14.1 Habitat And Niche
KEY CONCEPT
Every organism has a habitat and a niche.
14.1 Habitat And Niche
A habitat differs from a niche.
• A habitat is all of the abiotic and biotic factors in an area in
which an organism lives.
Eastern Bluebird Sialia sialis
Habitat includes fields of dense
grass. Open and partly open
country in a wide variety of
situations, often around human
habitation. Nests in buildings,
caves, crevices on cliffs,
burrows, and hollow trees,
rarely in trees with dense
foliage.
Habitat includes forest edge,
open woodland, and partly open
situations with scattered trees,
to riparian woodland, also pine
woodland .Nests are in natural
cavities, old woodpecker holes,
or similar sites, mostly 3-20 feet
(1-6 meters) above ground.
Barn Owl Tyto alba
14.1 Habitat And Niche
An ecological niche includes all of the factors that a
species needs to survive, stay healthy, and reproduce.
– food
– abiotic conditions
– behavior
Eats mainly small
mammals, especially
voles, birds can be taken
when small mammals are
scarce. Dense grass fields
are the chief foraging
habitat, pastures, grass
hayfields, and recently
abandoned agricultural
fields
An insectivorous or
omnivorous birds; often
flies from low perch to
ground to feed on beetles,
are territorial, prefer open
grassland with scattered
trees and are cavity
nesters
14.1 Habitat And Niche
Resource availability gives structure to a community.
Species can share habitats and
resources.
• Competition occurs when two species use resources in the
same way.
• Competitive exclusion keeps two species from occupying
the same niche.
• One species that is best suited to the niche will survive and
the other will die out (extinct) or be pushed into another
niche.
14.1 Habitat And Niche
• Competitive exclusion has different outcomes.
– One species is better suited to the niche and the other
will either be pushed out or become extinct.
– The niche will be divided.
– The two species will further diverge.
14.1 Habitat And Niche
Niche Partitioning
Niche is divided so that
all the species can
survive.
14.1 Habitat And Niche
Evolutionary response
Organisms evolve to fit a niche.
14.1 Habitat And Niche
• Ecological equivalents are species that occupy similar
niches but live in different geographical regions.
Madagascar
South America