Download Competition - Warren County Schools

The Cape May
warbler feeds
at the tips of
branches near the
top of the tree.
The bay-breasted
warbler feeds in the
middle part of the tree.
Competition
Different species can share the same habitat, such as the many
animals that live in and around the saguaro. Different species
canalso share similar food requirements. For example, the redtailed hawk and the elf owl both live on the saguaro and eat
similarfood. However, these two species do not occupy exactly
the same niche. The hawk is active during the day, while the
owlis active mostly at night. If two species occupy the same
niche, one of the species will eventually die off. The reason for
thisiscompetition, the struggle between organisms to survive in
ahabitat with limited resources.
An ecosystem cannot satisfy the needs of all the living things
ina particular habitat. There is a limited amount of food, water,
andshelter. Organisms that survive have adaptations that enable
them to reduce competition. For example, the three species of
warblersin Figure 12 live in the same spruce forest habitat. They
alleat insects that live in the spruce trees. How do these birds
avoid competing for the limited insect supply? Each warbler
"specializes"in feeding in a certain part of a spruce tree. By findingtheir own places to feed, the three species can coexist .
..J~!J~.lMr!.1\!.C!. Many plants use chemicals to ward off their
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CHEMISTRY
competition. Plants often compete with one
another for growing space and water. Some shrubs release toxic,
or poisonous, chemicals into the ground around them. These
chemicals keep grass and weeds from growing around the
shrubs, sometimes forming a ring of bare ground a meter or
twowide.
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The yellowrumped warbler
feeds in the lower part
of the tree and at the
bases of the middle
branches.
Figure 12 Each of these warblers
occupies a different niche in its
spruce tree habitat. By feeding in
different areas of the tree, the birds
avoid competing with each other
for food.
Why can't two species occupy the same niche?
Chapter 7
E. 33