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What is Dynamic Equilibrium?
What is a Population?
What is a Community??
What is an Ecosystem?

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By the end of today’s lesson you should be able to:
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Explain how organisms can be classified based on their degree of risk
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Describe what an indicator species is and why they are important
Identify factors that can cause the disappearance of different organisms

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Secure- no current risk to population
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Pintail Duck
Whitetail Deer

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Special Concern- numbers are declining at the range/ fringe of the area
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Bobcat
Lynx
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Bald Eagle

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Threatened- species may become endangered if threatening conditions are not reversed
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Wolverine (<1000)
Grizzly Bear
Western Hognose Snake

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Extirpated- a species no longer exists in one particular area, but is still found in other areas
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Black-footed Ferret
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Takhoka Daisy
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Only ever found in Canada along the Belly
River
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Cannot be found in that location anymore

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Endangered- a species is close to extinction in all parts of their natural habitat
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Burrowing Owl
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Whooping Crane
Swift Fox
Northern Leopard Frog

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Extinct- a species no longer exists
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Passenger Pigeon
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Once the most abundant bird in North
America
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Hunted for meat by the poor and slaves

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Exotic or Alien- non native species introduced by humans
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Ring-necked Pheasant
Black Rat
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Asian Carp

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Accidental/ Vagrant
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Present through migration
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Arctic Fox

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Species of organisms that provide an early warning that an ecosystem is being affected by some factor
These species are particularly sensitive to small changes in the ecosystem.
Amphibians, fish, algae, and plants are good indicator species.
Brainstorm: why do you think this is?

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Herbivore: an animal that eats only plants
Carnivore: an animal that eats only other animals
Omnivore: an animal that eats both plants and other animals

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During a frog’s life cycle it is part of two separate food chains (adult, tadpole)
Tadpoles eat dead algae (detrius), and are eaten by large insects that live in the water
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Detritus: waste from plants and animals, including their dead remains
Decomposers: an organism that feeds on detritus
Adult frogs eat insects, and small fish and in turn are eaten by large fish, birds, etc.

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Why do you think frogs are disappearing?
Loss of habitat?
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Habitat: a place or type of environment with conditions suitable for the survival of an organism or populations of organisms
Air/water quality?
Climate change?
UV radiation ?
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UV (Ultraviolet) Radiation: electromagnetic radiation from the sun that can cause burning of the skin or cellular mutations
Ozone (O
3
): an inorganic molecule. A layer of ozone found in the stratosphere helps screen out UV radiation

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As a class read page 15
Take a Position #1

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Complete the following questions on page 15: UTI 1 and 2
Complete the following questions on page 16: 1, 3a
Complete the following questions on page 18 – 19: 1-8, 12, 15,

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Review the terms we have discussed and learned