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

15

20

25

30

35

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.