Wildlife habits Ecology

1. Wildlife Habitats
Habitat Selection and
Habitat Manipulation

2. • A habitat is all aspects of the area
in which an organism lives- biotic
and abiotic
A niche? Niche is the functional
role and position of a species in its
environment that describes how
the species responds to the
distribution of resources and
competitors or predators.

3. Resource availability gives structure to a
community.
a. Species can share
habitats and resources.
b. Competition occurs
when two species use
resources in the same
way (Interspecific or
intraspecific).

4. Possible Outcomes of Species Competition
a. One species is better suited to the
niche and the other will either be
pushed out or become extinct
(Competitive exclusion).
b. The niche will be divided.
c. The two species will further diverge.

5. 14.1 Habitat & Niche / 14.2 Community Interactions
Habitat selection
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6. 14.1 Habitat & Niche / 14.2 Community Interactions
There are a number of confused terms
• Habitat use
• Habitat selection
• Habitat preference
• Habitat requirement
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7. 14.1 Habitat & Niche / 14.2 Community Interactions
Lets define them…
• Habitat use = occupation of a habitat without
any connotation of preference
implies used ‘for something’
• Habitat selection = implies choice among those
habitats available
individuals may search for certain habitats for
specific behaviors (breeding, feeding, resting)
-its use against availability
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8. 14.1 Habitat & Niche / 14.2 Community Interactions
Definitions cont:..
• Habitat preference = implies choice of one
habitat over another without regard to whether it
is available or not.
Preference exists even if habitat is not there.
• Habitat requirement = implies that the habitat
attribute is needed for survival.
Differs from preference in that you may prefer 1
among several types that all meet your
requirements
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9. 14.1 Habitat & Niche / 14.2 Community Interactions
How do animals select habitat ?
• Is habitat selection an innate ability or a learned
trait?
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10. 14.1 Habitat & Niche / 14.2 Community Interactions
How do animals select habitat ?
• Niche gestalt
(these are structural features of the
environment that allow a species to thrive
over and above those that allow it to persist).
• Competition and Predation effects on habitat
selection
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11. 14.1 Habitat & Niche / 14.2 Community Interactions
Levels of Habitat Selection
• At the broadest level habitat selection is
innate
• Evolution led constrain animals to certain
geographical boundaries
– within this ‘range of tolerance’ limited by
historical events, animals make choices
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12. 14.1 Habitat & Niche / 14.2 Community Interactions
Hierarchical levels of habitat selection
• Johnson (1980)
– 1st Order - physical or geographical range
– 2nd Order - home range of an animal or
group
– 3rd Order - habitat components within a HR
– 4th Order - actual food items etc.
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13. 14.1 Habitat & Niche / 14.2 Community Interactions
Diagram of hierarchical levels
• A = Continental
– 1st order
• B = Habitat
– 2nd order
• C = Components
– 3rd order
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14. 14.1 Habitat & Niche / 14.2 Community Interactions
Habitat selection leads to differential population
densities
• Not all parts of
distribution
have equally
good ‘habitat
quality’
• What factors
lead to
population
densities in a
species
habitats?
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15. 14.1 Habitat & Niche / 14.2 Community Interactions
13.1 Ecologists Study Relationships
Habitat manipulation

16. 14.1 Habitat & Niche / 14.2 Community Interactions
What is it?
• Modification of the natural environment to
achieve a certain human goal.
• Manipulation of agricultural areas and
surrounding environment with the aim of
conserving or augmenting populations of
particular species.

17. 14.1 Habitat & Niche / 14.2 Community Interactions
What aspects on the habitat?
Major components
• Food base –
• Water –
• Shelter -
• Space –

18. 14.1 Habitat & Niche / 14.2 Community Interactions
Always based on known systems
e.g.
• biogeochemical cycles
• Carrying capacity
• Predator-prey relationships
• Habitat preferences
• Climatic patterns
• projected response of the environment to
stimulation
etc

19. 14.1 Habitat & Niche / 14.2 Community Interactions
Habitat manipulation
What are the known
impacts of fire on
rangelands?
Grass rejuvination, spp diversity decrease, break seed
dormancy, control bushes, control pests,

20. 14.1 Habitat & Niche / 14.2 Community Interactions
Habitat manipulation
This river will tend
to be cool, and if
you want to
encourage open
water fish species?
What if the river
has been
experiencing a lot
of flactuations in
levels? Good for
spp?

21. 14.1 Habitat & Niche / 14.2 Community Interactions
Habitat manipulation
Milk cattle breeds tend to
love the pure grass
stands...so clearence of the
habitat and planting of some
grass species

22. 14.1 Habitat & Niche / 14.2 Community Interactions
Habitat manipulation
Sea otters sometimes
needs special bank
sides for their habitats.
Logs crossing rivers are
good – micro-bridges for
small animals to cross
over
River beds can be
modified for particular
fish species

23. 14.1 Habitat & Niche / 14.2 Community Interactions
• Even the weeding or
bush control is a
form of habitat
manipulation
Habitat manipulation

24. 14.1 Habitat & Niche / 14.2 Community Interactions
Question
• Distinguish between: a) Habitat requirement
and Habitat selection
• b) Habitat degradation and habitat
manipulation

25. 14.1 Habitat & Niche / 14.2 Community Interactions
End...Questions