Download limiting factors

Journal 4/12/17
What happens to your physical body after you die? Why
does this happen?
Objective
To learn about specific
interactions animals have in
their environment
Tonight’s Homework
p 471: 1, 2, 3, 5
Niches and Limiting Factors
We said before that we can have producers and
consumers. However, there are a number of
other relationships between animals we can
investigate.
Niches and Limiting Factors
We said before that we can have producers and
consumers. However, there are a number of
other relationships between animals we can
investigate.
Neutralism:
There are many species in ecosystems that
don’t directly affect each other. For example, if
we have a bird that eats only seeds, and a lizard
that eats only insects, the two never directly
interact. Your exhibit will likely have a lot of
these since they shouldn’t hurt or attack each
other.
Niches and Limiting Factors
Competition:
Many animals that eat the same thing are in
competition. Both hyenas and lions eat
springbok and zebras. They have to compete
sometimes to see who gets the most. Your
exhibit can have some of this as well, since we
assume you’ll feed your animals.
Amensalism and Commensalism:
These happen when one organism hurts or helps
another without the second hurting or helping
the first one back. Mold killing other things
nearby would be amensalism, while lions leaving
remains behind for vultures would be
commensalism.
Niches and Limiting Factors
Parasitism:
In parasitism, one creature (the parasite), lives
by harming – but usually not killing – a second
creature (the host). The parasite is usually
much smaller than the host. Examples include
mosquitoes and leeches.
Mutualism:
In mutualism, both creatures benefit from
working together. Some of these “teams” are
necessary. Termites can’t digest wood without
bacteria to help. Some are optional. Sometimes
birds will clean a hippo’s teeth. The birds get a
free meal and the hippo gets annoying stuff off
its teeth.
Niches and Limiting Factors
[pictures]
Niches and Limiting Factors
The stuff before explains how animals interact
with each other. But animals can interact with
their environment as well.
The specific part of an ecosystem that an animal
inhabits is called its habitat. The way that the
animal interacts with the ecosystem is called its
niche (pronounced “nitch”).
Habitats can range from being as simple as a
cave for a bat, to a specific temperature and
type of water for a frog.
Niches and Limiting Factors
In an ecosystem, every creature fills a niche.
Think of this sort of like a creature’s job. What
role does the creature fill that’s important to the
ecosystem?
For example, look at bees. Without bees, plants
can’t pollinate and bears no longer have one of
their sources of food. The bee fills a niche that
helps both other organisms (among others).
The kinds of niches we find in an ecosystem
help determine the organisms that will live in
the ecosystem. If a field needs a pollinator, bees
could move in and fill that niche.
Niches and Limiting Factors
But we can’t just add more and more niches to
an ecosystem. Remember the stuff we said
about energy? Eventually, we won’t have
enough for everyone. This brings us to limiting
factors.
Every ecosystem can have dozens of potential
limiting factors. Take a desert for example. A
cactus has few predators and gets tons of
sunlight. So why doesn’t it grow tall super fast?
Because it lacks water. In a desert, lack of water
is often a limiting factor. We could also have too
much water. Give a cactus too much and it’ll
drown.
Niches and Limiting Factors
There are many possible limiting factors:
Temperature
Water
Brightness
Minerals
Air
Physical Space
Sound
Etc etc.
A lot of limiting factors and a lot of animals are
connected. If rabbits multiply in a field, they
could eat all the grass, which leaves not enough
for the cows, which start to die out. Then we get
more foxes as they eat all the dead cows, which
reduces rabbits again. That sort of thing.
Adding to your Project
We can add today’s concept to your project. Be thinking
about the niches and limiting factors for each of your
animals. This may require some research but may be
something you can do with mostly just using your brain.
Lastly, think about relationships between animals. Most will
exhibit neutralism, but not all!
Exit Question
Imagine we’re looking at 2 animals. The animals interact
and both get something positive out of the relationship.
What kind of relationship is this?
a) Neutralism
b) Competition
c) Amensalism or Commensalism
d) Predation
e) Parasitism
f) Mutualism