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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 10 6 km 2

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The Footprint of Urbanization

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  1. The Footprint of Urbanization

  2. 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)

  3. Settlement Affects Native Habitat • Habitat Loss • Reduced connection among remaining patches • Perforation of large patches • Introduction of exotics • Degradation of remaining habitat

  4. Settlement Benefits Some Wildlife • Reduced predation • Reduced climatic extremes • Available water • Supplemental food • New nest sites • Increased edge and vegetative diversity

  5. 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

  6. Change is Rapid and Dramatic

  7. Communities are of Similar Structure, But Different Composition

  8. As Urbanization Increases and Forest is Reduced, Bird Diversity Increases, then Decreases (Marzluff 2005)

  9. Extinction (local extirpation) and colonization determine the pattern of diversity along a gradient of urbanization

  10. Extinction and Colonization

  11. What are the Mechanisms? • Reproduction • Dispersal • Survival • Population Size

  12. 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)

  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.

  14. Monitoring Productivity and Survivorship Productivity---Territory success and fledgling estimates via spot mapping and nest monitoring. Color-banded individuals of 7 species:

  15. A Diversity of Nest Predators

  16. Landscape specific productivity estimates : From spot-mapping data and nest monitoring Territory success rates Number of fledglings/ successful nest We used these numbers to get estimate of fecundity

  17. Landscape specific productivity estimates : Most relationships are as expected WIWR surprising

  18. 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

  19. Landscape Specific Survival Consistent with decline of forest species and increase in Bewick’s Wrens in developed areas

  20. Estimating Juvenile Survival--Improved estimation using Telemetry (Whittaker and Marzluff 2008) American Robin = 25-50%, not responsive to forest Song Sparrow = 48%, declining with loss of forest Spotted Towhee = 33%, declining with loss of forest Swainson’s Thrush = 42%, not responsive to forest

  21. Using adult survival, juvenile survival, and fecundity we estimate λ, the intrinsic population growth rate for each species in these three landscapes using Ramas GIS. Source/ growing populations Stable population Sink / declining For each species/landscape we estimated lambda using the mean parameter estimates and the upper CI bound value for each parameter.

  22. This study – entire Site This study – Forest only Zarnowitz and Manuwal (1985) Densities Much Lower than Non-Settled Areas (Blewett and Marzluff 2005 Condor 107:678-693)

  23. Population Size is a Critical Determinant of Whether Species Adapt or go Extinct in Urban Environments (Marzluff in press)

  24. Expected Changes (Hepinstall et al. 2008)

  25. Spatial Changes

  26. Winners

  27. And Losers Pacific-slope Flycatcher

  28. Approaching a Tipping Point? Projected Forest Decline (Marzluff 2005 Urban Ecosystems 8:157-177)

  29. Some Winners May Accentuate Losses Farwell and Marzluff 2013, Biol. Conservation

  30. What are the Mechanisms? • Reproduction √ • Dispersal • Survival √ √ • Population Size √ √ √ • Future Directions • Primary Productivity • Facilitation • Competition • Coevolution with People

  31. Wider View (Canada) (Calvert et al. 2013. Avian Cons. And Ecol.)

  32. 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. • Thou shall nurture the human bond with nearby nature.

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