Transcript Document

The Footprint of Urbanization
Changes in Land-use and Land- cover
• Global changes:17001990 (Meyer and Turner 1992)
(Lambin et al. 2001)
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Cropland
Irrigated Cropland
Closed Forest
Forest and woodland
Grassland/pasture
Lands drained
Urban settlement
Rural settlement
+392 - 466%
+2400%
-15.1%
-14.9%
-1%
1.6 x 106 km2
2.5 x 106 km2
2.1 x 106 km2
Settlement Affects Native Habitat
• Habitat Loss
• Reduced connection
among remaining
patches
• Perforation of large
patches
• Introduction of exotics
• Degradation of
remaining habitat
Settlement Benefits Some Wildlife
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Reduced predation
Reduced climatic extremes
Available water
Supplemental food
New nest sites
Increased edge and vegetative diversity
What Can
We Learn
From A
Decade of
Work in
Seattle?
Insights from:
Heather Cornell,
Roarke Donnelly, Kara
Whittaker, Cara Ianni,
John Withey, Tina
Blewett, Jack DeLap,
Laura Farwell, Dave
Oleyar, Jorge
Tomasevic, Thomas
Unfried, Stan Rullman
Change is Rapid and Dramatic
Communities are of Similar Structure,
But Different Composition
As Urbanization Increases and Forest is Reduced, Bird
Diversity Increases, then Decreases
(Marzluff 2005)
• Extinction (local
extirpation) and
colonization
determine the
pattern of
diversity along a
gradient of
urbanization
Extinction and Colonization
Relative
Abundance
(birds counted
within 50 m
during 10 mins)
What are the Mechanisms?
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Reproduction
Dispersal
Survival
Population Size
Study Area
From 1999 to 2009,
we count, map,
band, and resight
birds within forest
patches from 3
landscape types:
•Forest reserves (5)
•Developed
Subdivisions (9)
•Changing
landscapes (13)
Reserve sites are primarily
forested.
Changing sites are undergoing
residential development
during the study
Developed sites are older
residential areas built prior to
the onset of study.
A Childhood Question
2003
2005
Pacific Wren 2240-84
Adapters Wait Out Change
Song Sparrow 1861-78683
2005
2006
Avoiders Move During Development
Monitoring Productivity and Survivorship
Productivity---Territory success and fledgling
estimates via spot mapping and nest monitoring.
Color-banded individuals of 7 species:
# Colorbanded
Individuals
# Territories/Nests
Monitored
American Robin
289
375
Bewick’s Wren
160
210
Dark-eyed Junco
141
339
Song Sparrow
1177
867
Spotted Towhee
533
848
Swainson’s Thrush
647
433
Winter Wren
195
552
A Diversity of Nest Predators
Estimating survival in different landscapes:
Yearly encounter histories based on recapture and resighting of
colorbanded individuals.
Used Cormack-Jolly-Seber model in Program MARK and RMARK.
Best model based on AICc included: species, landscape, and age
(juvenile and adult).
Survival (apparent) differed by species and also by landscape for
some species
Photo by T. Unfried
Landscape Specific Survival
Densities Much Lower than Non-Settled Areas
Mean No. Pairs per 40 ha
35
This study – entire Site
This study – Forest only
Zarnowitz and Manuwal (1985)
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25
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Brown
Creeper
Chestnut
Backed
Chickadee
Hairy
Woodpecker
Red-shafted
Flicker
Pileated
Red-breasted
Woodpecker
Nuthatch
(Blewett and Marzluff 2005 Condor 107:678-693)
Population
Size is a
Critical
Determinant
of Whether
Species Adapt
or go Extinct
in Urban
Environments
(Marzluff 2012)
Expected
Changes
(Hepinstall et al. 2008)
Spatial Changes
Winners
And Losers
Pacific-slope
Flycatcher
Approaching a Tipping Point?
Projected Forest
Decline
(Marzluff 2005 Urban Ecosystems 8:157-177)
Some Winners May Accentuate
Losses
Farwell and Marzluff
2013, Biol. Conservation
What are the Mechanisms?
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Reproduction √
Dispersal
Survival √ √
Population Size √ √ √
• Future Directions
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Primary Productivity
Facilitation
Competition
Coevolution with People
Wider View (Canada)
(Calvert et al. 2013. Avian Cons. And Ecol.)
A Bird Friendly Morality
Thou shall not covet thy neighbor’s lawn.
Thou shall not allow thy cat to roam.
Thou shall make thy windows visible.
Thou shall not light the night sky.
Thou shall provide food and nest boxes.
Thou shall not kill native predators.
Thou shall abhor uniformity.
Thou shall provide safe passage across thy roadways.
Thou shall provide functional connections between
terrestrial and aquatic worlds.
10. Thou shall nurture the human bond with nearby nature.
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