Download Chapter 8, Section 2 Notes

Bellringer
“As more individuals are produced that can possibly
survive, there must…be a struggle for existence,
either one individual with another of the same
species, or with the individuals of distinct species,
or with the physical conditions of life.”
- Charles Darwin
How does this quote
relate to niches and
competition?
Section 2
How Species Interact with
Each Other
I. An Organism’s Niche
niche the unique role of a species within an
A. _____
ecosystem
1. A niche includes an organisms:
a. physical home
b. environmental factors
c. species interactions
2. Habitat is different from niche
a. Habitat is location
3. Think of a niche as the organism’s job or
function
B. Niche example, Fruit Bat:
1. Lives in trees and
caves
2. Pollinates flowers
3. Spreads seeds
4. Interacts with hawks
and owls
II. Ways In Which Species Interact
Competition relationship in which different
A. ___________
individuals or populations attempt to use the
same limited resource
1. Can occur:
a. Between species
b. Within species
c. Indirectly
B. Between species:
1. Lions, Hyenas, and Cheetahs all compete for
the same food on the African savannah’s
C. Within species:
1. Two different loblolly pines growing close to
each other
a. Think of this as more of a resource
limitation
III. Indirect Competition:
A. Two closely relates species sharing a habitat
resulting in Niche restriction or Niche
differentiation: Examples…
1. Both mice and man will consume crops such
as corn, however in this relationship these
organisms will rarely interact
2. Two monkey species feed at different
heights within a tree
3. Two species of mice, one nocturnal and one
diurnal, both feed on insects. They feed at
different times
IV. Predation, Parasitism, Mutualism, and
Commensalism
A. Predator/Prey – One organism eating another
Example: snake (predator) eating a mouse
(prey)
B. Parasitism – An organism that takes
nourishment from an organism
1. Two parts:
a. Parasite – organism that feeds on
another organism
b. Host - organism that is providing
nourishment to the parasite
2. Different from a predator b/c the parasite
spends all or most of its life in or on the host
C. Mutualism – Two organisms living in
harmony helping each other out
1. A butterfly and a flower. How do they
help each other?
D. Commensalism – One species benefits, the
other is not harmed but doesn’t benefit
Describe the relationship between the following
organisms. How are each an example of
commensalism?