Download Species Competition

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Interspecific Competition
Competition between 2 or more species for:
Food
Space
Limited resources
SPECIES COMPETITION
Ecological Niche
Role the species plays in the environment
When they compete, these niches overlap
The more they overlap the more they compete
Humans are competing with species for food, space
and other resources
Predator-Prey Relationship
One member feeds on another
Predators usually kill the sick, weak or aged.
This helps to let the rest of the prey have
greater access to the available food supply.
It also improves the genetic stock.
Symbiosis
Long term interaction between species
Parasitism –when 1 species (parasite) feeds on part of
another species (host) by living on or in it for a large
portion of host's life.
Commensalism – benefits one species but doesn't harm
or help the other
Mutualism – both species benefit
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Parasites: Sponging Off of Others
Mutualism: Win-Win Relationship
Although parasites can harm their hosts, they can
promote community biodiversity.
Two species can
interact in ways
that benefit both
of them.
Some parasites live in host (micororganisms,
tapeworms).
Some parasites live outside host (fleas, ticks, mistletoe
plants, sea lampreys).
Some have little contact with host (dump-nesting birds
like cowbirds, some duck species)
Commensalism: Using without Harming
Some species interact
in a way that helps
one species but has
little or no effect on
the other.
(a) Oxpeckers and black rhinoceros
Population Growth Cycle
Limited Resources
A population can grow until competition for limited
resources increases & the carrying capacity (C.C.) is
reached.
Typical Phases
1. The population overshoots the C.C.
2. This is because of a reproductive time lag (the
period required for the birth rate to fall & the
death rate to rise).
3. The population has a dieback or crashes.
4. The carrying capacity is reached.
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Relationship to Human Population
Growth
Infectious disease can
control humans. Ex.
the Bubonic plague.
Resource Partitioning
Occurs when species competing for similar scarce
resources evolve specialized traits that allow them
to share
Reduces competition
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