Habitat

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Habitat
Habitat physical conditions of the place an
organism lives (e.g., temperature range,
vegetation structure) Ecological niche the
resources that an animal must exploit for growth
and reproduction (e.g., available food, nest
sites, territory space)
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Generalized Forest Zones of the Washington
Cascades
Cross-section of Cascades
WEST
EAST
Alpine
Alpine
Spruce-fir
Mountain hemlock
Douglas-fir
Pacific silver fir
Ponderosa pine
Western hemlock
Shrub-steppe
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How Rain Shadows Form
Rainshadows (drier climate)
Air mass
Cascades
Olympics
Pacific Ocean
Puget Trough
Ellensburg
Ppt 10-12
Seattle
Ppt 100-200
Ppt 10-12
North Bend
Ppt 36
Ppt 100
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Community Succession
Natural succession after catastrophic fire all
original trees destroyed
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Community Succession
Natural succession after catastrophic fire some
original trees survive
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Community Succession
Forest development after a partial harvest (C)
or clearcut (D)
Note little understory
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Processes Habitat Selection
Basic Premises

• Mostly instinctive
• Some animals show more flexibility in preference
  than others.

Pygmy rabbit
Iiwi
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Habitat Selection Hierarchical Decision-making
Process (Hutto 1985)
Exploratory Assessment
Summer
Innate
Exploratory Assessment
Winter
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Processes Habitat Selection
Basic Premises

• Some animals show strong ability to adapt to new
  habitats

White-tailed deer
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Processes habitat selection
Basic Premises

• Some animals show strong ability to adapt to new
  habitats

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Processes Habitat Selection
Basic Premises

• Habitat choice is strongly influenced by
  vegetation or ground characteristics

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Factors That Initially Attract Birds And/or
Mammals to an Area

• Landscape and terrain
• Stimuli from nest-sites, den-sites
• Song posts (perches)
• Feeding drinking sites
• Food availability
• Possibly other animals- predators, competitors,
  ungulates

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Vegetative Characteristics of Habitat Used by
Birds
Complexity of the vegetation is important for
many species of birds

• Amount of vegetation layering
• Shrub height and cover
• Forest floor characteristics
• Tree canopy density

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Vegetative Characteristics of Habitat Used by
Birds
For cavity-nesting species

• Number and type of dead and dying trees
• Location of suitable trees and snags
• Forest floor characteristics
• Tree canopy density

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Studying Habitat Selection Use versus
Availability
Forest types
Shrub and grass
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Studying Habitat Selection Use versus
Availability

• Measure area of each habitat type available to
  animal
• Measure use of each type by animal

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(No Transcript)
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Used older forest stands more than available
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Some Population Attributes that Affect Habitat
Choice

• Ability to pioneer (colonize)
• Overpopulation (saturation leads to emigration)
• Territoriality and Fitness