Exploring the Redwoods to
understand
Habitat/ Niche
Resource Partitioning
Generalist vs. Specialist
The Redwood Forests
• Video Overview
Habitat vs Niche
• Habitat is the physical
location that an
organism occupies
• Niche- how an organism
makes its living. How it
obtains food, its
relationships with other
organisms, services it
provides the ecosystem,
all behaviors needed for
it to survive
Banana Slug
• Habitat
• Sides of Redwoods
• Redwood Forest Floor
•
•
•
•
Niche
Eats scat, leaves, fungus
Solitary
Uses sides of tree to
keep cool
• Camouflaged
Competitive Exclusion
• Two species that compete for the exact same
resources cannot stably coexist
• One species will always have a slight
advantage over the other
– One species evolves
• OR
– One species becomes extinct
“It’s a Slug Fest”
Spotted Leopard Slugs and Banana Slugs are thought to have
occupied the same habitats. The Spotted Leopard Slug left the
Redwood Forests are known to prefer gardens. In fact, most species of
leopard slugs are now associated with “human habitats”.
A Tale of three squirrels
Chickaree Squirrel
Northern Flying Squirrel
Western Gray Squirrel
Competition
• Two types of competition:
– Intraspecific- competition among members of the
same species
– Interspecific– competition among members of
different species
Changes
• The Law of Competitive Exclusion most likely
led to the three species of squirrels in the
Redwood Forests.
• All three new species then had to deal with
Interspecific Competition
• Otherwise they would be fierce competitors
A Tale of three squirrels
Chickaree Squirrel
DIURNAL
Northern Flying Squirrel
NOCTURNAL
Western Gray Squirrel
DIURNAl
A Tale of three squirrels
Chickaree Squirrel
Douglas Fir and White Pine
Cone Seeds
Northern Flying Squirrel
Eats Fungi
Western Gray Squirrel
Eats Redwood Pine Cone
Seeds
Resource Partitioning
Resource PartitioningHigh levels of specialization
That allow several species
To utilize different parts of the
Same resource and coexist
Within a single habitat.
Northern Flying Squirrel
Chickaree Squirrel
Western Gray Squirrel
There is a danger to Resource
Partitioning
• Generalist- these are
species that do not
have specific habitat or
food requirements. You
see these organisms
colonize large areas of
land…event he globe
• Example: Humans
• Specialist- require
special habitats or
specialized food
resources.
• Examples: Our squirrel
friends
• Endangered and
threatened Species
Side track….
• They are just to cool,
you gotta check this
out!
• Is it a Bird? Is it a plane?
No, it's a flying squirrel!
Producers
•
•
•
•
•
Redwood Tree
Moss
Fern
Shooting Star
Violet
First Order Consumers (Herbivores)
Second and Third order Consumers
Decomposers
Scavengers
Life on the Prairie
• As you watch note the following:
– Habitat= Prairie
– Niches
– Specific Feeding Relationships
– Law of Competitive Exclusion
• Interspecific and Intraspecific
– Resource Partitioning
An Evolutionary Side Note
• Gigantism and Dwarfism
• Foster’s Rule-also known as the island rule) is
a principle in evolutionary biology stating that
members of a species get smaller or bigger
depending on the resources available in the
environment.
• Hising Cockroaches
• Key Deer
• Komodo Dragon