1. COMMUNITY INTERACTIONS

2. the area where an organism lives,
Habitat –
the area where an organism lives,
including the biotic and abiotic factors.
The organism’s “address”.
They both live in the temperate forest.

3. the range of physical and biological conditions
Niche –
the range of physical and biological conditions
in which a species lives and the way a species
obtains what it needs to survive and reproduce.
A species niche includes water, nutrients, food,
space, shelter, temperature, moisture, and mates.

4. They both eat mice but at different time of day.
Eagle feeds
during the day.
Owl feeds
at night.

5. Example of niche:
Three species of warblers all live in the same trees and feed on insects. But one species feeds on the high branches, one species feeds on the low branches, and the other species feeds in the middle.

6. Example of niche:

7. Specialized Feeding Niches of Various Bird
Species in a Coastal Wetland
Herring gull is a tireless scavenger
Brown pelican dives for fish, which it locates from the air
Ruddy turnstone searches under shells and pebbles for small invertebrates
Avocet sweeps bill through mud and surface water in search of small crustaceans, insects, and seeds
Dowitcher probes deeply into mud in search of snails, marine worms, and small crustaceans
Black skimmer seizes small fish at water surface
Figure 4.16 Various bird species in a coastal wetland occupy specialized feeding niches. This specialization reduces competition and allows for sharing of limited resources.
Flamingo feeds on minute organisms
in mud
Scaup and other diving ducks feed on mollusks, crustaceans, and aquatic vegetation
Louisiana heron wades into water to seize small fish
Oystercatcher feeds on clams, mussels, and other shellfish into which it pries
its narrow beak
Knot (sandpiper) picks up worms and small crustaceans left by receding tide
Piping plover feeds on insects and tiny crustaceans on sandy beaches
Fig. 4-16, p. 92

8. Range of tolerance
Tolerance- the ability of an organism to survive and reproduce under a range of environmental conditions.
# of organisms
temperature
Organisms become fewer as conditions move toward either extreme of the range.

9. Range of tolerance Some organisms have a Some organisms have a
broad range of tolerance and can better tolerate
changes in environmental
factors.
Some organisms have a
narrow range of tolerance
and are very sensitive
to the smallest change
in environmental factors.

10. Competition
When organisms attempt to use the same resource, in the same place at the same time, competition exists.
Animals compete for
resource such as food,
mates, places to live
and raise their young.
Competition can occur between members of the same species as well as members of different species.

11. Most Species Compete with One Another for Certain Resources
Competition
Weeds compete
with garden plants
Lynx and foxes
compete for prey
Bison and deer
compete for grass

12. Direct competition between different species almost always
Paramecium aurelia
Two species competing for the same limited resource cannot coexist in the same place. One species will use the resource more efficiently and thus reproduce more rapidly. Eventually, the best competitor will eliminate the other.
Paramecium caudatum
Direct competition between
different species almost always
produces a winner and a loser
--- the losing species dies out.

13. Most Species Compete with One Another for Certain Resources
Competition usually involves the ability of one species to become more efficient than another species in getting the limited resource.
The other species must:
move to another area
adapt by shifting its feeding habits or behavior through natural selection to reduce or alter its niche
suffer a sharp population decline
become extinct.

14. Competition Natural selection works to modify their niches in an
attempt to reduce or
eliminate competition

15. occupy a different niche?
Why do these warbler
occupy a different niche?
Natural selection acts to minimize/decrease competition.

16. Natural selection acts to minimize/decrease competition.
Fruit and seed eaters
Insect and nectar eaters
Honeycreepers
Greater Koa-finch
Kuai Akialaoa
Amakihi
These honeycreepers in
Hawaii evolved from a
single ancestor. Through
natural selection, each
species evolved a
specialized beak to take
advantage of certain types
of foods such as specific
types of insects, nectar
from particular types of
flowers, and certain types
of seeds and fruits.
Kona Grosbeak
Crested Honeycreeper
Akiapolaau
Natural selection acts to minimize/decrease competition.
Figure 5.3 Specialist species of honeycreepers: Through natural selection, different species of honeycreepers have shared resources by evolving specialized beaks to take advantage of certain types of food such as insects, seeds, fruits, and nectar from certain flowers. Question: Look at each bird’s beak and take a guess at what sort of food that bird might eat.
Maui Parrotbill
Apapane
Unkown finch ancestor
Fig. 5-3, p. 104

17. Competition Between Two Species of Barnacles

18. Predation is an interaction in which one animal (predator)
 Living Relationships
Predation is an interaction in which one animal (predator)
captures and feeds on another animal (prey).
Predator – are animals that kill and eat other animals.
Prey – the animals that predators eat.
Predators can affect
the size of prey populations
and determine the
places prey can live.

19. Sometimes changes in the population of a single species, called a keystone species, can cause dramatic changes in the structure of the community.
Example: sea otters – a keystone species.

20. Example: sea otters – a keystone species.
Sometimes changes in the population of a single species, called a keystone species, can cause dramatic changes in the structure of the community.
Example: sea otters – a keystone species.
Sea otters prey on sea urchins.
Sea urchins in turn, are
herbivores that feed on kelp.
A century ago, sea otters were
nearly eliminated by hunting.
As a result, the urchin population skyrocketed.
The urchins devoured the kelp forest.
The other animals that also live in the kelp forest also disappeared.

21. Symbiosis is any relationship in which there is
Many organisms form living relationships with other organisms.
These relationships may enhance the organism’s chance of survival.
Symbiosis is any relationship in which there is
a close and permanent association among
organisms of different species.
- - - “ living together”

22. a symbiotic relationship in which both species benefit.
Mutualism –
a symbiotic relationship in which
both species benefit.
Example: sea anemone and clownfish

23. Mutualism
Protists inside gut of termites

24. Commensalism – a symbiotic relationship in which one species benefits
and the other species is neither helped nor harmed.
Example: Grey whales and barnacles

25. Commensalism
Epiphytes

26. Parasitism – a symbiotic relationship in which one organism
derives benefit at the expense of the other.
Parasite benefits….host is harmed.
Example: Tapeworms and mammals

27. Parasitism Parasite rarely kills the host Parasite is usually much
smaller than the host

28. Nonnative species/Invasive species
Species that normally live and thrive in ecosystem
Nonnative species/Invasive species
-- Species that migrate into or are introduced
(deliberately or accidentally) into an ecosystem
-- also called: invasive, alien, and exotic species
Some are beneficial: food crops, flowers, animals like cattle, chickens, and fish
Some are harmful: compete with native species and reduce a communities native species. They often don’t face their native predators or disease to keep their populations in check and often out-compete the native species.

29. Nonnative/Invasive Species
Zebra mussels
Invasive species out-compete the native species,
they cause decline in the numbers of native species,
thereby decreasing biodiversity.