37. Predator-Prey
In a predator-prey relationship one organism benefits and the other is killed.

38. The Ultimate Predator – a Cheetah!