The Footprint of Urbanization
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Transcript of The Footprint of Urbanization
The Footprint of Urbanization
Changes in Land-use and Land- cover
• Global changes:1700-1990 (Meyer and Turner 1992)
– Cropland +392 - 466%
– Irrigated Cropland +2400%
– Closed Forest -15.1%
– Forest and woodland -14.9%
– Grassland/pasture -1%
– Lands drained 1.6 x 106 km2
– Urban settlement 2.5 x 106 km2
– Rural settlement 2.1 x 106 km2
(Lambin et al. 2001)
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
• 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
RelativeAbundance(birds countedwithin 50 mduring 10 mins)
What are the Mechanisms?
• 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
647m
Pacific Wren 2240-84237
Song Sparrow 1861-78683
2005
200629m
Adapters Wait Out Change
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
0
5
10
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20
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BrownCreeper
ChestnutBacked
Chickadee
HairyW oodpecker
Red-shaftedFlicker
PileatedW oodpecker
Red-breastedNuthatch
Me
an
No
. Pa
irs
pe
r 4
0 h
a
Densities Much Lower than Non-Settled Areas
Zarnowitz and Manuwal (1985)
This study – entire Site
This study – Forest only
(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?
(Marzluff 2005 Urban Ecosystems 8:157-177)
Projected Forest Decline
Some Winners May Accentuate Losses
Farwell and Marzluff2013, Biol. Conservation
What are the Mechanisms?
• Reproduction √• Dispersal• Survival √ √• Population Size √ √ √
• Future Directions– Primary Productivity– Facilitation– Competition– Coevolution with People
Wider View (Canada)
(Calvert et al. 2013. Avian Cons. And Ecol.)
A Bird Friendly Morality1. Thou shall not covet thy neighbor’s lawn.
2. Thou shall not allow thy cat to roam.
3. Thou shall make thy windows visible.
4. Thou shall not light the night sky.
5. Thou shall provide food and nest boxes.
6. Thou shall not kill native predators.
7. Thou shall abhor uniformity.
8. Thou shall provide safe passage across thy roadways.
9. Thou shall provide functional connections between terrestrial and aquatic worlds.
10. Thou shall nurture the human bond with nearby nature.