Ch. 5: Predators, Prey

1
Ch. 5 Predators, Prey Competition

• Vocabulary
• ecosystem, predator, prey, resource, compete,
  survive

2
Ecosystems

• All of the things on Earth, both living and
  non-living, are part of an ecosystem.
• Everything from the plants and animals that live
  in an area to the water, sunlight, soil, rocks,
  and air make up an areas ecosystem.
• There are many different types of ecosystems on
  the planet.

3
Ecosystems Tropical Rainforest

• Tropical Rainforests get a lot of rain every
  year.
• Thats why they are
• called rainforests.
• They are also usually
• located in the area of the
• Earth known as the tropics.
• Tropical rainforests have the most biodiversity
  of any place on the planet.
• Because there is so much rain, fruit trees
  produce all year long, which leads to more
  insects, which leads to more birds, which leads
  to more predators, on and on and on.

4
Ecosystems Subtropical savannas

• Subtropical savannahs are flat grasslands usually
  found near deserts outside the tropics.
• Many different types of animals live on
  grasslands and have adapted to living in tall
  grass.
• These adaptations usually involve raising the
  head to see above the grass, or colorations that
  allow them to blend in with tall grasses.

5
Ecosystems Deserts

• Deserts are dry arid places, that sometimes have
  sand and sometimes do not.
• Because of the lack of water all the organisms
  that live in the desert have adapted to gather
  water from other sources than what we normally
  do.
• For example the pack rat gets its water from
  eating plants and the dung beetle allows dew to
  collect on it every morning and drinks it when
  the water bubbles get big enough to gather.

6
Ecosystems Oceans

• Oceans make up 75 of the earths surface.
• Most of the water on Earth is located in the
  oceans of the world.
• The plants and animals that live in the ocean
  have adapted the ability to either float or swim.
• Some have even developed the ability to breathe
  underwater by way of gills, which are different
  than the lungs you have.

7
Ecosystems Temperate Grasslands

• Temperate Grasslands are large plains of grass
  found in North America, Asia, and Australia.
• Because of the winds that sweep across these
  grasslands, not many trees grow here.
• Most of the animals who live on temperate
  grasslands have adapted the ability to run
  quickly away from predators and large shaggy
  coats for the colder winters.

8
Ecosystems Temperate Forests

• Temperate forests are located outside of the
  tropics, but below the polar regions of the
  planet.
• Temperate forests have moderate summers and cold
  winters.
• Most of the plants that live in temperate forests
  have adapted leaves that shed in the winter.
• Most of the animals that live in temperate
  forests have adapted to this lack of food by
  entering hibernation in the winter.

9
Ecosystems Coniferous Forests

• Coniferous Forests form the boundaries between
  Temperate Forests and the Polar Regions of the
  world.
• Coniferous plants are specifically adapted to
  deal with cold weather better than than their
  temperate cousins.
• Coniferous plants have small needle-like leaves
  that do not shed, so that they can absorb as much
  sunlight as possible when it is available.

10
Ecosystems Polar Regions

• Polar areas, or tundra, are found near the north
  and south poles.
• The summers are very short and winters can be
  dark all day long for up to 6 months.
• Often in these areas there is a lot of snow.
• The plants have adapted to be short and can grow
  very fast on the little sunlight they can get
  during the spring and summer.
• Animals are often white to blend in with the snow
  and small because of the lack of plant life, but
  have an insulating layer of fat called blubber in
  order to stay warm.

11
Predators and Prey

• We know that plants can make their own food using
  chlorophyll.
• Animals, on the other hand, cannot.
• Because of this, animals fall into one of two
  categories predator or prey.
• Animals that eat other animals are called
  predators.
• Animals that are hunted by other animals are
  called prey.
• Sometimes, one animal can be both a predator of
  some animals and prey to others.

• Snakes are both predator and prey. They eat
  small animals like rats and mice, but they are
  also eaten by other animals, like hawks.

12
Predators and Prey

• In a healthy ecosystem, predators and prey are
  pretty balanced.
• Usually there are lots of prey animals, and a few
  predators to feed on them.
• But many things can alter an ecosystem and throw
  it out of balance.
• Animals in an ecosystem that is thrown out of
  balance are not dumb.
• Usually, they will not remain in an area that
  lacks what they need and they will move away.

13
Predators and Prey Sickness

• If a disease infects an ecosystem, it can be
  thrown out of balance.
• Lets go back to the hawk and mouse example from
  earlier
• A disease affects the mice in the forest, killing
  a lot of them.
• What happens to the hawk population?
• Or, a disease affects the hawks in the forest.
• What happens to the mouse population?

14
Competition

• Sunlight, food, water, and living space are
  needed for all living things to survive.
• But oftentimes, species of plants and animals all
  want the best of each of these.
• In order to get the best food, water, sunlight
  patch, or living space animals and plants must
  compete with each other.

15
Examples of Competition

• Animals compete most often for food
• Snakes, hawks and owls all eat mice.
• If a disease kills most of the mice in the forest
  and the owls are the ones that are able to catch
  more mice than the hawks or the snakes, what
  happens to the hawk and snake populations?
• Plants compete, too
• Trees have large roots that stretch for long
  distances.
• They need a lot of water and nutrients from the
  soil.
• They adapted to have large branches and many
  leaves to shade the area around their roots, so
  that other plants wont get enough sunlight at
  the bottoms of the trees and take the nutirents
  in the soil from them.

16
Questions about Chapter 4

• 1. Foxes eat rabbits. What happens to the foxes
  if something happens to the grass that the
  rabbits eat?
• 2. Frogs eat insects. If the number of frogs
  goes down, what happens to the number of insects?
• 3. In the Great Plains ecosystem, wolves and
  mountain lions eat buffalo, antelope, and deer.
  The deer, buffalo, and antelope eat plants.
  Which animals are the predators?
• 4. Give and example of two living things
  competing for a resource.
• 5. Name 5 nonliving resources in an ecosystem.