1. Tucson’s Birds: Why Scale Matters Rachel McCaffrey

2. In developed areas, factors controlled by humans are important to determining whether native bird species persist Vegetation –Volume –Composition –Diversity Land-use –Types –Arrangement –Intensity Bird Occurrence Abundance Diversity Composition

3. Volunteer-based bird survey program Abundances and distribution Annual, citywide count ~ 1,000 sites, 1/km 2 Quarterly, “Park” count ~ 200 sites at 30 locations

4. Annual Survey Sites

5. Park Monitoring Sites

6. Research Focus Birds and habitat features in residential developments: an issue of scale

7. What we know: Urban areas have less diverse groups of birds ↑ in non-native species Some types of development support more native birds

8. Scale is important! urban areas = heterogeneity and disturbance (Hostetler 1999)

9. Local vs. landscape features Individual yardsSurrounding area Species Dependent!

10. Why is this important? which features @ which scale = species and scale-specific management guidelines homeowners neighborhoods planners

11. Study Design Randomly selected 300 sites

12. Bird surveys 5-minute point count, 40 m radius Each site surveyed 4 times, March 15 – June 15 10 species

13. Habitat features - Local 0.5-ha circular plot (40 m radius) –Represents typical residential lot –On-site measurements Features measured based on known habitat requirements of species

14. Habitat features - Local Number of: –cholla cacti (> 1m) –saguaro cacti (> 2m) –mesquite and palo verde trees (> 3m) –native thorn trees (> 2m) –large “roost” trees (> 5m) –palm trees (> 5m) –homes Presence of: –desert mistletoe –wash Percent of vegetation that is native

15. Habitat features - Landscape 50-ha circular plot (399 m radius) –Represents typical neighborhood/development –Used digitalized aerial photographs & GIS Features measured based on habitat requirements and management potential

16. number of washes percent of area in open space percent of area covered by lawn presence of natural area > 5 ha Habitat features - Landscape

17. Regression analyses: Which features are most important for each species at each scale? Variance decomposition: Was a species most influenced by features at the local or landscape scale? Data Analysis

18. Results Average of 5.5 species/site 21.6% of sites 87.8% of sites

19. Results – Local Scale number of thorn trees number of cholla number of mesquite and palo verde trees overall percent native vegetation number of homes

20. Results – Landscape Scale number of washes (4) percent of area in open space (6) percent of area covered by lawn (3)

21. Results - Scale Species most influenced by local scale features: Cactus wren Curve-billed thrasher Phainopepla

22. Cactus wren 0 20 40 60 80 100 01-34-67-910-1213-1516-1819+ Number of cholla Percent of sites with cactus wrens

23. Results - Scale Species most influenced by landscape scale features : Ash-throated flycatcher Lesser goldfinch

24. Ash-throated flycatcher 0 10 20 30 40 01234+ Number of washes Percent of sites with Ash-throated Flycatchers

25. Results - Scale Species most influenced by shared associations: Gambel’s quail Gila woodpecker Northern cardinal Pyrrhuloxia Verdin

26. Pyrrhuloxia Influenced most by shared associations across scales…… Local: % native vegetation Landscape: % open, % lawn (-) E.J. Peiker

27. The Influence of Scale Importance of habitat features varied by species and scale Cross-scale interactions Need scale-specific management strategies!

28. Local scale implications Individual homeowners can have an impact! plant thorn trees, cholla, native trees

29. Landscape scale implications Neighborhood groups and developers of master-planned communities can take broader actions: ban/limit lawns promote native landscaping incorporate open space restore riparian areas

30. A multi-scale approach Homeowner plants thorn trees Development incorporates open space Regional planning efforts to maintain riparian networks

31. In Conclusion….. The persistence of many native birds in urban areas will depend on: Identifying key habitat features Understanding the relevant scales Targeting management efforts