1. Sprawl and Fragmentation: How Much Development Deters Native Bird Species? Mary Ann Cunningham, Jake Hoffman Vassar College 1940 19702004 Built Tax Parcels Dutchess County NY

2. Questions: 1. Are native, woodland bird species inhibited by urbanization on the urban fringe? 2. Which gradients of urbanization are most important in predicting these species? (road density, tree cover, built density, proximate conditions) 3. Can easily-calculated measures, e.g. focal statistics, support multiple-scale investigations? (as alternative to digitizing/interpreting landcover data)

3. Study area approx 14 x 6 km (85 km 2 ) Study Area Poughkeepsie, NY

4. Representative of the peri-urban region

5. Methods: Point counts (5 min, 100 m radius) Distributed at 500 m intervals on E-W transects Explanatory variables: Proximate habitat: % cover (grass, shrub, trees, pavement); feeder (p/a), tree hights Calculated %road area (moving window/focal statistics over study area)

6. Euclidean distance to nearest road (distance function)

7. Average built parcel size (  built density) Interpolated surface from tax parcel centroids using parcel size as value (natural neighbor interpolation)

8. Digitized Tree cover  %trees at 4 scales

9. 300 m600 m900 m1200 m

10. Results: 84 observations 34 species, using P/A measures, most < 10 occurrences Distance to Roads (m) Average Parcel Size (ha) % Road area, 300 m, 600 m, 900 m radius 050100 0400800 08001600

11. ANOVA: indicates difference in variable value between presence and absence observations

12. Results: Bird counts: 84 observations 34 species, using P/A measures, most < 10 occurrences

13. Results: Bird counts: 84 observations 34 species, using P/A measures, most < 10 occurrences ANOVA: indicates difference in variable value between presence and absence observations

14. Significant Results (small sample sizes make results provisional!) (using Chi2 or backwards anova) Species NTempFeederGrassTreesShrubsPavemtPctRoads (300 m) PctRoads (600 m) PctRoads (900 m) Distance to roads Parcel size American Crow 56.021+.008-.038-.015+.0006+.0016+ Black-capped Chickadee 44 White-breasted Nuthatch 20.016-.003+ European Starling 14.07<.0001+ Tufted Titmouse 14.086-.048- Northern Cardinal 13.005+.013+.102+.105+.033- Blue Jay 12.022+ Dark-eyed Junco 12.038-.010+.005+.011+.072-.041- Downy Woodpecker 12.012+.015- Mourning Dove 10.003+.020+.105+.086-.098- White-throated Sparrow 9.031+.086+ Herring Gull 8.002-.038-.003+ Red-tailed Hawk 8.080-.086- House sparrow 6 Rock Dove (Pigeon) 6.023-.053+<.0001+.0002+.055- American Goldfinch 5 Northern Mockingbird 4 Pileated Woodpecker 4.022+.078+ Red-bellied Woodpecker 4.092+

15. Significant Results (small sample sizes make results provisional!) (using Chi2 or backwards anova) Species NPctTrees (300 m) PctTrees (600 m) PctTrees (900 m) PctTrees (1200m) American Crow 56 <.0001 - Black-capped Chickadee 44 White-breasted Nuthatch 20 European Starling 14.103 -.-17 -.015 -.092 - Tufted Titmouse 14.044+.067+.072+.092+ Northern Cardinal 13 Blue Jay 12 Dark-eyed Junco 12.041 -.037 -.076 -.053 - Downy Woodpecker 12 Mourning Dove 10.049 -.053 -.168 -.189 - White-throated Sparrow 9.090 -.189 - Herring Gull 8.010 -.025 -.004 - Red-tailed Hawk 8 House sparrow 6.052 -.039 -.022 -.009 - Rock Dove (Pigeon) 6.001 - American Goldfinch 5 Northern Mockingbird 4 Pileated Woodpecker 4.048 +.074 + Red-bellied Woodpecker 4

16. SpeciesTempFeederGrassTreesShrubsPavementPctRoads (300 m) PctRoads (600 m) PctRoads (900 m) Distance to roads Parcel size Urban.0001-.002 -.0001+.0003+.0001+.055-.017- Suburban.069- SpeciesPctTrees (300 m) PctTrees (600 m) PctTrees (900 m) PctTrees (1200m) Urban<.0001 - Suburban Urban vs. Suburban groups

18. Scale patterns Species NPctTrees (300 m) PctTrees (600 m) PctTrees (900 m) PctTrees (1200m) American Crow 56 <.0001 - Black-capped Chickadee 44 White-breasted Nuthatch 20 European Starling 14.103 -.017 -.015 -.092 - Tufted Titmouse 14.044+.067+.072+.092+ Northern Cardinal 13 Blue Jay 12 Dark-eyed Junco 12.041 -.037 -.076 -.053 - Downy Woodpecker 12 Mourning Dove 10.049 -.053 -.168 -.189 - White-throated Sparrow 9 Herring Gull 8.010 -.025 -.004 - Red-tailed Hawk 8 House sparrow 6.052 -.039 -.022 -.009 - Rock Dove (Pigeon) 6.001 - American Goldfinch 5 Northern Mockingbird 4 Pileated Woodpecker 4.048 +.074 + Red-bellied Woodpecker 4

19. Ubiquitous species

20. Feeder species

21. Woodland species

22. Urban species

24. Christmas Bird Count results Number in 2004

25. Conclusions: 1. Native species, woodland species show relatively little effect on the range of urbanization gradients in the study area Urban species, including invasives, show relatively large effects ----------- 2. Percentage road area = easy to calculate, useful factor Distance = not useful in suburban contexts (gradients too small) Parcel size = easy to calculate but less useful than road area All of these are easier to assess accurately than LULC or digitized tree cover. BUT tree cover is still generally more influential ----------- 3. Despite small samples, trends were consistent over scales Focal statistics is a useful, easy approach to multiple-scale studies